Norm Pyle's Hops FAQ

Hop Vine

Compiled/edited by Norm Pyle, 5/4/95


This revision reviewed by Glenn Tinseth
Send feedback to: gtinseth (at) yahoo (dot) com

Table of Contents

  • Forward
  • What Are Hops?
  • Bittering Compounds
  • Aroma and Flavor Compounds
  • Different Hop Products
  • Estimating Bitterness
  • How Bitter Should It Be?
  • Storing Hops
  • Growing Hops
  • Dry Hopping
  • What is a "Hop-back"?
  • Wet vs. Dried Hops?
  • Hop Varieties and How to Use Them
  • Contributors
  • Forward

    This is the fifth revision of this document. I've added several varieties of not-so-well-known hops from the UK and New Zealand, including as much information as I could find. Since information is in short supply on some of these hops, you'll see more instances of "???". If you have information to fill in some of the blanks, please send it along. I've also attempted to clarify and simplify (if that's possible) the bitterness calculations, while providing several different approaches.

    I've moved the list of contributors to the end, since the intended audience probably cares more about the information than who provided it. Don't misunderstand the importance of these contributors, though. Those listed have been absolutely essential in bringing this information together. Again, if you've contributed to this FAQ, don't see your name listed, and would like it listed, please contact me. No slight was intended, but with so much information from so many sources, it is easy to lose a name. Also, if your email address has changed, it would be nice to update that.


    What Are Hops?

    Hops are cultivated flowers (humulus lupulus), green in color with yellow lupulin glands down between the petals, used for preservative and flavoring characteristics in beer. The bitterness of the hop is used to balance the sweetness of the malt, and the essential oils add a flavor/aroma which cannot be achieved by using any other plant. The hop plant is a perennial spiraling vine which will grow in almost any climate given enough water and sunlight. It can climb either string or poles and can reach heights of 40 feet. The flowers (or cones as they are often called) are usually dried before use.

    Bittering Compounds

    One of the major contributions hops give to beer is a characteristic bitterness that provides a counterpoint to the rich sweetness provided by the malt. This bitter flavor is extracted from the hops during the boil. It is during this time that virtually insoluble alpha acids are isomerized (rearranged without changing their composition) into more soluble and stable iso-alpha acids, the main bittering substance in beer. Five different naturally occurring alpha acids have been isolated from hops which are:


    Although isomerized alpha acids are the biggest contributers, hops contain beta acids which also add bitterness to beer. The beta acids are similar to alpha acids both in structure and abundance. In contrast to alpha acids, it is not isomerized beta acids that add bitterness, it is the oxidation products of the beta acids, which are bitter and soluble, that make their presence felt. It should be noted that oxidized beta acids are not as bitter as isomerized alpha acids, and thus contribute much less to the final bitterness of the beer.

    Both the alpha and beta acids are very susceptible to oxidation, especially at temperatures above freezing. Theoretical losses of alpha acids of up to 60% have been calculated for hops which are packaged and stored poorly. This is important because once alpha acids have been oxidized they can no longer be isomerized into iso-alpha acid, thus decreasing the hop's bittering potential. As stated above, oxidation components of beta acids contribute to bitterness, thus the bittering potential of oxidized hops may not decrease as much as is commonly thought. This does not, in any way, argue against storing hops well, since essential oils are dramatically and negatively altered by oxidation.

    For these reasons, the "storageability" of each hop variety is sometimes provided, along with the alpha and beta acid levels, by the hop broker. This parameter is usually given as a percentage of the alpha acids present after 6 months at 20C. Some good storage hops (usually high alpha acid) lose only 15-20% of their alpha acids: Cluster and Galena are among the best. Most high quality aroma hops lose anywhere from 35-65% of their alpha acids unless anaerobic conditions and cold storage (< 0C) are provided. This is why it is imperative for brewers to buy the freshest hops available and store them in the coldest environment available, usually the freezer. It is also important to package the hops properly, which means removing as much oxygen as possible and containing them in an oxygen barrier material.

    Aroma and Flavor Compounds

    Hops bring a lot more to beer than bitterness. The volatile oils, usually 0.5 - 3.0% (vol/wt) of the hop cone, are an important flavor component of many types of beer. Brewers seeking to maximize hop flavor and aroma generally make late kettle additions (0-15 min. before cooling) with high quality "aroma" hops. Dry hopping, i.e. the addition of hops to the secondary fermenter or serving tank, is another way to add hop character to a beer although the aroma components retained by this method differ from those obtained in late kettle additions. The maximum oil utilization is about 10 - 15% which decreases with increased boiling time.

    The essential oils are what give hops their unique aroma; each variety has its own distinct profile. The smell of hops freshly crushed in your hand is quite often different than that in a finished beer. This is due to the fact that the major components in hop oil, beta-pinene, myrcene, beta- caryophyllene, farnesene and alpha-humulene, are not usually found in beer. This is also the reason that measures of "total hop oil percentage" that some hop retailers provide are considered by some to be useless information. On the other hand, fermentation and oxidation products of these compounds, especially humulene epoxides and diepoxides are considered contributors to "hoppy" flavors and aroma. The exception here is with dry-hopping, where some of the hop oil components do survive into the beer intact.

    Researchers have not been able to duplicate the complexities of hoppy character by adding pure chemicals in any proportion or combination. Consensus is that there is a synergistic blend of several compounds, some of which may have not yet been discovered.

    Hop researchers, using capillary gas chromatography, have detected and identified more than 250 essential oil components in hops. Twenty two of these have been pinpointed as being good indicators of hoppiness potential. They are subdivided into 3 groups, humulene and caryophyllene oxidative products, floral/estery compounds, and citrus/piney compounds, as listed below:

    Oxidation Products:

    caryophyllene oxide
    humulene diepoxide a
    humulene diepoxide b
    humulene diepoxide c
    humulene epoxide I
    humulene epoxide II
    humulene epoxide III
    humulenol II

    Floral/Estery Compounds:

    geranyl acetate
    geranyl isobutyrate

    Citrus/Piney Compounds:


    Different Hop Products

    Much has been written about what form of hops should be used. Loose hops are just that: loose cones which have been dried after picking. Plugs are loose hops which have been subsequently pressed into a bung under pressure, generally in 0.5 oz. sizes. Pellets are loose hops which have been ground to a fine powder and then pressed into rabbit-food-sized pellets.

