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Water Volumes for BIAB


Sep 4, 2017
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So I use beersmith 3 for BIAB brewing, one thing I have noticed is that is always asks for about 4 litres (1 gallon) more water into the pot than makes sense.  I start with 7.5 gallons of water for a 5 gallon batch and end up with 1 to 2 litres extra after filling the keg, close enough.  If I follow the beersmith volume I would easily end up with more than a gallon extra.  Is there away to change this?


Grandmaster Brewer
Oct 5, 2016
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Bay Area, California
You need to set up your profiles to reflect the equipment and process you have. The BeerSnith defaults are just guidelines or guesses. There are several things that affect the amount of water needed:

1) Grain absorption. This is set in Options -> Advanced and has "grain absorption" and "BIAB grain absorption". Carefully measure the volume of starting water and wort remaining after you remove your bag of grains to make sure this setting is correct for your grain crush and setup. If the absorption number is higher than your actual absorption you will be instructed by BeerSmith to add more starting water than you need.

2) Boiloff rate. This is set in the equipment profile. Carefully measure your volume before and after a 1-hour boil and enter that number here. If your actual boiloff is less than the number in your profile you will end up with extra liquid. You can do a test boil with water to measure this.

3) Loss to trub and chiller. This is also set in the equipment profile. If your actual loss is less than the number in the profile then you will end up with too much liquid.

There are some videos on how to set up equipment profiles. I don't have the links, but if you do some searching you should be able to find them. Once you have profiles that accurately reflect your equipment and process you should get better results from BeerSmith.



Grandmaster Brewer
Apr 7, 2017
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GigaFemto is spot on. You must customize your equipment profile. Even if you see a profile already included in the software that matches your own - your use of that same setup will be different enough as to get different results.

Here are two equipment profile setup tutorials:



Setting custom mash profiles is also a good idea. Here is one for BIAB"