When I brew for myself, I brew 5 gallon batches. When I brew for “The Dash”, which is code all the Brew Dudes out there in Internet Land, I brew 1 gallon batches because those beers are for learning purposes, mostly. I mean, I still have beer in the end, which is always a good thing.

For a while, I wanted to know if my 1 gallon brewing process was as good as my 5 gallon brewing process. To get a definitive answer, I planned to brew a recipe for both volumes and then compare the outcomes to each other. Here’s a video where we try to figure out if batch size impacts flavor:

The Experiment Plan

My 1 gallon batches tend to be SMaSH (Single Malt and Single Hops) beers which I didn’t think would be great to apply to this experiment. To scale a SMaSH beer recipe from one gallon to five wouldn’t be challenging enough for this experiment. I wanted to brew something with a little complexity but not so complex that it broke the bank, a recipe that may have a few aspects get lost in translation from one size to another. So, I came up with an American Pale Ale recipe that I could formulate for a batch of 5 gallons and 1 gallon.

The Recipe

These Brew Dudes have toyed with sharing all of our recipes through just grain bill percentages and alpha acid targets but most times it’s just easier to share the exact measurements for the recipe we brewed. For this experiment, I needed to figure out these targets so I could scale it for both batches. Here are the targets:

  • American Pale Malt – 95% of grain bill (95.2381% to be exact)
  • American Caramel Malt 40°L – 5% of grain bill (4.7619% to be exact)
  • IBUs – 42 (using Cascade hops only with 60, 15, and flameout additions)

The other items I kept in mind were water, which was my tap water adjusted with gypsum so that I had a 1 to 1 ratio of Chloride to Sulfate and decided my ABV for both beers should be around 5% so I calculated my grain bill for that alcohol strength.

I used the free version of BeerTools to figure out all the quantities of malts and hops to hit my targets. After a few adjustments, I had 2 separate recipes for each batch.

The Results

I took measurements for each stage of the brewing process, including pre-boil gravities. With all the calculations, I learned that my mash efficiency was much better than the 72% default setting. For both beers, it was more like 83% based on the refractometer readings.

At the end of each brew session, I pitch the same yeast: a packet of US-05 yeast went into the 5 gallon batch and a third of a packet went into the 1 gallon batch. Both beers fermented well, they were sitting right beside each other in my basement. The 1 gallon batch appeared to take longer than the 5 gallon batch.

After fermentation was over, both beers were carbonated in kegs for tasting. When I tasted both beers for the first time, I didn’t notice much of a difference. The 5 gallon batch had a slightly different aftertaste, which seemed to me to be hop derived.

When I brought them over to Mike for a triangle taste test. He couldn’t tell the difference between the two of them, which was the ideal outcome. I was hoping that my brew process was good enough to produce similar beers for for either batch size. For this experiment, it seemed to be the case.