    Loose Hops

    Advantages: They are the most natural form of the ingredient. They float, which is good for siphoning out from under, and form a natural filter bed. When they are fresh, they beat all other forms in delivering the original hop compounds to the beer (processing hops alters the volatile hop compounds in many ways).

    Disadvantages: They float, so some contact with a still wort (as in dry hopping) is thought to be lost; this disadvantage is certainly arguable though, especially when it is considered that by using weighted hop bags, it is a non-issue. Since they are loose, exposure to air (oxygen) may be greater which could cause them to lose quality more quickly than the other forms of hops (note that this point is debatable). When stored in vacuum- sealed or CO2 or nitrogen purged Oxygen barrier bags or jars, this potential problem can be avoided. They are bulkier than other forms.


    Advantages: Are nearly the same as loose hops, in that, when hydrated, they become whole hop cones again. Like loose hops, they float. They may be better protected from air, but this is unproven.

    Disadvantages: Few hop varieties come in this form. Currently, any domestic varieties are first shipped to England where they are made into plugs and then shipped back to the U.S. This probably negates any potential freshness advantage they have over loose hops (for U.S. varieties). It is difficult, but not impossible to separate into increments smaller than 0.5 oz. The compression of the hops into this form causes the lupulin glands to burst, which causes a finite loss of the volatile hop aromatic compounds and could cause increased alpha acid oxidation.


    Advantages: Convenient to measure and may have better protection from air (another unproven assumption). They sink, so they get maximum contact in a still wort, as when used for dry hopping (may or may not be an advantage). If they are subsequently covered with dead yeast, wort contact is mostly lost, so careful timing is recommended when using them for dry hopping. They reportedly contribute 10% more alpha acids to the wort because of maximized surface area, so are a more efficient use of this relatively expensive ingredient. They are generally available in more varieties.

    Disadvantages: They sink and are powdered, so it is difficult to avoid them when siphoning. The extra processing of chopping and compressing negatively affects hop compounds.

    Given the pros and cons listed, the choice of which form of hop to use in a certain application is up to the individual brewer and dependent upon the individual brewhouse. With some kettle arrangements (those using a hopback, for instance) loose hops can form a utilitarian filter bed. In others, the mass of loose hops can be a nuisance and soak up a large quantity of wort which is lost to the brewer. It should be noted that fresh, whole hops are available today from many sources, including mail-order nationwide (US) from companies such as Just Hops, Freshops, and HopTech, which may negate many of the advantages of processed hops.

    Estimating Beer Bitterness

    The simplest way to describe the bittering potential of a given hop sample is to use Alpha Acid Units (AAU) or Homebrew Bittering Units (HBU) (they're the same). For the sake of discussion we will use the term AAU, which is calculated as follows:

    AAU = AA * W


    AAU's are literally hundredths of an ounce, so the units would be ounces. This is a bit awkward, and they are usually discussed as if they are "unit-less". It is generally assumed that, when using AAU or HBU, the batch size is the standard homebrewing unit of 5 gallons. If a beer is said to have 10 AAU's of bitterness in it, and it is a 5 gallon batch, there would probably be no confusion. On the other hand, if it is a 10 gallon batch, there is actually half the AAU's per gallon when compared to the 5 gallon batch and the beer would be quite different. Another drawback to using AAU's is that they don't consider the utilization obtained from long, intermediate, or short boil times. Fudge factors are sometimes added but at best they offer a rough approximation.

    To help solve these problems, the International Bittering Unit (IBU) may be used. An IBU is defined as 1 mg/l of iso-alpha-acid in a solution. By estimating IBUs rather than HBUs, the brewer can get a more accurate (though admittedly still rough) approximation of the bitterness imparted into the beer by the hops. It is independent of batch size so that a 5 gallon batch with 29 IBU's has the same bitterness as a 50 barrel batch with 29 IBU's. The equations are commonly quoted from Jackie Rager's article in the "Zymurgy" Hops and Beer Special Edition published in 1990. Revised numbers and formulae have recently been presented by Glenn Tinseth and Mark Garetz, in separate works. Rager has been taken to task for not supplying enough background references, and not fully explaining how he got his numbers. In general, his utilization estimates are believed to be optimistic. Garetz has been accused of extrapolating scant laboratory information, and overgeneralizing because of it. His numbers have been labelled unrealistic on the pessimistic side. Tinseth has just presented a revised method and set of tables, and though they are thought to be quite accurate, they have not stood the test of time. The calculated numbers tend to fall in between Rager's and Garetz's. Note also that these are all estimates. Actual IBUs can be measured in a laboratory, but the average homebrewer has no access to such equipment. The Rager, Garetz, and Tinseth estimation methods follow.

    Rager Method

    Boiling Time (minutes) %Utilization
     0 -  5                       5.0
     6 - 10                       6.0
    11 - 15                       8.0
    16 - 20                      10.1
    21 - 25                      12.1
    26 - 30                      15.3
    31 - 35                      18.8
    36 - 40                      22.8
    41 - 45                      26.9
    This utilization can be reduced to a smooth function, as opposed to the table, which produces many discontinuous lines. The Rager table is represented by the following utilization equation:

    %UTILIZATION = 18.11 + 13.86 * hyptan[(MINUTES - 31.32) / 18.27]
    According to Rager, if the gravity of the boil exceeds 1.050, there is a gravity adjustment (GA) to factor in:

    GA = (BOIL_GRAVITY - 1.050)

    GA = 0
    Metric Units
                     VOLUME(litres) * (1 + GA)
    Non-metric Units
                     VOLUME(gallons) * (1 + GA)
    Jackie Rager's numbers have been used successfully by thousands of homebrewers and provide a consistent base with which to work. Note that the figures expressed as percent should be entered as decimal values in the formula (9% = 0.09). It is apparent that his constant 7462, derived from metric to US conversion, is actually closer to 7490. The GA factor could be questioned as well, as it is intuitively obvious that a gravity of 1.049 does not affect utilization exactly the same as a gravity of 1.000 (water). It is assumed (but not verified) that the utilization table is corrected for this assumption and/or the difference is small enough that it has little effect on the final bitterness of the beer.

    The unfortunate part of Rager's article is that it is completely lacking in references, so assumptions come with it part and parcel. Note also that Rager's numbers are often used for pellet hops thrown loose in the boil. Al Korzonas suggests adding 10% more hops if used in a hop bag, and 10% more than that if loose hops or plugs are used.

