Easiest AG question everrr

I'm an AG noob and I'm wondering - if my batch size is 5 gallons, my boil volume should be what? 6.25 or 6.5 gallons? I've never done a full boil in the past...

Right. Have enough wort collected so that after your 60 minute boil you have about 5.5 G to go into the bucket or carboy. - Dirk

It depends on your evaporation rate and your boil time, but in general 6.5 for an hour boil will get you 5.5 gals. 5.5 is a nice amout to ferment so you end up with 5 by the end.

How would I know my evaporation rate? The boils will be 60 minutes. I'd like to end up with 5.5g going into the fermenter. That should cover absorption and samples...

Just measure your volume before and after the boil, there's not really any way to figure it out before hand. I think the average is about 1 gallon per hour though.

jacob's right...you'll only know your evaporation through trial and error.

my burner is a little too powerful...I tend to lose more than 1 gallon in an hour boil.

Thanks guys. I'm gonna start with 6.5 gallons and see what I'm down to. Live & learn

soulive, you could always try a sample boil with just water to get a better idea. This would pretty much nail it down for you.

stale said:

soulive, you could always try a sample boil with just water to get a better idea. This would pretty much nail it down for you.

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Great point. That's what I'll do

I'm usually at 7-7.25 gallons to get between 5 and 5.5.

And I have a crappy burner.

I just lose a lot it seems.

There are so many variables to go into it, such as your location, the conditions that day, how hot you run your burner, your kettle size and configuration, and that always present x-factor. In time, you'll get a good feel for it.

Welcome to the fun of homebrewing!


TL

Do you have any brewing software? You just need to do a few batches and back-calculate your evap rate.

Personally, I go with 1.25 quarts per pound of grain for my mash, and then 1/2 gallon per pound for my sparge. That ends up all over the place, so I usually adjust my boil time rather than my water volumes.

Evan! said:

Do you have any brewing software? You just need to do a few batches and back-calculate your evap rate.

Personally, I go with 1.25 quarts per pound of grain for my mash, and then 1/2 gallon per pound for my sparge. That ends up all over the place, so I usually adjust my boil time rather than my water volumes.

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I use Beersmith currently. I usually use 1.25 also for my mash. I sparge with whatever amount Beersmith says. In the past I've partial-mashed and to get 3 gallons I started with about 4.25 boil. I don't know the physics of it, but I'm guessing I should start with 6.75 boil if I wanna end up with 5.5 total. The only thing that worries me with changing boil times is the IBUs...

Yeah, you know I never put together the fact that you wanted to buy my 30qt kettle to move up to all grain but I've got to do the right thing and tell you that 30qts really isn't quite enough for 5.5 gallon finished batches. You'll probably want to collect from 6.5 to 7 gallons and a half gallon of headspace in the kettle is just asking for boilovers. Someone just posted a thread about 40qt aluminum pots on ebay for $39 shipped. That's where you want to be. I craft recipes to 5.75 or even 6g in the fermenter so that my kegs are filled after trub loss and samples.

Bobby_M said:

Yeah, you know I never put together the fact that you wanted to buy my 30qt kettle to move up to all grain but I've got to do the right thing and tell you that 30qts really isn't quite enough for 5.5 gallon finished batches. You'll probably want to collect from 6.5 to 7 gallons and a half gallon of headspace in the kettle is just asking for boilovers. Someone just posted a thread about 40qt aluminum pots on ebay for $39 shipped. That's where you want to be. I craft recipes to 5.75 or even 6g in the fermenter so that my kegs are filled after trub loss and samples.

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No worries, I've been brewing in a 20qt pot with boil sizes of 16qt. I should be able to handle the 1 gallon headspace. If not, I'll go with a boil size of 6 gallons...

Soulive21 said:

No worries, I've been brewing in a 20qt pot with boil sizes of 16qt. I should be able to handle the 1 gallon headspace. If not, I'll go with a boil size of 6 gallons...

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I usually collect 7.0 gal in my 7.5 gal s/s kettle. Then, I just boil VERY carefully for the first 30 minutes, then once I'm down to about 6.5 gal, I crank the heat a little further so I can get a good hot break boil going.

