1 Gallon? 2 Gallon? 2.5 Gallon?

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Gary22

Well-Known Member
So, I'm a new brewer. A couple batches under my belt. I want to start getting into experimental brews or just test brews to see if I'd like something in a bigger batch. I also want to go a lil smaller to be able to drink more varieties of beers to get their flavor profiles. My questions are:

1) Approximately how much beer will 1 gallon brews, 2 gallon brews, and 2.5 gallon brews produce? (12oz./22oz. bottles)
2) If I wanted to do 1 gallon, 2 gallon, or 2.5 gallon brews, how much water would I have to start the boil with?
3) How much head space would I need in a carboy? (I guess what I really want to know here is what kind of primary/secondary fermenters I would need to be buy for each)
4) I know I can scale down all 5 gallon kits with simple math but how would I preserve the remaining ingredients? (mainly the hops/yeast)

I know these are a lot of questions but you guys really pull through for me whenever I have any kinds of questions. Just as a reminder to all of you, your help/knowledge/opinions/experiences are very helpful and I'm sincerely thankful for all of your help.

rodwha

Well-Known Member
1) A gallon is 128 oz. You lose a little bit from trub, and that little bit that's left in your bottling bucket. But you also gain a small amount with the water you use for your priming solution. So 1 gal will give you about 10, 2 gals about 21, and 2.5 gals about 26.

2) You'd need to figure out your boil off rate and how long your boil would be for to determine how much to start off with. You could play it safe and figure a small amount of top off water...

3) I'm not sure if the volume of beer makes a big difference, but I give my 4.5-5.8 gal batches about 2-3" of headspace in a bucket.

4) The saving ingredients that degrade is the reason why I will devise recipes that will use it all quickly. I recently doctored up cheap beer kits and spread my dry yeast and hops between several brews. Nothing is kept long.

bobeer

Fermentation Specalist
I used to brew all 5 or 10 gallon batches but now i can brew 2.5 gallon stovetop biab batches. i love brewing more often and having the variety. I have a 5.5 gallon pot and i usually do the 1.5 qt x lbs of grain to get my mash water amount. I also got a wooden dowel and notched it for every gallon of water in my pot. That way i was able to figure out the boil-off rate for my pot.

I get anywhere from 19-26 bottles per 2.5 gallon batch.

I have 3 gallon plastic carboys i use to ferment in but I've also used my 5 gallon carboys too. It doesn't really matter. just fix a blowoff tube if you're worried about headspace.

I usually store any unused yeast in the fridge and unused hops go sealed up in the freezer. unused grain is best used asap so it doesn't go bad and cause poor efficientcy. its also best to use your washed or wet yeast asap. dry yeast lasts longer in your fridge I've found.

cheers!

Stas StoLat

Member
So, I'm a new brewer. A couple batches under my belt. I want to start getting into experimental brews or just test brews to see if I'd like something in a bigger batch. I also want to go a lil smaller to be able to drink more varieties of beers to get their flavor profiles. My questions are:

1) Approximately how much beer will 1 gallon brews, 2 gallon brews, and 2.5 gallon brews produce? (12oz./22oz. bottles)
2) If I wanted to do 1 gallon, 2 gallon, or 2.5 gallon brews, how much water would I have to start the boil with?
3) How much head space would I need in a carboy? (I guess what I really want to know here is what kind of primary/secondary fermenters I would need to be buy for each)
4) I know I can scale down all 5 gallon kits with simple math but how would I preserve the remaining ingredients? (mainly the hops/yeast)

I know these are a lot of questions but you guys really pull through for me whenever I have any kinds of questions. Just as a reminder to all of you, your help/knowledge/opinions/experiences are very helpful and I'm sincerely thankful for all of your help.
1) Do the math
2) If I were doing a x-gallon batch, I would use x-gallons of boil, unless I was saving space for a sparge, the I would save x-gallons for a sparge and deduct form that from my total boil so that it evened out at the end.
3) Don't be afraid of too much head space. If you are concerned, lay some CO2 on top
4) refrigerate all unused ingredients.

