Just finished bottling up my first (half) batch of IPA, recipe and ingredients through Brewer’s Best. At boil three weeks ago, we started with 2.5 gallons of water and halved all of the ingredients. When we transferred from the kettle to the primary, we did not add any more water. It went into a primary fermenter, pulled the brew off the trub into a secondary, and took it back into a bottling bucket where today, we ended with 12.5 twelve ounce beers. That’s 1.17 gallons.
Where did all my beer go?
We were not being overly-conservative when transferring from the kettle, to the secondary, or even to the bottling bucket. We took the approach of “it’s okay to have a little sediment in each stage, it will fall out during the next.” We knew to account for some volume loss in the trub of the primary and secondary, but certainly not 1.33 gallons worth.
I might be new to brewing, but I am not new to measuring.
I had a friend remind me that I should have added a half gallon of water to the primary to bring it up to the full half-batch capacity.
But still. I had 2 gallons. Attributing .25-.5 gallons to the trub and yeast cake, there’s still some margin of mysterious disappearance.
90% of the time I only have an idea on what the volume is in the fermenter. I have markers every half gallon, but if it’s between the mark I am simply guessing. I also use better bottles and with the ribbing it’s worse.
Just try again, start with a larger volume pre-boil, measure carefully, measure your OG and see if it’s in range. 1 gallon boil of is a good starting point, and if you are brewing extract you should have a solid idea what the OG should be.
Measure off your fermenter .5 gallon at a time and mark it. Sharpie tends to wear off so a little packing tape on the marks will help. You will loose some to the trub and yeast. I aim for about 5.5 gallons in the fermenter to account for loss. I also plan for .5 gallon loss in the kettle.
Also, secondary fermentation isn’t all that popular these days but under certain conditions. You can skip that step and save some loss there. You will find countless threads on here denouncing the use.
When I brew, the volume in the kettle at the end of the boil will shrink when cooled, the often stated number is 4%. That is .4 gallon on a 10 gallon batch, but only 0.08 on a 2 gallon batch. Not much at all, but it is some.
Part of the problem in sorting out your volume disappearance is not knowing any volume between pre-boil and what went into the bottles.
You definitely lose volume to evaporation during the boil. With a small boil volume you could be losing up to a gallon per hour. Add volume loss due to shrinkage as the wort cools, trub loss, whatever was left behind in the secondary and bottling bucket, and absorption by your dry hops. Could easily be more than a gallon of your batch.
Besides the trub and whatnot, some of your loss is probably captured in your bottles. Take a bottle and fill it with exactly 12 ounces of liquid. You’ll see that point is most likely lower than where you filled the bottles with beer.
Pretty sure steve wasn’t taking a shot here. I know personally that I rarely if ever take a really accurate measurement in my brewery. it’s almost always ‘more or less’.
you say 2 gallons went into primary. if you left .5 behind in trub that’s 1.5 gallons into secondary, now you said you had some trub carryover to secondary so you likely lost another say .2 gallons there and as mdixon points out it’s unlikely that each bottle has exactly 12 floz in there.
Here’s a cool theory that might account for part of it as well, courtesy of Bill Nye:
if you mix 1 cup of water and 1 cup of 99% alcohol you do not end up with 2 cups of liquid. some of the water will actually slip between the molecules of alcohol and the total volume with be lower than the theoretical sum of the parts. I have no idea if there is enough of this effect in beer to make up even an ounce of your loss but with at 49.5% ABV it’s a couple ounces loss out of 8+8 ounces.
Jonathan, thats a really neat thought from Bill Nye. I had never thought about my beers that way. like you said, its probably not a large noticeable difference, but I have had my own doubts about my volume losses along the way.
Also, the OP brewed an IPA. The hop particles likely thickened the layer of gunk on the bottom of the fermenter more than for most other beers,ie. slightly less yield, aside from the previously mentioned factors which contributed.