Preboil Volumes

[FireRescueFL]

Doing my first AG tomorrow, also first full boil. How many gallons do you typically start with for a 60 min boil to end up with 5 gallons? Rough estimate to get me headed in the right direction is fine. Thanks!

---Chris

 

[Tall_Yotie]

As many will say, depends on your altitude and how strong a boil you are having (stove or propane burner?). I tend to collect 6 to 6 1/2 gallons for a boil.

I would aim for 6 1/2 gallons. Means more water to sparge with, and you can give it a stronger boil if you need to.

Remember, if you are using Pilsner grain, you want a 90min boil. And if you happen to boil off more water than you were expecting you can always add some more afterwords.

 

[Brewerforlife]

Always remember when you measure volume at close to boil temp. it will be 4% less when cooled to 65-70F due to expansion/contraction between the 2 temperature extremes. Hope this helps!! Cheers!!!

 

[1MadScientist]

In my NB 10 gallon MegaPot with a 17" diameter, in Florida I lose 2 gallons + during my 1 hour boil, it's 7 1/2 gallons in pot for me.

 

[lylo]

My 16"BK loses 7Liters/hr to evaporation

 

[Brewerforlife]

I didn't mean evaporation, that should average 5-15%/hr. I am saying, if you take a pot of water, lets say we measure 6 gals. of 210F water, then cool it to 68F without ever boiling it. there will be 4% less volume because the original 210F measure was at its expanded state. So your almost 1 quart less without even boiling yet. Cheers!!!

 

[Willum]

Doing my first AG tomorrow, also first full boil. How many gallons do you typically start with for a 60 min boil to end up with 5 gallons? Rough estimate to get me headed in the right direction is fine. Thanks!

---Chris

I have a wide 8 gallon pot which fits over two burners on my kitchen stove. I loose over 2 gallons during the boil. I guess it is because I have both burners at full blast, but this is the only way I can achieve a rolling boil. My first all grain batch ended up at 4.5 gallons into the primary and I was was aiming for 5.5. I guess I am saying that results will vary based on equipment and so on. :cross:

 

[Brewerforlife]

Commercial boil-off rates are closer to 5-10&/hr, even with steam. Your getting 25% thats a tad high. I would assume you would have one hell of a rolling boil to get 25%. Is this in a 1 hour boil?? I think for home brewers its so easy to have a high btu/hr to volume ratio compared to large commercial direct-fired kettles. I have a 250,000 btu burner for my 240 gal. kettle, and get full, hard rolling boils that i have to even cut-back the gas to not have a boil-over, but still only get about 5-7%/hr boil-off rate. Most commercial systems require a minumum of 1000btu/hr per gal. in kettle size. I'm amazed you can't fanagle the two burners to have a good hard boil without loosing 25%. You may get some increased maillard reactions with 25% , which would darken wort more and may increase it's caramel tones, which would be good in some styles, like bock,doppelbock,scotch,etc. Is this electric or gas, if so how many btu/hr burners do you have? Hope this helps!! Cheers!!!

 

[JRL]

I usually start with 6.5 - 7 gallons and end up with 5 to six gallons from a 60 min boil. Works well for me

 

[Willum]

Commercial boil-off rates are closer to 5-10&/hr, even with steam. Your getting 25% thats a tad high. I would assume you would have one hell of a rolling boil to get 25%. Is this in a 1 hour boil?? I think for home brewers its so easy to have a high btu/hr to volume ratio compared to large commercial direct-fired kettles. I have a 250,000 btu burner for my 240 gal. kettle, and get full, hard rolling boils that i have to even cut-back the gas to not have a boil-over, but still only get about 5-7%/hr boil-off rate. Most commercial systems require a minumum of 1000btu/hr per gal. in kettle size. I'm amazed you can't fanagle the two burners to have a good hard boil without loosing 25%. You may get some increased maillard reactions with 25% , which would darken wort more and may increase it's caramel tones, which would be good in some styles, like bock,doppelbock,scotch,etc. Is this electric or gas, if so how many btu/hr burners do you have? Hope this helps!! Cheers!!!

It is a gas stove. The only thing I can think of is that it takes what seems like forever to get to a boil.