NobleSavage

Member
After starting with 5 gallon batches, I have been brewing 2.5 gallon batches for the last handful of years - I have found this is the sweet spot for me between having a variety on hand and 'reward for effort'. I tried 1 gallon batches for a little while but that was just not enough.

2) The amount of water you start with depends upon your brewing method (extract vs all grain), how much you will leave behind in the kettle when you transfer to the fermenter, and finally on how much you leave behind in the kettle fermenter after you bottle or keg.
• When you transfer from your fermentor to your keg or bottles you will leave behind the trub (sediment at the bottom of the fermenter) this will cause some loss. The actual amount will depend upon your batch size, fermenter, and amount of dry hops added. Best way to figure this out is simply through brewing and observing how much you lose when you package your beer.
• After your boil, if you dump everything into your fermenter your trub loss or kettle loss will be zero. Some brewers try to leave as much of the trub behind in the kettle, if you do this you will have to factor the amount left behind into your water lost during the process.
• If you are brewing extract batches, your main loss of water will be boil off. To calculate your boil off rate boil a gallon of water in your kettle - the difference between what you started with and what you ended with is your boil off rate.
• If you are brewing an all grain batch you also have factor in water that is absorbed by the grain during the mash.
I recently started using an electric all in one system (Anvil Foundry) so I have been trying to zero in my process losses. For my last batch I used the following:
I started with 4.00 gallons of water and lost about 0.35 gallons due to grain absorption, this left 3.65 gallons in the kettle for my boil. During the hour boil I lost about 0.50 gallons leaving me with 3.15 gallons. After chilling the wort its volume was closer to 3 gallons, I then transferred 2.75 gallons to my fermenter and had approximately 0.25 gallons left behind in my kettle.

So, 4.00g - .35g(grain absorption) - .5g(boil off) - .15g (shrinkage) - .25 (trub loss) = 2.75 gallons in my fermenter.
Then when I keg this beer, I know from past experience that I will leave roughly 0.25 gallons of trub/beer in my fermenter, so 2.75 - 0.25 (trub loss in fermenter) = 2.5 gallon in my keg.

Using software like Beersmith or Brewfather will make these calculations much easier (both have free trial periods for you to play with).

3) For my 2.5 gallon batches I primarily use 3 gallon plastic carboys but do have a few 5 gallon ones. Too much headspace can impact flavor in some beers. If I do have to use my larger carboys I make sure not ferment any NEIPAs or other heavily hopped beers due to oxygenation concerns (larger head space will definitely lead to more oxygen in the fermenter. For the same reason, I do not like to use the larger carboys for lagers or other longer fermenting beers. Having said that, don't worry too much about it - maybe stick to a fermenter 20% larger than what you are fermenting or the 2-3" rodwha mentioned above.

4) Best way to store an opened bag of hops is with as little oxygen as possible and in the freezer. I use a vacuum sealer and like to put the original foil bag in the plastic vacuum bag when I seal it (I think I picked that up from a post on here). If you do not have a vacuum sealer, try to squeeze as much air out of the foil bag as possible, roll it up and tape it shut and still store in the freezer. As for yeast, you will be fine pitching a full pouch into a 2.5 gallon batch. If you do want to save yeast (and thereby save some \$) you can make a starter and pitch some and save some. I usually make a 2L starter, when it is done I put in the fridge, decant the beer and split the yeast into 4 mason jars - each one is generally good for one 2.5 gallon batch.

Sorry for the long winded answer!

Stormcrow

Well-Known Member
You can get one gallon glass carboys. (If you fill up to the letters on the side, you should have enough headspace. ) If you split a single two or three gallon batch into these, it allows you to experiment with different dry hoppings, yeast, etc. in each one, in essence making a couple or three different beers from a single brew day. Good way to learn a lot about hops.