    Garetz Method

    It has been reported that since iso-alpha acids possess a slight electrical charge, they can be lost in many ways. Among these are absorption into the yeast cell walls (and subsequent removal of the yeast), attachment to coagulating proteins (and subsequent removal of this trub), attachment to filters, etc. It is unclear if Mr. Rager's utilization numbers have assumed these losses, but it can be assumed that Tinseth and Garetz did take them into account. The Garetz numbers below represent average yeast flocculation; he also provides tables which represent fast and slow yeast flocculation.

    Boiling Time (minutes) %Util (Avg Yeast)
     0 -  5                    0
     6 - 10                    0
    11 - 15                    2
    16 - 20                    5
    21 - 25                    8
    26 - 30                   11
    31 - 35                   14
    36 - 40                   16
    41 - 45                   18
    46 - 50                   19
    51 - 60                   20
    61 - 70                   21
    71 - 80                   22
    81 - 90                   23
    According to Garetz, there are several adjustment factors, that he brings together in the formula with the term "combined adjustments" (CA):

    CA = GF * HF * TF
    where GF is the Gravity Factor, HF is the Hopping Rate Factor, and TF is the Temperature Factor. To calculate it all, he starts with some he calls CF:

    Concentration Factor:  CF = Final Volume / Boil Volume,
    to account for concentrated boils of extract brews.

    Next, calculate Boil Gravity (BG):

    BG = (CF * (Starting Gravity - 1)) + 1
    Then calculate GF:

           BG - 1.050
    GF  =  ----------  + 1
    HF is calculated as follows:

    HF  = ((CF * Desired IBUs)/260) + 1
    TF is based on elevation as follows:

    TF  = ((Elevation in feet) / 550) * 0.02) + 1
    These are all put into the following formula, along with the utilization from the table, and the IBUs are calculated. Note two things: 1) the utilization and alpha acids should be expressed as whole numbers (7% = 7), and 2) this process is iterative, since it contains a term (HF) based on your goal IBUs. You must guess at the final result, do the math, and rerun the process, each time adjusting the value downward. It takes a little practice, but can be done.

    Metric Units
    IBU = (%Utilization) * (%Alpha) * Hop weight(grams) * 0.1
                           Volume(liters) * CA
    Non-Metric Units
    IBU = (%Utilization) * (%Alpha) * Hop weight(ounces) * 0.749
                           Volume(Gallons) * CA
    Garetz goes to allow for a yeast factor (YF), pellet factor (PF), bag factor (BF), and filter factor (FF), and comes up with:

    CA = GF * HF * TF * PF * BF * FF
    This allows you to adjust the formula based on your own brewery and practices.

    Tinseth Method

    Glenn Tinseth's method doesn't involve as many factors, but is still a bit more complex than the original Rager method.Tinseth notes that his table is optimized for fresh whole cones loose in the boil, although easily adjustable for other forms of hops. He builds the gravity adjustment into the utilization tables and offers the following:

    Decimal Alpha Acid Utilization vs. Boil Time and Wort Original Gravity
    Boil	Original Gravity									
    Time	1.030	1.040	1.050	1.060	1.070	1.080	1.090	1.100	1.110	1.120	1.130
      0	0.000	0.000	0.000	0.000	0.000	0.000	0.000	0.000	0.000	0.000	0.000
      3	0.034	0.031	0.029	0.026	0.024	0.022	0.020	0.018	0.017	0.015	0.014
      6	0.065	0.059	0.054	0.049	0.045	0.041	0.038	0.035	0.032	0.029	0.026
      9	0.092	0.084	0.077	0.070	0.064	0.059	0.054	0.049	0.045	0.041	0.037
     12	0.116	0.106	0.097	0.088	0.081	0.074	0.068	0.062	0.056	0.052	0.047
     15	0.137	0.125	0.114	0.105	0.096	0.087	0.080	0.073	0.067	0.061	0.056
     18	0.156	0.142	0.130	0.119	0.109	0.099	0.091	0.083	0.076	0.069	0.063
     21	0.173	0.158	0.144	0.132	0.120	0.110	0.101	0.092	0.084	0.077	0.070
     24	0.187	0.171	0.157	0.143	0.131	0.120	0.109	0.100	0.091	0.083	0.076
     27	0.201	0.183	0.168	0.153	0.140	0.128	0.117	0.107	0.098	0.089	0.082
     30	0.212	0.194	0.177	0.162	0.148	0.135	0.124	0.113	0.103	0.094	0.086
     33	0.223	0.203	0.186	0.170	0.155	0.142	0.130	0.119	0.108	0.099	0.091
     36	0.232	0.212	0.194	0.177	0.162	0.148	0.135	0.124	0.113	0.103	0.094
     39	0.240	0.219	0.200	0.183	0.167	0.153	0.140	0.128	0.117	0.107	0.098
     42	0.247	0.226	0.206	0.189	0.172	0.158	0.144	0.132	0.120	0.110	0.101
     45	0.253	0.232	0.212	0.194	0.177	0.162	0.148	0.135	0.123	0.113	0.103
     48	0.259	0.237	0.216	0.198	0.181	0.165	0.151	0.138	0.126	0.115	0.105
     51	0.264	0.241	0.221	0.202	0.184	0.169	0.154	0.141	0.129	0.118	0.108
     54	0.269	0.246	0.224	0.205	0.188	0.171	0.157	0.143	0.131	0.120	0.109
     57	0.273	0.249	0.228	0.208	0.190	0.174	0.159	0.145	0.133	0.121	0.111
     60	0.276	0.252	0.231	0.211	0.193	0.176	0.161	0.147	0.135	0.123	0.112
     70	0.285	0.261	0.238	0.218	0.199	0.182	0.166	0.152	0.139	0.127	0.116
     80	0.291	0.266	0.243	0.222	0.203	0.186	0.170	0.155	0.142	0.130	0.119
     90	0.295	0.270	0.247	0.226	0.206	0.188	0.172	0.157	0.144	0.132	0.120
    120	0.301	0.275	0.252	0.230	0.210	0.192	0.176	0.161	0.147	0.134	0.123
    To calculate IBUs, the formula is simple:

    IBUs = decimal alpha acid utilization * mg/l of added alpha acids
    For those who want to make adjustments based on their own brewery, he offers the following:

    Metric Units
    mg/l of added alpha acids = decimal AA rating * grams hops * 1000
                                            liters of wort
    Non-Metric Units
    mg/l of added alpha acids = decimal AA rating * ozs hops * 7490
                                            gallons of wort
    The decimal alpha acid utilization is calculated using Tinseth's two empirical factors: the Bigness factor and the Boil Time factor.
    Decimal Alpha Acid Utilization = Bigness Factor * Boil Time Factor

    The Bigness Factor accounts for reduced utilization due to higher wort gravities.

