### Update

• What Aeropress technique did you use in your brewing experiments?

I used the conventional methods outlined in the Aeropress instruction manual and adopted a consensus brew method from the World Aeropress Championship. I used 18 grams of coffee ground a little coarser than filter and ~250-270mL of water for brewing sans inversion.

• Were subjected allowed to supplement their coffee with additives like sugar, milk, or cream?

No. All the coffee in my experiments was prepared with no additives. Allowing guests to randomly add their own supplements would have obfuscated the results. When possible, I tried to eliminate extraneous and confounding variables in my experiments.

• Were your guests simpleton coffee dilettantes incapable of differentiating good coffee from bad? If so, their inexperience may have distorted the results and made it appears as if the blade and burr grinder were equivalent when, in fact, they were not.

I expected my guests would actually prefer the burr grinder. Most of the subjects in the grinder experiment owned burr grinders, thus they were likely pre-conditioned to favor this grinding method. Despite the presupposed bias toward burr grinders, the empirical data showed that guested did not prefer this method. It’s fun to generate various hypotheses post hoc as to why these experiments could have generated the outcomes that they did; however, in most cases, it is good practice to adopt Occam’s razor, until evidence suggests otherwise.

1. House guest are great fun because they’re indebted to you for letting them stay in your home; this means you can cajole them into doing all sorts of things they wouldn’t otherwise do.

2. A hat tip to Bud Tribble

3. I use the term experiments loosely throughout this post. I didn’t have the resources to setup a more thorough experimental design. Ideally, I would have liked to use better control conditions, larger sample sizes, more thorough subject randomization, and a more consistent testing environment.