Extreme Boil Loss

[rohman]

I recently converted to all grain brewing from extract and I am now having boil loss issued. My system is a converted keg all electric RIMS with PID's that control the HLT heat exchanger and boil kettle. The problem is that when I set the boil kettle to say 220 degrees to boil I get a great rolling boil but I evaporate about 2 gal per hour. I have tried programming the PID to around 212-215 but each time the heating element cycles off my boil stops. Is it OK to have a boil that is intermittent?

[toneyc]

Just sparge a little more to get 7 gallons in the boil pot. As long as you're not getting too low on the runoff gravity, plan for boil off.

:)
Toney.

[rohman]

Toney thanks for the reply, I have been doing that but I would like to boil off less so that I can do 10 gal batches without boiling over.

[Mad Scientist]

First off, you need to post pictures and specifications of your system.

Second, how much volume are you collecting from your mash? I use converted keg, and I collect 7.5 gallon that is reduced to 5.5 to 5.25 after a 1 hour boil. I use a burner, but I usually have to throttle it back once a boil is achieved.

[rohman]

Originally posted by Boerne Brew
First off, you need to post pictures and specifications of your system.

Second, how much volume are you collecting from your mash? I use converted keg, and I collect 7.5 gallon that is reduced to 5.5 to 5.25 after a 1 hour boil. I use a burner, but I usually have to throttle it back once a boil is achieved.


My system is a converteg keg (1 for HLT 1 for BK and a 12 gallon square cooler for the MT) I will post pictures as soon as I get a chance.

After my first brew using this new system I collected about 6.5 gallons which I boiled down to 4.5. On my other 3 brews I have been collecting about 7.5-8.0 gallons and boiling down to 5.5-6.0. My issue is I have no way to "throttle back" by boil because I am using an all electric system (the element is on or its not). The only way I can reduce my evaporation rate is by cycling the element on and off; which in turn creates a boil that is vigourous when the element is on and not boiling when the element is off.

-Ryan

[HogieWan]

There may be a way to send less voltage to the heating element, thereby "throttling back" the heater.

The other thing to do is - collect as much wort as possible. If you have less than desired at the end of the boil, add some top up water at the end or one quart at a time throughout the boil.

[corkybstewart]

Be glad you have such a good rolling boil and just adjust your recipe to account for it. For my 10 gallon batches I collect about 13 gallons to have 10.5-11 when its all over. At least 1/2 gallon of that will be trub and hops. Then I know I'll lose another quart in the fermenter so I end up with around 10-10.5 gallons. Throw a little more grain, 1/2 pound, with every batch and use a little more sparge until you're comfortable with your setup and your results. All my recipes state "for 10 gallons" but in reality they're for 11 gallons and the amounts have been adjusted for the difference.

[Mill Rat]

I'd have to do a product search but you should be able to find an electronic control for your heating element that will pulse-width modulate (PWM) the power to reduce the power to the element. This is the same sort of control that is used for household incandescent light dimmer switches. These are usually limited to 600 or 1000 watts, which isn't enough to deliver a rolling boil in a brew kettle. Tying a modulated heating element into your control system will require a little engineering.

If you can get another pipe coupling welded into your kettle, you could use two heater elements of about half the wattage of the present one each. One can be on all the time to keep the boil going, and the other comes on only to bring it up to boil quicker.

[Mad Scientist]

We might go this way:

What brand PIDs are you using? Do they have a ramp & soak capability. Furthermore, what are your alarms set at? Also, are you using thermocouples or RTDs? If thermocouple, what type.

We may be able to adjust the PIDs, such that they go just a tad bit lower, and switch on & off, etc.....

[dparsons]

If you step up your batch size, you'll get less boil off on a percent basis. Same power = same quantity of water loss.

[Mad Scientist]

Originally posted by dparsons
Same power = same quantity of water loss.

I'l agrye less boil off with more volume, you have a larger thermal mass to heat.

[rohman]

Originally posted by Boerne Brew
We might go this way:

What brand PIDs are you using? Do they have a ramp & soak capability. Furthermore, what are your alarms set at? Also, are you using thermocouples or RTDs? If thermocouple, what type.


We may be able to adjust the PIDs, such that they go just a tad bit lower, and switch on & off, etc.....


I am using OMRON E5GN temperature controllers here is a link
http://omrwsc.am.omron.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&storeId=10001&productId=115573&langId=-1&categoryId=16836

I believe that they do have ramp and soak capability. Also I am using thermocouples which are stainless steel probes type J.

[Mad Scientist]

For this application, a type T thermocouple or an RTD would be better suited than a J type thermocouple. I'll look at your PID later.

Maybe millrat can join me in this?

[Mill Rat]

I'll comment when I've got a spare moment, right now I'm swamped at work, though. Your right, a T thermocouple would provide little more precision because it has a smaller range. They are a little harder to find and not as cheap as the type Js, though.

[Mad Scientist]

Yeah , but they are not super expensive either. TRD, I think would be the best. Their slow response time might be an advantage.

Now that I think about it, rohman, where is your thermocouple situated?

[rohman]

Originally posted by Boerne Brew
Yeah , but they are not super expensive either. TRD, I think would be the best. Their slow response time might be an advantage.

Now that I think about it, rohman, where is your thermocouple situated?

My thermocouple is located near the bottom (about 6" from the bottom of the kettle) at the same level as the heating element.