    Bigness factor = 1.65 * 0.000125^(wort gravity - 1)
    The Boil Time Factor gives the varying utilization based on boil time:

    Boil Time factor = 1 - e^(-0.04 * time in mins)
    Some comments from Tinseth:

    "The numbers 1.65 and 0.000125 are empirically derived to fit my data. The number 0.04 controls the shape of the util vs. time curve. The factor 4.15 controls the max util value--make it smaller if your util is higher than mine.

    I'd suggest fiddling with 4.15 if necessary to match your system, only play with the other three if you like to muck around. I make no guarantees if you do.

    You might notice that the shape of the util curves is very similar to that of Randy Mosher's. He and I seem to have independently arrived at the same conclusion.

    The really cool thing about these new equations is that they are easily customizable. I believe the basic form is correct--by playing with the different factors, different brewers should be able to make them fit their breweries perfectly. The root of the equations is the basic first order chemical reaction, i.e. the AA isomerization seems be first order (or pseudo-first order)."

    Bitterness Summary
    It should be obvious that the alpha acid utilization is a widely debated topic, and that it is not an exact science. Homebrewing systems vary so widely that it is impossible to be very accurate with the IBU estimates. The homebrewer who strives to be accurate within 10% of actual can probably achieve it, and verify it with known commercial examples. The human tongue is accurate enough for this delightful experiment. Precision with IBUs is certainly achievable, with careful record-keeping, including personal sensory descriptions, and the use of a consistent set of formulae and utilization tables. These steps will go a long way toward consistent quality beer.

    One question that appears on occasion is whether you lose bitterness if you boil the hops for too long, e.g. longer than two hours. According to Glenn Tinseth, multiple studies have shown that alpha acid utilization always increases with boil time, even out to 3 hours of boiling. The reason the tables quit around 60 minutes of boiling, is that little utilization is gained beyond that. In fact, after about 45 minutes the curve becomes quite flat. In other words, beyond that the utilization increase is small compared to the added time involved. It is speculated that commercial brewers found that beyond 45-60 minutes or so, the benefit of the added utilization was more than offset by the cost of the energy to continue the boil as well as the cost of the added time in the process.

    A final note about bitterness: IBUs are not the final word when it comes to the perceived bitterness of beer. Sulfates, dark grains, tannins, and other compounds found in beer contribute to the bitterness sensation. For this reason, comparison of bitterness between styles (and sometimes even different beers within a style) is difficult.

    How Bitter Should It Be?

    The AHA and probably other organizations publish (large) charts which define the range of IBUs expected in a given style. It is outside the scope of this FAQ to go into that much detail on beer styles, but hopping rates from 10 IBU to 60 IBU or more have been noted in commercial beers. The following table from an article titled "Matching Hops with Beer Styles" by Quentin B. Smith in the 1990 "Zymurgy" Hops and Beer Special Issue may help. Other factors are just as important as OG, such as FG, sulfate content of the water, and the style of beer, but this will get you started:

    Balanced Beer Hop Chart

            Wort OG             IBU
            -------             ---
            1.010                4
            1.020                8
            1.030               12
            1.040               16
            1.050               24
            1.060               32
            1.070               40
            1.080               48
            1.090               56
            1.100               64

    Storing Hops

    Store hops at as low a temperature as possible, hopefully in your freezer. Also, attempt to remove as much air as possible from the package and use airtight, preferably oxygen-barrier packages.

    Growing Hops

    Hops for beer-making grow from the rhizomes of female hop plants. Rhizomes look like root cuttings but have buds growing from them that will become new vines. Rhizomes also contain stored nutrients to support initial growth.

    Hops grow vertically as one or more vines that spiral up a twine or other support. Depending on latitude, location, and variety, they sprout from March or April and grow through the summer and early fall. A single plant can easily grow 40 feet tall when it is mature but growth in the first year is usually much less. In most instances by the second or third year the plants will exhibit full growth. Height is very closely linked to the amount of sunshine the plant gets.

    Hops grow best in full sun and you should pick a spot with the best possible southern exposure. Hops grow best in loose, well drained soil. Blended peat moss and sand make a good growing environment. In cases of poor soil drainage, it can be helpful to create a mound of soil a foot or so tall which will aid drainage.

    Hops need lots of water. As they grow be sure to give them a very good soaking at least once a week. There are reports that once-a-day waterings (up to 6.5 gallons per mound) give greater growth and yield. Mulch in the summer helps with weed control and also holds water. Hops also have big appetites; composted cow manure is an excellent well-balanced fertilizer for them.

    Once a bed has been prepared the rhizomes are planted about 4 inches below the soil surface with any obvious buds coming from the rhizome oriented to point upward.

    After several inches the new vines can be thinned so that just the most healthy and vigorous three vines are left to continue growing. This will be an ongoing process as new shoots may show up later, but the initial thinning is thought to be important by some home hop growers. It's been reported that the young shoots that are culled may be steamed and eaten like asparagus. On the other hand, some growers espouse cutting the new shoots at all, allowing all vines to grow to full height.

    As the vines grow over a foot tall they should be trained to grow up a twine. This can be done by twisting the vine around the line. This may have to be repeated for a few days before the vine gets the idea. Hops will have a natural tendency to wrap clockwise looking down.

    The most common hops trellis consists of strings running from the roof of a building down to stakes driven into the soil near the plants. Another option, often used by commercial growers, consists of a large central pole, with strings running from the top of the pole down to the foot of each plant, similar to the spokes on a wheel. Expect the string or twine to hold a lot of weight as the vines grow tall. A 25+ foot plant may weigh 20+ pounds.

    Hop blossoms start out looking like large sand burrs, and then take on a characteristic cone shape as they grow in size. The size of a fully developed cone depends on the variety, varying from 1 to 2 inches long by 1/2 to 1 inch in diameter.

    The hops are fully mature and ready for picking when two changes take place. First, immature hops have a damp, soft feel and when squeezed slightly tend to stay compressed. Mature hops feel more like paper, spring back when squeezed, and feel noticeably lighter. The second key test is to pick an average example hop and cut it lengthwise down the center with a knife. When ready to pick, the yellow powder (the lupulin sacs containing the essential oils and bitter compounds) will be a dark shade of yellow, like the stripes on a highway, and it will be pungent. If a light shade of yellow then its likely the hops are immature.

