As a professional scientist, I absolutely love any opportunity to meld the art and science of homebrewing. The intersection of chemistry and biology with the senses of taste, smell, touch, and sight creates endless hours of enjoyment. Even more so, I love playing with ingredients and processes to explore this beer landscape.

I’m not alone in this passion for the scientific side of homebrewing, either–two particularly prominent efforts (among others) have a solid hold in our brewing culture. The first of these is Experimental Brewing, by Denny Conn and Drew Beechum. In addition to a great website, they host one of my favorite brewing podcasts. Their mode of experimentation is to recruit IGORs (Independent Groups Of Researchers) who brew parallel batches of beer to test brewing hypotheses. The other major player in the world of homebrew experimentation is Brülosophy. This brewing team regularly investigates single variables (e.g., yeast pitch rate or addition of gelatin finings) of relevance to homebrewers, examining what (if anything) matters for your typical 5-10 gallon batch.

Over the past year or so of following these efforts, I have found some great value and food for thought in all of their experiments. The associated podcasts and blog posts pose interesting questions, and often challenge the received wisdom of homebrew tradition. Yet, the scientific side of me often wonders: Is it really science?

The short answer to this is, in my opinion, both yes and no.

Homebrew experiments are often scientific in that they propose hypotheses, design procedures to test the hypotheses, and collect data for later analysis. This is certainly necessary for science, but it’s not entirely sufficient.

I should preface my explanation on this latter point by saying that my opinions here are not intended as unthinking criticism of some really great homebrew experimentation. I love and appreciate what others are doing. That said, I do notice that the work is sometimes misused or misinterpreted within the broader homebrew culture. Some basic scientific safeguards could help to maximize the value of homebrew experiments and minimize confusion. So, my post is less about breaking down the current “system” (if it even really is a system) and more about what we can add to improve the value of homebrew experiments. Even more so, it’s about how those of us who read the “exbeeriments” should interpret them!

• Expand the brewing scenarios. As is readily acknowledged by most brewing experiment writers, results of a particular experiment are really only applicable to those experimental conditions. For instance, if you find that there is no difference between a 20 minute and a 60 minute boil for a stout, the results probably shouldn’t be extended to a blonde ale. More experiments at a homebrew scale are needed!
• Emphasize limitations. This follows pretty logically from the point immediately above. I think that most of the brewing experiment write-ups out there do this pretty well, so it’s more of a caution for those who read and try to apply the results.
• Record methodology in detail. Brülosophy sets a high bar for this, and is able to do so because their brewing is done typically by a single person. The IGORs do good work, but the distributed nature of the brewing means that a lot of the details on their brewing setups and techniques aren’t immediately available. Different brewers often have very different techniques. Unfortunately, this can raise a lot of basic questions about experimental results and interpretation. Experimental Brewing did a great episode highlighting differences between brewers’ techniques and how it affected an experiment related to bitterness. This was indeed illuminating!
• Pair sensory perception analysis with laboratory analysis. The aforementioned Experimental Brewing episode did this really well, in terms of evaluating differences in IBU yields across different recipes and setups, as did a Brülosophy exbeeriment related to loose vs. bagged hops in the kettle. This approach really helps to nail down the interpretation of results (especially for those related to bitterness), although I also admit it is potentially expensive.
• Engagement with the brewing literature. There is an ocean of literature from the commercial brewing world, much of it published in formal scientific journals, yet this is rarely if ever incorporated into the homebrew world in any meaningful way. There are reasons for this, of course…for instance, much of this literature pertains to giant commercial brewing setups and cannot be transferred confidently to the homebrew scale. Also, much of the literature is technical and paywalled, so might as well not exist for most hobbyists.
• Peer review and formal publication. Is it time for a Journal of Homebrewing Science? If there is a single thing that would improve homebrew experiments, it would be formal, independent peer review and a mechanism for publication of these reviewed results. Comments on blog posts do provide one form of review, but this is not always reflected by modifications in the experiments or changes in interpretation of the experiments. If I were to be really ornery, and I suppose I am because I am writing this post, I would suggest a multi-step peer review process handled by an independent review or editorial board for brewing experiments.
  • Design the experiment, and open it up for input.
  • Modify the experimental design as required.
  • Run the experiment.
  • Write up the results, and open the write-up for review.
  • Following the review, revise the write-up accordingly.

Overall, I love the experimental approach to homebrewing. I think it illuminates some really interesting facets of our hobby, and helps brewers to be more and more thoughtful in their technique. We’re now at the stage where we can push things to the next level–so let’s do it!