Best way to scale DOWN a recipe

[Mike Newman]

Hello everyone! I am a small batch brewer that is looking for a way to scale down 5 gallon recipes to fit my 2-3 gallon set up. I currently am doing BIAB batches where I ferment in a temp controlled mini fridge (too small for 5 gallon carboy)

My question is simple...
Can I just cut the recipes in half or is it more complicated than that?

 

[Oginme]

Brewing software would help with scaling a recipe to whatever size you need. Having said that, just taking a recipe and scaling based on the ratio of the batch size would be easier and give you something pretty close to what software will produce.

 

[SoCal-Doug]

Using a straight divisor will sorta-kinda work and in many cases work out ok. But... Anytime you use someone elses recipe, whether its the same batch size or not, you'll need to consider a few things. Your efficiency is probably not the same as theirs. Your boil-off rate may be different, deadspaces, volumes, methods (full AG with sparge vs BIAB vs whatever), and other topics.

To keep it simple, I would say to use the same grain ratios (percentage of each malt type), then adjust them collectively for the desired OG. Then adjust for efficiency and processes from there if you can. Hops also. Look at the original IBU's and times, then adjust what you will use for the same IBU's. Software like beersmith has tools for adjusting things like this.

I always try to share recipe's in percentages, IBU's and gravities instead of pounds/ounces/gallons. Then let the next brewer adjust accordingly for their own system and quantity.

 

[Big Monk]

Hello everyone! I am a small batch brewer that is looking for a way to scale down 5 gallon recipes to fit my 2-3 gallon set up. I currently am doing BIAB batches where I ferment in a temp controlled mini fridge (too small for 5 gallon carboy)

My question is simple...
Can I just cut the recipes in half or is it more complicated than that?

Convert the recipe to percentages and it will scale to any grain bill size. You need to specify two variables anyway in a recipe: batch volume and total grain weight.

 

[Leezer]

I also brew 2 to 2.5G biab batches and use Brewers Friend to scale down 5G recipes. I find it pretty easy to use. As mentioned above, you do need to make some adjustments to achieve desired OG and also IBUs based on the hops you will be using. I’ve been trying to track my efficiency so that I can factor that in more accurately as well.

 

[Lefou]

Speaking of efficiency, yesterday's brew netted me a mash/lauter gain of almost 10%. Usually I will add extra grain, but this helped a lot. What's not to like about that?

I changed a couple of things around from the last time. Better grain, obviously, and a longer mash.
I usually calculate a 70% efficiency to get my equivalent grain weights, but knowing I had good grain and compensating a bit made a big difference. Typically a 2.5 or 3 gallon mash can be halved from the 5 gallon batch, but you have to do a few brews and know your system. A good calculator always helps.

 

[smyrnaquince]

See my reply to a similar question:
Reducing Recipe Quantity