    When ready to pick it is best to snip the stems of the cones with scissors or a knife to avoid jarring the hops and knocking lupulin powder out or worse, pulling the center of the cone out with the stem, causing a great loss of lupulin. Touching hops plants can cause skin irritation in some people; gloves and long sleeves can help in this matter.

    Just-picked hops are roughly 80 percent water; if left alone they spoil rapidly. For proper storage most of the water is removed by drying. A good drying method is to lie the hops on a card or screen in an attic. Just a few hours during the heat of summer or a few hours more in cooler weather is enough to dry the hops. Use a before and after weighing (and trial and error) to try to achieve about 7-10 percent residual moisture after drying.

    After drying, hops keep best at low temperatures and away from oxygen. A kitchen freezer easily takes care of temperature but to get the hops away from oxygen is difficult. Tightly packing hops in canning jars will minimize the trapped air but be careful not to use too much force and break the all important lupulin sacs since this accelerates oxidation. Purging the canning jar of oxygen by blowing in carbon dioxide from a kegging system will also help prolong freshness.

    It's common to get 4 or 5 harvests per year by picking the biggest, most mature hops every 2 weeks or so as the flowers ripen. Patience and judgement are important since cones left on the vine too long turn brown and begin to oxidize and spoil, while immature hops have little lupulin to give.

    At the end of the growing season when the leaves have fallen or turned brown, cut the vines at the surface of the soil and if possible remove the twine. After cutting back the vines a layer of 3 or 4 inches of mulch and composted manure can be put over the exposed vines for insulation and nutrition during the winter.

    Japanese beetles are the number one nuisance in many areas. A common remedy is to position a "Bag a Bug" type beetle trap about 30 feet directly up wind from the hop vines. There is some concern that the "Bag a Bug" traps may actually attract more beetles than they catch, but that probably depends on the situation. Certain plants such as rose bushes may also attract the beetles, so it's best to keep those plants away from your hops. Also, the beetles' larvae live in the ground, and in cases of extreme Japanese Beetle infestation the surrounding lawn may need to be treated accordingly. A number of other pests, such as aphids, can harm hops, and can be treated with any number of pesticides. Since you will be consuming these hops, you should use low toxicity natural pesticides, such as 1% Rotenone dust, for direct pest control on the plants. As with any consumable, you should ensure that any pesticide is well washed before using the hops.

    Ladybugs are the best, most natural way to get rid of aphids and a lot of other bugs. However, it can be difficult to keep them on your hop plants once you run out of food for them. A good idea is to plant some cilantro/coriander between your hop hills. Ladybugs are attracted to this plant and it will keep their attention between feedings of aphids. You can even harvest the cilantro (the leaves) for cooking and use the coriander (the seeds) in Witbier.

    One other hazard is animals. A short fence of rabbit wire will keep cats, dogs, rabbits, etc. at bay, but won't do much against deer.

    Rhizomes are available from an increasing number of sources. American Brewmaster in Raleigh, NC, and Freshops in Philomath, OR, are all well-known suppliers. Cost is usually a few dollars each. They should be kept in plastic bags, moist and cold in your refrigerator until they are planted.

    Additional information about hop growing can be found in "Homegrown Hops" by David R. Beach. Also, the 1990 Zymurgy Hops and Beer Special Issue is devoted to hops and contains an article about growing hops by Pierre Rajotte. The AHA also has additional hops-oriented publications.

    Dry Hopping

    Dry hopping can be defined as adding hops to a cooled wort at sometime during the fermentation process. It can be thought of as "cold-hopping" or "raw-hopping", as these hops do not "cook" like the kettle hops. It adds a fresh hops aroma/flavor to the beer which cannot be matched with hop additions into hot wort. It is not to be confused with finish/aroma hopping, which is done on the hot wort while still in the kettle. The use of a hop-back, where hot wort is passed through the hops, is another form of finish hopping; it is not dry hopping. Dry hopping gives no alpha acids to the wort, but it may contribute some oxidized beta acids; its bittering contribution to the final product is very small. It is more likely to add a perceived bitterness with the addition of the intense aroma rather than an actual bitterness due to bitter acids.

    There are several ways to dry hop, if one considers the variations of making hop teas, etc. The best time to dry hop is after primary fermentation has slowed and little CO2 is being driven off the wort. Dry hopping earlier than this point is inefficient as the volatile hop oils are scrubbed away by the exiting CO2. Also, dry hopping early in the fermentation phase may result in hops on the bottom of the fermenter being covered with yeast, which results in inefficient extraction of aroma. Another consideration of timing dry hopping is with infection risk. Hops in contact with boiling wort are effectively sanitized. Addition of dry hops after primary fermentation allows them to contact a wort/beer with some alcohol and less sugar, which prevents infections from getting a foothold.

    The proper length of time for dry hopping is dependent on the temperature. At ale temperatures, 7-14 days of contact time is widely used. At lager temperatures, although little data is available as few lagers are dry hopped, it seems obvious that longer contact times, on the order of 14-21 days, are called for. It is common to use 0.5 - 2.0 oz. or more in a 5 gallon batch, but as always it is up to the individual's preferences and the hop variety. An ounce or more of East Kent Goldings in the secondary will add a nice aroma, but probably not overpowering to most brewers. A similar amount of Cascades, on the other hand, are not for the faint of heart! The rare commercial brewer that dry hops generally leaves the hops on the beer for a longer time than the average, impatient homebrewer. This is undoubtedly to extract more aroma from this relatively expensive ingredient.

    EKGs, Fuggles, Northern Brewer, Saaz, Cascade, all Hallertauer variants, and many other hops have been used successfully. It should be noted that the aroma of the beer greatly influences the profile, and that the "correct" aroma hop should be used to match the style (i.e. English hops for English ales). American brewers have traditionally used hops from all over the globe so European hops, for example, can be used without fear of a brewing faux pas. Note also that traditionally, German beers are not dry-hopped, but that American versions of German styles are sometimes dry hopped.

