How do you calculate how much water you lose during the boil?

[biggrizzly]

How do you calculate how much water you lose during the boil?

Now that I got a new 10 gallon pot I want to figure out how to do full 5 gallon boils without adding too much water to the finished wort prior to pitching.

 

[dale1038]

Why would you add any water back with a ten gallon pot? Average is 1 gallon per hour. So boil 6 gallons to get a 5 gallon batch.

 

[dwarven_stout]

Fill it full of water and boil for an hour. Measure how much you have left, and work backwards.

 

[bessieflames]

You have to try it once. It varies based on equipment. It also varies based on how high the burner is. I lost 3 gallons per hour the first time, but I brought it down to 2 gallons an hour by lowering the flame.

 

[JonM]

+1 to the above. Might even want to do the whole chill too, because you'll lose a little bit more steam while chilling.

 

[BBL_Brewer]

+1 to the above. Might even want to do the whole chill too, because you'll lose a little bit more steam while chilling.

You don't lose any substantial volume to steam while chilling especially if your chilling method is efficient. You will however have a difference in volume due to temperature. When liquid cools it contracts and takes up less space.

 

[biggrizzly]

Thanks guys. If I did a dry run with just water and then chilled and measured would the loss be the same as if I were boiling wort? I just got a 10 gal boilermaker and a Blichmann burner to go with it for Christmas from the family and anxious to try it all out this Sunday.
Oh, I'm also using a 20ft coiled copper chiller.

 

[biggrizzly]

Why would you add any water back with a ten gallon pot? Average is 1 gallon per hour. So boil 6 gallons to get a 5 gallon batch.

That is the point of the question... I don't want to add back, so I want to figure out how much to start with.

 

[Sea]

Thanks guys. If I did a dry run with just water and then chilled and measured would the loss be the same as if I were boiling wort? I just got a 10 gal boilermaker and a Blichmann burner to go with it for Christmas from the family and anxious to try it all out this Sunday.
Oh, I'm also using a 20ft coiled copper chiller.

It will be close enough to work just fine. The exact amount you lose will vary a little simply because you can't set your burner exactly the same every time. You just need to get close. I typically lose about 1.25 gal/hour, but you might have a slightly different result.

 

[brtisbuck]

I have a question concerning this also. I am about to do my first full boil and was planning on only starting with 5.5 gallons and add because I don't want to end up with more than 5 gal until I get the feel for it. Do you include your LME in that amount? Say I start with 5.5g and add 6# of LME I am closer to a total of 6g right?

 

[Kuhndog]

Can anyone chime in on Brtisbuck's question because I'm wondering the same thing. I just got a brew kettle that I'll probably use for the 1st time this weekend or next weekend.

Thanks.

 

[ETCS]

I have a question concerning this also. I am about to do my first full boil and was planning on only starting with 5.5 gallons and add because I don't want to end up with more than 5 gal until I get the feel for it. Do you include your LME in that amount? Say I start with 5.5g and add 6# of LME I am closer to a total of 6g right?

5.5 is not enough pre-boil volume. Like posted above average is about 1
gallons per hour, so with after a 60 minute boil you'd end with 4.5 to 5 gallons in the fermenter. Each system is different. My system is about 1.5 per hour. so I always us a pre boil volume 7 gallons, and end up with 5.5. After trub loss, etc...I end up with 5 gallons in the fermenter.
Also, if you aren't close enough to your post boil volume, boil longer than 60 minutes until you get there. That is another thing I like about AG, is that I don't have to add any top off water. Cheers

 

[brtisbuck]

Can anyone chime in on Brtisbuck's question because I'm wondering the same thing. I just got a brew kettle that I'll probably use for the 1st time this weekend or next weekend.

Thanks.

I will answer my own question. I brewed Sunday. Decided to start with 5.5 gallons in a 36qt square squatty aluminum kettle. Added 2/3 of my 6# LME in the last 5 min of a 60 minute boil. I had to add just over .5 gal to my carboy to be at exactly 5 gal. after the boil.

Next brew I will start with 6 gallons of water + extract and probably leave it at that if I'm close. While I'm new, I would rather add just a little than end up way over. FYI my kit og was 1.044 and I tested at 1.045 give or take temp correction errors.