Will scaling a recipe from 5 gallons to 1 gallon introduce significant differences?

Question

Will scaling a recipe down to 1 gallon (i.e.: dividing the amount of each ingredient by 5) produce a pretty close approximation of the results of a full 5 gallon batch? Are there any additional considerations in brewing such a small batch?

I'd like to do some small experimental batches over the winter, using a 2-gallon stockpot on the stovetop instead of my usual brew kettle on an outdoor burner setup. I want to make sure they're pretty close to what a 5-gallon would end up like (esp. taste) so I can decide whether to go ahead with full batches of these recipes in the spring.

Answer 1

Basically, yes. Small batch brewing is great for what you're talking about experimenting with different ingredients, recipes, etc.

They guys at Basic Brewing Radio do it all the time, and here's a pretty good article from BYO, but in general the proportions of the ingredients should be the same. So, if the small batch is 3 pounds 2-row, and 2 pounds wheat, the 5-gallon batch should have 60% 2-row and 40% wheat.

Answer 2

Most things will scale just fine linearly, the exception being hop utilization. Wort gravity has an effect on utilization; the higher the gravity the lower the utilization. This is why extract brewers who don't do a full wort boil get less utilization that a full wort boil; the gravity of the wort during boil is higher (they then add water after boil to dilute to target gravity).

I'm not sure if going from 5 to 1 gallon will have a significant effect, but you can play with this calculator to see what happens. Many brewing software programs can do this for you. Unfortunately all of these are only methods to estimate the final IBUs. The only way to determine actual IBUs is to have a lab measure it.

Answer 3

I currently brew at a 1.5 gal system. The big things I noticed moving from a 10 gallon rig were the changes in brew house efficiency and hop utilization. The dead loss at the bottom of your mash tun and kettle will be more pronounced. Longer sparging and whirlpooling are suggested.