    The first and foremost way to dry hop is to simply put the hops into the fermenter. The most common worry with this method is about infecting a beer which is nearly ready to bottle/keg. Hops are natural preservatives, and infections from this method are very rare. Of course, an infection source in a homebrewery is impossible to prove, but this risk is certainly minimal. If loose hops or plugs are used, they will float, and some brewers use a sanitized hop bag and marbles to sink the hops for maximum contact. If pellets are used they will sink, but may be difficult to avoid when bottling or kegging. Also, the pellet hops can be easily covered by yeast falling out of suspension, so they should be added after virtually all fermentation activity has ceased, and a good amount of the yeast has fallen. Finally, it is worth mentioning that, for many, pellets are not well regarded for dry hopping because the pelletization process is known to be very rough on the volatile aromatic compounds which the brewer is attempting to capture. Others swear by them, claiming the pre-burst lupulin glands provide more aroma to the beer.

    Another method used to dry hop is to steep the hops in a white alcohol (grain, vodka, etc.) and sometimes water solution for hours or days, then pour this solution into the fermenter. This is a common practice among those who want to protect against the remote possibility of infection with normal dry hopping. It should be noted that as the temperature of the alcohol/water/hops mixture is raised, the effect approaches that of finish hopping, as the most volatile hop oils are driven off.

    Adding hop oil, a product recently introduced to the homebrewing market, is another way of "dry-hopping". It should be done after primary fermentation has slowed for many of the same reasons.

    These dry hopping methods, and others, will produce different results, mainly because the desired compounds are so volatile. The variety of reactions taking place during processing and fermentation will affect the results. Some have noted grassy and otherwise unpleasant aromas from the practice of dry hopping, so it is not for all beers, nor for all people. The "best" method is the one which gives the desired result to the individual homebrewer.

    A final note about dry-hopping: the volatile hop compounds will react quickly with oxygen. For this reason, extra measures should be taken to avoid mixing with air during bottling or kegging, in order to retain the hop aroma for extended periods of time. These extra measures may include purging the bottling vessel and keg with CO2, very quiet siphoning, oxygen scavenging caps, and possibly delayed capping after bottling. This method allows any CO2 coming out of solution during the bottling process to push the oxygen out of the bottle before the caps are secured. This method is used by many homebrewers but, as always, the results are inconclusive. The simplest method is to use the oxygen scavenging caps, which requires no extra effort and little extra cost. For further reference, the Summer 1993 "Zymurgy" contains an article by Mark Garetz on this subject.

    What is a "Hop-back"?

    A homebrewer's hop-back is a reservoir connected in-line between the kettle and counter-flow chiller. It is filled with fresh hops before the flow is started. The hot wort flows through the fresh hops and is quickly chilled by the counter-flow before entering the fermenter. Many of the volatile hop aroma compounds are extracted and brought into the fermenter with this process. It is generally thought to produce a flavor/aroma profile somewhere between late kettle additions and dry-hopping. A good article by Kinney Baughman on building a hop-back is in the "Zymurgy" Gadgets and Equipment Special Issue, and another, written by Charlie Stackhouse, is in the Fall 1994 "Zymurgy" edition.

    Wet vs. Dried Hops?

    Yes, you can but at best it is a rough guess as to how much. The rule of thumb is to use 6 times as much (by weight) as you would dry hops. A safer rule would be to do this and to only use them for finish/dry hopping. Since these hops have not been tested, the AA% is unknown, and later additions are less sensitive to AA%. It should be noted that some homebrewers have had mixed results when using fresh hops (poor AA approximation for bittering, sometimes grassy aroma for finishing).

    High Alpha vs. Low Alpha

    Will high alpha acid hops contribute the same type of bitterness as low alpha acid hops? The short answer is: probably not. The longer answer has to do with the oils and resins in the hops. As previously stated, hops bring much more to beer than bittering. There are different qualities of bittering and many respected brewers agree that a cleaner, smoother bitter can be attained by using an equal number of IBUs from a low alpha hop. To quote George Fix: "I have always had a strong preference for low alpha aroma hops, even for early additions for bittering. I find that they give (if fresh!) a clean and mellow bitter, which contrasts with the crude effects I pick up from high alphas." According to Fix, Narziss et al cited the ratio of the hop oils alpha-humulene/myrcene as providing a refined flavor, with higher ratios (> 1.5) providing a positive effect. Fix followed this up with research on the hop resins, and showed that hops with < 30% cohumulone (as a percent of alpha acids) were preferred. The correlation between the two (oils vs. resins) has not been shown, but as in all areas where human perception is involved, proof is difficult. The bottom line: bitterness is not all the same.

    Hop Varieties and How to Use Them

    DISCLAIMER: Hop substitutes should generally be thought of as "last resort" options. Some of them work better than others, and of course, the individual brewer must decide which substitutes are best. No attempt was made here to label "good" and "not-so-good" substitutes, because the opinions vary wildly.

    Aroma Hops

    The following hops are generally considered aroma hops although in recent years they have started to gain a following in the homebrew community for bittering as well:

