Smaller batch size question

[Rladd]

Hey everyone,

I am new to homebrewing and was looking to make a 5 gal recipe to 3 gal. I know how to scale the ingredients down to get to what I'll need. I however don't know if I scale down the boil times or water used during the brewing. Could anyone help and share some insight?

Below are the instructions:

Mash all grains in 1 gal water at 158oF for 30 min. Sparge at 170oF to make 2 gal. Add malt & 1 1/2 oz. Centennial. Boil for 60 min. adding 1 oz. each Centennial & Mt. Hood at 30 minute mark (mid-point of boil) Add 1oz of Cascade at 55 minute mark & Strain into fermenter filled with 2 1/2 gal. ice cold water. Pitch yeast when cooled to 80oF or lower. After blow-off is complete (approximately 4 days) sanitize and add 1oz each Cascade and Citra to fermenter (dry hop).

Would I use the same calculations as the ingredients for the water used? Eg: 1 gal is used at boil, do I do .6 gal (10 cups)?

Thank you for your help!

 

[TaylorT]

You should scale all of the volume/mass amounts, but not the times.

If the recipe calls for a 60 min boil, then do a 60 min boil with the same timelines but with less hops, etc.

That sounds like a partial mash, so I'm not sure about how that would scale down, but I scale down 5 gallon full all grain recipes to 2.5 gallons by just halving everything.

 

[flyfishnevada]

Remember, the boil off rate remains the same. If you lose one gallon per hour in that pot when boiling 5 gallons, for instance, you'll lose one gallons per hour when boiling 2.5 gallons in the same pot. It's not a percentage, it's a gallon/hour rate. Adjust accordingly.

 

[radwizard]

Are the grains already all mixed up? If you have all the ingredients to do a 5 gallon batch, why don't you just split it? It seems like it would be easier.

 

[Rladd]

I will definitely keep that in mind. I'll be brewing this Saturday and it'll be my second batch. First one came out pretty good. But, it was from one of those one gallon kits...need I say more.

I later went to my LHBS and purchased some larger and better materials. I have two three gallon PET carboys (since I have limited space in my apartment) and that's why I was wanting information about splitting down a recipe. The ingredients I bought already are portioned out for my 3 gallon recipe (nothing extra).

Thank you all for your input. I look forward to brewing and learning a lot more!

 

[bobeer]

I don't want to the throw you off since you have instructions for your batch already but here's I how scale down everything but the grains/hops/yeast...

I brew 3 gallon batches during the winter months but I have most of my recipes written in 5 gallon batch size. I scale the ingredients down in beersmith and I use the 1.30 quarts X total lbs of grain to get my mash volume. That stays the same no matter what size I'm brewing per style. Then I know my 5.5 gallon pot boils off 1 gallon an hour and I know for most 3 gallon batches I will lose about 1 gallon of water due to grain absorption during the mash. So I sprage with about 2+/- gallons to get me up to my boil volume. Again this is with most 3 gallon batches. If I'm brewing a big beer, or doing longer than a 60 minute boil, then things change slightly.

So I guess you could say I keep everything pretty much the same as if I was brewing a 5 gallon batch. Some things change but the way I get to those things doesn't really change much. Heh, if that makes any sense!

 

[Rladd]

You should scale all of the volume/mass amounts, but not the times

How do I scale them?

 

[Rladd]

Actually, that did help a lot. Thank you! I think I get it now! Thank you everyone for the help.

 

[CGish]

bobeer has you on the right track.

You could also look at Brewer's Friend. It will allow you to scale a recipe.

You say you have two three gallon carboys - The largest batch I would ferment in a three gallon carboy is about 2 gallons. You need some headspace. If you want to do three gallon batches, go to Walmart or a home improvement store and buy a white five gallon paint bucket. It will work perfect for five gallon batches.

 

[TaylorT]

How do I scale them?

As CGish mentioned, brewing software will scale recipes for you. There's a sub-forum here that has many options, just pick one that works well for you.

You could always just scale the ingredients with a calculator. I did some of my earlier 5->1 gal brews that way without issue, but the software will help with strike water temperature and other things.

 

[bobeer]

How do I scale them?

homebrew calculators are the way to go because IBU's aren't halved when only brewing a half batch of something. You can get away doing that with the grains for the most part but hops aren't the same. If you do half the hops you'll still get a drinkable beer but it wont necessarily be the same beer as if you brewed a full batch of it per the recipe. whether you care or not is up to you

I strongly suggest investing in beersmith if you're going to do a lot of scaling. Like I said above I brew 3 gallon batches on my stove when I don't feel like braving the cold outside. Beersmith is very accurate and easy to scale recipes up or down with.