FWIW, I almost always do either 90" boil or 105" boil (in other words, 1:30 or 1:45)

As long as you haven't added your aroma hops, though, and you STILL have too much liquid near the end of boil, just keep boiling for an extra 10 minutes.

chriso said:

As long as you haven't added your aroma hops, though, and you STILL have too much liquid near the end of boil, just keep boiling for an extra 10 minutes.

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How about the flip side. If I've boiled away too much, can I just top up with water? Assuming it's okay (and I don't see why it wouldn't be but of course that's why I'm asking), should I do it during the boil, or can I add it to the fermentor the same as when I top up my extract brews?

If you are going to top up, do it in the boil for sanitary reasons. really either will work for you though.

I've heard Jamil say that his ideal evaporation rate is 12% per hour and that anything over 15% is too much (that's with an ideal pot that is as wide as it is tall). That means that for a five-gallon batch, only 0.7 gallons should be evaporated. This seems way lower than anyone on this site reports. Comments?

mew said:

I've heard Jamil say that his ideal evaporation rate is 12% per hour and that anything over 15% is too much (that's with an ideal pot that is as wide as it is tall). That means that for a five-gallon batch, only 0.7 gallons should be evaporated. This seems way lower than anyone on this site reports. Comments?

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I boil for more than an hour, so 90 minutes = .7 + .35 = 1.05, so my 6.75-7.00 boils down to 5.75-6.0. Then, add a TON for trub loss, because my kettle sucks, and you get 5.5

IowaStateFan said:

How about the flip side. If I've boiled away too much, can I just top up with water? Assuming it's okay (and I don't see why it wouldn't be but of course that's why I'm asking), should I do it during the boil, or can I add it to the fermentor the same as when I top up my extract brews?

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I don't know the answer to this question, sorry. My 2nd batch came in WAY under (~4.25 gal), and I just wound up with a small batch, rather than mess with it. I'm still working on this area.

You will lose some to trub, don't forgot... 1/2 gallonish. ... I made about 20 batches in a 30qt pot and it SUCKED. But it got the job done. Just had to constantly babysit the boil.. averaged around 3 boil overs per batch. God knows how much beer I lost to my sidewalk.

Here's a question. Is there anything wrong with collecting 6-6.5 gallons from you sparge and starting your boil and then getting another gallon or so and adding it later to the boil to compensate for a higher evaporation rate? I also boil with a 30 qt pot and my first all grain came it around 4.5 gallons when i was done. If I had extra runoff could I add that the last 15 minutes of the boil without screwing things up?

covered95 said:

Here's a question. Is there anything wrong with collecting 6-6.5 gallons from you sparge and starting your boil and then getting another gallon or so and adding it later to the boil to compensate for a higher evaporation rate?

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I think that your hops utilization will be off. I am not sure how you would calculate the correct amount of hops to get the desired IBUs . - Dirk

chriso said:

My 2nd batch came in WAY under (~4.25 gal), and I just wound up with a small batch, rather than mess with it. I'm still working on this area.

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My last batch came in at a bit over 4.5 gallons. I topped up because otherwise my O.G. would have been too high. The beer is in the secondary so I haven't had a chance to see the effects of doing that. It seems to me it should be okay because it's essentiall a concentrated boil like using extracts.

I'm still trying to dial in my system, but I lost a bit less than 2 gallons over 75 minutes on my last batch. I live up in the mountains and I'm not really surprised that I'd lose that much with the altitude and very dry air. Problem is I only have a 30qt brewpot. I'd like to go bigger, but my budget won't allow it right now.

Just gotta measure your setup. My all-electric can boil way more than 2 gallons off in an hour if i let it, just gotta learn your system!

~M~

During the hotter weather I would start with 7 gallons and then by the end I would have the correct amount after 60 minutes. Then I made a batch in cool and rainy weather and ended up with too much liquid. I think I had turned down the burner more than usual also.

You just have to learn what happens with your system.

This thread is very nearly 3 years old... I imagine the OP has figured out his boil off rate.

Buy/use a beer calculator like beersmith - it really helps you understand a lot of this stuff sooner.

In fact, I'm 99% sure the OP quit brewing over 2 years ago.

Bobby_M said:

In fact, I'm 99% sure the OP quit brewing over 2 years ago.

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Ha! Well, if he ever decides to go back into the fold, he'll have a wealth of info....