    Name:         CASCADE
    Grown:        US
    Profile:      strong spicy, floral, citrus (especially grapefruit) aroma
    Typical use:  bittering, finishing, dry hopping for American style ales
    Example:      Sierra Nevada Pale Ale, Anchor Liberty Ale & Old Foghorn
    AA Range:     4.5 - 8%
    Substitute:   Centennial
    Name:         CHALLENGER
    Grown:        UK (Northern Brewer heritage)
    Profile:      spicy aroma, fruity flavor
    Typical use:  dual purpose, aroma and bittering, blends well with other hops
    Example:      ???
    AA Range:     6.5 - 8.5%
    Substitute:   ???
    Name:         CRYSTAL (CFJ-HALLERTAU)
    Grown:        US
    Profile:      mild, pleasant, slightly spicy
    Typical use:  aroma/finishing/flavoring
    Example:      ???
    AA Range:     2 - 5%
    Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Mount Hood,
    Name:         EAST KENT GOLDINGS
    Grown:        UK
    Profile:      spicy/floral, earthy, rounded, very mild aroma;
                  spicy (candy-like?) flavor
    Typical use:  bittering, finishing, dry hopping for British ales
    Example:      Samuel Smith's Pale Ale, Fuller's ESB
    AA Range:     4.5 - 7%
    Substitute:   BC Goldings, Target
    Name:         ULTRA (was EXPERIMENTAL 21484)
    Grown:        US
    Profile:      fine aroma hop
    Typical use:  finishing for German style lagers
    Example:      None
    AA Range:     3 - 6%
    Substitute:   Hallertauer Mittelfrueh
    Name:         FUGGLES
    Grown:        UK, US, and other areas
    Profile:      mild, soft, grassy, floral aroma
    Typical use:  finishing / dry hopping for all ales, dark lagers
    Example:      Samuel Smith's Pale Ale, Old Peculier, Thomas Hardy's Ale
    AA Range:     3.5 - 5.5%
    Substitute:   East Kent Goldings, Willamette
    Grown:        Germany
    Profile:      pleasant, spicy/mild, noble, earthy aroma
    Typical use:  finishing for German style lagers
    Example:      Wheathook Wheaten Ale
    AA Range:     2.5 - 5%
    Substitute:   Hallertauer Mittelfrueh, Mt. Hood, Liberty, Crystal,
                  NZ Hallertau Aroma
    Grown:        Germany
    Profile:      pleasant, spicy, noble, mild herbal aroma
    Typical use:  finishing for German style lagers
    Example:      Sam Adams Boston Lager, Sam Adams Boston Lightship
    AA Range:     3 - 5%
    Substitute:   Hallertauer Hersbrucker, Mt. Hood, Liberty, Crystal,
                  NZ Hallertau Aroma
    Name:         LIBERTY
    Grown:        US
    Profile:      fine, very mild aroma
    Typical use:  finishing for German style lagers
    Example:      Pete's Wicked Lager
    AA Range:     2.5 - 5%
    Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Mt. Hood,
    Name:         LUBLIN
    Grown:        Poland
    Profile:      Reported to be a substitute for noble varieties, in fact is
                  said to be Saaz grown in Poland.
    Typical use:  aroma/finishing
    Example:      ???
    AA Range:     2 - 4%
    Substitute:   Saaz, Hallertauer Mittelfrueh, Hallertauer Hersbrucker,
                  Tettnang, Mount Hood, Liberty, Crystal.
    Name:         MT. HOOD
    Grown:        US
    Profile:      mild, clean aroma
    Typical use:  finishing for German style lagers
    Example:      Anderson Valley High Rollers Wheat Beer, Portland Ale
    AA Range:     3.5 - 8%
    Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Liberty,
    Name:         NZ HALLERTAU AROMA (an organic version also exists)
    Grown:        New Zealand
    Profile:      Said to be a replica of German Hallertauer Mittelfrueh
    Typical use:  fine aroma hopping
    Example:      Coors, Coors Light
    AA Range:     6 - 8%
    Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker, Tettnang,
    Name:         PROGRESS
    Grown:        UK (Whitbred Goldings heritage)
    Profile:      similar to Fuggles, but slightly sweeter
    Typical use:  bittering and aroma for British ales
    Example:      ???
    AA Range:     5.0 - 7.5%
    Substitute:   Fuggles
    Name:         SAAZ
    Grown:        Czechoslovakia
    Profile:      delicate, mild, floral aroma
    Typical use:  finishing for Bohemian style lagers
    Example:      Pilsener Urquell
    AA Range:     2 - 5%
    Substitute:   Tettnang (many would claim there is NO substitute)
    Name:         SPALT
    Grown:        Germany/US
    Profile:      mild, pleasant, slightly spicy
    Typical use:  aroma/finishing/flavoring, some bittering
    Example:      Common in Dusseldorf Altbiers
    AA Range:     3 - 6%
    Substitute:   Saaz, Tettnang
    Name:         STRISSELSPALT
    Grown:        France -- Alsace area
    Profile:      medium intensity, pleasant, similar to Hersbrucker
    Typical use:  aroma/finishing
    Example:      ???
    AA Range:     3 - 5%
    Substitute:   Hersbrucker, German Spalt
    Name:         STYRIAN GOLDINGS
    Grown:        Yugoslavia (seedless Fuggles grown in Yugoslavia),
                  also grown in US
    Profile:      similar to Fuggles
    Typical use:  bittering/finishing/dry hopping for a wide variety of beers,
                  popular in Europe, especially UK
    Example:      Ind Coope's Burton Ale, Timothy Taylor's Landlord
    AA Range:     4.5 - 7
    Substitute:   Fuggles, Willamette
    Name:         TETTNANG
    Grown:        Germany, US
    Profile:      fine, spicy aroma
    Typical use:  finishing for German style beers
    Example:      Gulpener Pilsener, Sam Adams Octoberfest, Anderson Valley ESB
    AA Range:     3 - 6%
    Substitute:   Saaz, Spalt
    Name:         WILLAMETTE
    Grown:        US
    Profile:      mild, spicy, grassy, floral aroma
    Typical use:  finishing and dry hopping for American / British ales
    Example:      Sierra Nevada Porter, Ballard Bitter, Anderson Valley Boont Amber
    AA Range:     4 - 7%
    Substitute:   Fuggles

    Bittering Hops

    The following hops are generally considered bittering hops, but some aroma applications have been noted (note that the examples given may not enlighten the taster as much as the aroma hops in the previous section):

