Sparge Gravity

[neldor19]

When sparging,when is the best time to stop?I know I need about 7 gallons but Mr.Palmer says to stop the run-off at .008 to avoid raising the ph and extracting tannins.Do I stop at .008 and and add water to bring up my volume if Im short?Would 5.2 stabilizer help this situation?


Thanks!:)

[haaseg]

I tried this once, and it seems to be a problem. I'm assuming that by quoting palmer, you are doing fly sparging. In this case, any time you let the water level get below the top of the grain bed, you're going to be in trouble. The grains are a bit suspended, and when the water drains out, they tend to compact.

I tried to put more water in after the fact, and all I got out the bottom was a bunch of husks and grain particles. I tried to recirculate several quarts, but it just never cleaned up. The beer turned out fine anyway... actually it's quite good.

Given that, I've resolved to try the following: As soon as the sparge tank is empty, but while there's still at least an inch of water over the grain bed, I'm going to drain enough for a measurement and shut off the valves immediately. Hopefully that will keep the grain from impacting long enough to heat up more sparge water.

But I usually put in more sparge water than I need, and the output is running very clear long before the tank is empty. You can always boil it off... I'd rather have too much than not enough. You want to wash all those converted grains out.

[neldor19]

Yes,I am fly sparging.Actually I meant should I stop my sparge at .008 regardless of how much wort was collected and just add boiled water to the wort,not the mash,to bring up to 7 gallons for the boil.
Sorry for not being clear on that:D

[HogieWan]

How are you checking your gravity during the sparge?

[neldor19]

Im just taking a sample from the run offcoming from the tun,using a hydrometer/test jar.Im not taking a reading from the collected wort itself.

[HogieWan]

A hydrometer is only accurate at 60* fahrenheit. Are you cooling your sample first? Otherwise your reading will be way too low.
If you want to see the difference, test your cold tap water and then test your hot tap water - same gravity, just different tempetures. I think you'd be surprised.

[neldor19]

Yep,cool it down to 59/60 before I take my reading

[BrewDog]

I've dropped and broken too many hydrometers. Now I use a refractometer. 2-3 drops of liquid is enough to measure. Much faster and more accurate (be sure to use in conjunction with Promash for FG readings). I think mine cost $50 or $60 online. Worth every penny.

[HogieWan]

refractometer - that's my next purchase.

[haaseg]

There are few charts out there that give conversion factors for using the hydrometer at different temperatures. At typical sparge water temperature, I think you add like .012 or something. I found that out after measuring the gravity and coming out far below 1.000.

You should calibrate your hydrometer by measuring water at 60 degrees to get your base offset. Also measure it in water at specific temperatures you will be measuring your wort at. If you measure the water at 170 and it comes out 0.984 (-0.016), then you will need to 0.016 to your measurement to get your actual gravity... e.g. if you measured 0.990 then your actual gravity would be 1.006 ( 0.990 + 0.016).

Of course, it's relatively easy to calibrate your hydrometer to this temperature... I just float mine in the sparge tank with the sparge water.

[neldor19]

Thank you for the hydrometer info...good stuff.But as to my question,what Im asking is..........well lets put it this way.Im sparging and I have collected 6 gallons of wort and I need 7.My run-off readings are at .008.Ive read that if your mash/run-off drops to below .008,then the ph will rise resulting in tannin extraction of the grain husks.Do you guys usually stop at a certain gravity reading and just add 1 more gallon of water to the 7 gallons for the boil or do you just keep on sparging till you get what you need regardless of the gravity of the run-off?Ive only done a few AG's,and I know I had a problem with my efficiancy.Is 7 gallons alot to ask from a 7 to 8 pound grain bill?
Other then effecting my hop utilizations,just adding that extra water after I hit .008 shouldnt hurt anything since itll just boil off anyway right?

[HogieWan]

yes - add extra "make up" water. Don't sparge any more or you'll get off flavors in your beer.

[Grog]

Well, it depends on the gravity of the wort already collected in the kettle. If you are at your target gravity (for beginning of boil) with 6 gallons and you add another gallon of top up water, you will end up with a thinner/weaker beer because you have diluted it by 15%. I favor intended gravity over intended volume. Best to take the smaller volume this time and add more grain next time.

I personally build in a huge margin of error and the lowest runnings I have ever collected were 1.020.

[neldor19]

Ya Im thinkin its just my lack of experiance talkin here,hehe.Im sure once I get the bugs worked out of my system and get a consistant efficiency Itll be less of a problem.I just rebuilt my mash/lauter tun cause I was getting really crappy efficiency and I realized I screwed up on the manifold design.And ya,once I get a consistant efficiency nailed down,Ill just make adjustments if needed using extra grain.
Thanks alot guys,youve been much help:D