    Name:         BREWER'S GOLD
    Grown:        UK, US
    Profile:      poor aroma;
                  sharp bittering hop
    Typical use:  bittering for ales
    Example:      Pete's Wicked Ale
    AA Range:     8 - 9%
    Substitute:   Bullion
    Name:         BULLION
    Grown:        UK (maybe discontinued), US
    Profile:      poor aroma;
                  sharp bittering and blackcurrant flavor when used in the boil
    Typical use:  bittering hop for British ales, perhaps some finishing
    Example:      ??? (Guinness Extra Stout and SSWW - not confirmed)
    AA Range:     8 - 11%
    Substitute:   Brewer's Gold, Pacific Gem
    Name:         CENTENNIAL
    Grown:        US
    Profile:      spicy, floral, citrus aroma;
                  clean bittering hop (Super Cascade?)
    Typical use:  general purpose bittering, aroma, some dry hopping
    Example:      Sierra Nevada Celebration Ale, Sierra Nevada Bigfoot Ale
    AA Range:     9 - 11.5%
    Substitute:   Cascade
    Name:         CHINOOK
    Grown:        US
    Profile:      heavy spicy aroma;
                  strong versatile bittering hop
    Typical use:  bittering
    Example:      Sierra Nevada Celebration Ale, Sierra Nevada Stout
    AA Range:     12 - 14%
    Substitute:   Galena, Eroica, Nugget, Bullion
    Name:         CLUSTER
    Grown:        US, Australia
    Profile:      poor, sharp aroma;
                  sharp bittering hop
    Typical use:  general purpose bittering (Aussie version used as finishing hop)
    Example:      Winterhook Christmas Ale
    AA Range:     5.5 - 8.5%
    Substitute:   Galena, Cascade, Eroica
    Name:         EROICA
    Grown:        US
    Profile:      clean bittering hop
    Typical use:  general purpose bittering
    Example:      Ballard Bitter, Blackhook Porter, Anderson Valley Boont Amber
    AA Range:     12 - 14%
    Substitute:   Northern Brewer, Galena
    Name:         GALENA
    Grown:        US
    Profile:      strong, clean bittering hop
    Typical use:  general purpose bittering
    Example:      Catamount Porter, Devil's Mountain Railroad Ale
    AA Range:     12 - 14%
    Substitute:   Northern Brewer, Eroica, Cluster
    Name:         NORTHERN BREWER
    Grown:        UK, US, Germany (called Hallertauer NB), and other areas
                  (growing region affects profile greatly)
    Profile:      fine, fragrant aroma;
                  dry, clean bittering hop
    Typical use:  bittering and finishing for a wide variety of beers
    Example:      Old Peculier(bittering), Anchor Liberty(bittering),
                  Anchor Steam(bittering, flavoring, aroma)
    AA Range:     7 - 10%
    Substitute:   Hallertauer Mittelfrueh, Hallertauer Hersbrucker
    Name:         NUGGET
    Grown:        US
    Profile:      heavy, spicy, herbal aroma;
                  strong bittering hop
    Typical use:  strong bittering, some aroma uses
    Example:      Sierra Nevada Porter & Bigfoot Ale, Anderson Valley ESB
    AA Range:     12 - 14%
    Substitute:   Chinook
    Name:         PERLE
    Grown:        Germany, US
    Profile:      pleasant aroma;
                  slightly spicy, almost minty bittering hop
    Typical use:  general purpose bittering for all lagers except pilsener
    Example:      Sierra Nevada Pale Ale, Summerfest, and Pale Bock
    AA Range:     7 - 9.5%
    Substitute:   Hallertauer Mittelfrueh, NZ Hallertau Aroma
    Name:         PRIDE OF RINGWOOD
    Grown:        Australia
    Profile:      citric aroma;
                  clean bittering hop
    Typical use:  general purpose bittering
    Example:      Foster's Lager, Victoria Bitter, Coopers Sparkling Ale
    AA Range:     9 - 11%
    Substitute:   ???

    Hard to Find Hops

    The following hops are relatively rare. In fact, they are rare enough that I haven't found much useful information on them, but they are included here for completeness.

    Name:         GREEN BULLET
    Grown:        New Zealand
    Profile:      ???
    Typical use:  Bittering and aroma in lagers, even pilseners
    Example:      ???
    AA Range:     8 - 12%
    Substitute:   Styrian Goldings
    Name:         NORTHDOWN
    Grown:        Ireland
    Profile:      good flavor and aroma, blends well with other UK types
    Typical use:  all purpose ale hop
    Example:      Guinness
    AA Range:     7.2 - 9%
    Substitute:   Target, Northern Brewer
    Name:         PACIFIC GEM
    Grown:        New Zealand
    Profile:      delicate black currant/floral nose
    Typical use:  Strong Bittering, but also some aroma applications
    Example:      ???
    AA Range:     14%+
    Substitute:   Bullion?
    Name:         SOUTHERN CROSS
    Grown:        New Zealand
    Profile:      ???
    Typical use:  Strong Bittering and fine aroma qualities
    Example:      ???
    AA Range:     11-12%
    Substitute:   ???
    Name:         STICKLEBRACT
    Grown:        New Zealand
    Profile:      Said to be comparable to European Northern Brewer
    Typical use:  Strong Bittering as well as aroma uses
    Example:      ???
    AA Range:     11 - 13%
    Substitute:   Northern Brewer
    Name:         SUPER ALPHA
    Grown:        New Zealand
    Profile:      ???
    Typical use:  bittering and aroma applications
    Example:      Steinlager, Hahn Premium
    AA Range:     10 - 13%
    Substitute:   ???
    Name:         TARGET
    Grown:        UK
    Profile:      accounts for 40% of UK hop production
    Typical use:  mostly used for bittering, some aroma potential
    Example:      Young's Special London Ale
    AA Range:     10.5 - 12.5%
    Substitute:   Northdown, Progress


    Glenn Anderson (
    Scott Barrett (adiron!!scott@uunet.UU.NET)
    Jeremy Bergsman (jeremybb@leland.Stanford.EDU)
    Jim Busch (
    Nick Cuccia (
    John DeCarlo (
    David Draper (
    Alan Edwards (
    George Fix (
    Bill Flowers (
    Jeff Frane (
    Mark Garetz (
    Russ Gelinas (
    Mark Kellums (
    Al Korzonas (
    Rick Larson (
    Don Leonard (
    John Palmer (
    Bob Regent (
    Peter Soper (not online?)
    Spencer Thomas (
    Glenn Tinseth (gtinseth (at) yahoo (dot) com)
    Rich Webb (
    Patrick Weix (
    Carl West (eisen@kopf.HQ.Ileaf.COM)
    Ed Westemeier (
    Dave Wiley (
    Gene Zimmerman (EZIMMERM@UWYO.EDU)

    Business catalogs referenced

    Just Hops--Mount Zion IL
    HopTech--Danville, CA
    Hopunion USA--Yakima, WA

    Further Reading

    Kinney Baughman
  • "Zymurgy" Gadgets and Equipment Special Issue, 1992
  • David R. Beach
  • Homegrown Hops
  • George Fix
  • "Science in the Service of the Brewer's Art", National Homebrewer's Conference Transcripts, 1994.
  • Mark Garetz
  • "Zymurgy" Summer 1993,
  • "Brewing Techniques" Jan/Feb 1994,
  • Using Hops, The Complete Guide to Hops for the Craft Brewer, 1994
  • "All About Bittering", National Homebrewer's Conference Transcripts, 1994.
  • Alfred Haunold & Gail Nickerson
  • "Brewing Techniques" May/June 1993
  • Charlie Papazian
  • The New Complete Joy of Homebrewing
  • Dave Miller
  • The Complete Handbook of Homebrewing
  • Jackie Rager
  • "Zymurgy" Hops and Beer Special Issue, 1990
  • Pierre Rajotte
  • "Zymurgy" Hops and Beer Special Issue, 1990
  • Quentin B. Smith
  • "Zymurgy" Hops and Beer Special Issue, 1990
  • Charlie Stackhouse
  • "Zymurgy" Fall 1994
  • Glenn Tinseth
  • "Brewing Techniques" Jan/Feb 1994
  • Send feedback to: gtinseth (at) yahoo (dot) com