If you’re looking for inspiration for brewing experiments, the best place to start is with a curious mind. You could be wondering about an advanced technique, or you could decide to challenge common wisdom to figure out whether it’s right. Testing basic assumptions is a great way to learn, especially when the real world seems to contradict those truths. For example, we all know that sanitation is vital in brewing and that it’s important to pitch a healthy quantity of yeast. So, why do the lambic breweries in Belgium get a pass? Questioning and investigating can lead to better understanding.
Here are three suggested experiments, along with ideas about how best to structure them. Remember, to get the most value, you want to focus on a specific question, limit your variables, accentuate the effect, and assess the results.
Experiment 1: Racking to Secondary vs. a Long Primary Fermentation
Newer brewers seem to be moving away from following a two-stage fermentation while Old School brewers swear by the process. When I started out, I read that racking to a secondary vessel improves the beer’s flavor and clarity. The rationale is that decanting the beer off the trub minimizes contact with tannins and hops sediment, and it also reduces the chance of off-flavors related to autolysis. Testing this could determine whether it makes a difference. Skipping the secondary would certainly be easier, and it would reduce the chances of oxidation or infection, but we don’t want to sacrifice quality.
We want to eliminate all differences except the racking step. That means the same wort, yeast, pitch rate, and temperature. If you’re set up for lagers, that would be a better target beer because the longer fermentation should accentuate the difference between the two approaches.
Start with a 10-gallon batch, split into two carboys. Batch one will follow the two-stage fermentation process, with the beer racked to another carboy once primary fermentation is complete. Batch two will remain in the primary carboy. When both beers are complete, the two should be packaged identically (kegs or bottles). Be sure to track the starting and finishing gravities of each one.
We can examine the differences from a couple of angles. Was the finishing gravity the same? Were head retention or clarity affected? Does one batch taste better than the other? The gravity metrics you collected will answer the first question; the other two can be tested with a blind tasting. Let a panel of judges score and rate the two beers without knowing anything other than the base style. A couple of judging runs might provide a clearer conclusion.
Experiment 2: Bittering Test—High-Alpha vs. Low-Alpha Hops
Some brewers claim that IBUs are the only thing that matter for bittering hops, so any variety will do. Others assert that filling those IBUs with low-alpha hops creates a “smoother” bitterness. Is there a discernable difference? If not, using a smaller amount of high-alpha hops would certainly be more economical.
The key variable should be bittering hops alone. Pale ale is a good base style because bitterness is a key component, and the flavor and aroma hops are less likely to overwhelm the palate. Pick two very different hops for bittering, such as Columbus and Tettnang, then set quantities to hit the same IBU target. Assuming a desired bitterness of 40.6 IBUs, for a 5-gallon (19 l) batch you’d need 0.7 oz (20 g) of Columbus (14.5% AA) or 5.1 oz (145 g) of Tettnang (2% AA) for a 60-minute boil.
Start each batch with the same base wort (e.g., split 10 gallons/38 l into two brew pots). The bittering hops will differ, but they’ll have the same flavor and aroma hops additions and the same yeast. Follow the same fermentation protocol and package as usual.
You could organize a tasting panel the same as you did the previous experiment, but a triangle test would also be a good approach. Each judge should be presented with three beers in random order, two of which will be the same. See whether your judges can correctly identify the odd beer and ask them to describe the differences. If the majority of judges can’t pick the odd one, that’s a sign that it may not matter. Then, focus on the judges who did identify the unique beer and see if their feedback correlates to the “smoother bitterness” theory.
Experiment 3: Pasteurization
Big breweries pasteurize their beer to improve shelf stability. That may be fine for bland mega-beer, but most people assume that pasteurization hurts the beer’s flavor. This might not seem relevant for homebrewers, but it’s certainly possible to test without fancy equipment. This could be a useful tool for homebrewing if the common wisdom is wrong.
Some older research indicates that American breweries applied an average of around 15 Pasteurization Units to their beer (visit https://sizes.com/units/pasteurization_unit.htm for an explanation). This can be achieved by heating bottles in a 140°F (60°C) water bath for 15 minutes. For this experiment, we can go a bit longer, say 20 minutes.
Select a fairly flavorful beer for this test and consider trying it with both your own homebrew and a non-pasteurized commercial craft beer. Put several capped, carbonated bottles in the water bath, along with a single uncapped bottle. Place a thermometer in the open bottle and start the timer once the beer hits the 140°F (60°C). After the time is up, carefully remove the bottles and let them cool to room temperature before refrigerating them.
In the interest of safety, I’d also recommend wearing eye protection and gloves and avoiding highly carbonated beer.
This is another case where a triangle test is most useful for comparing the untreated beers with the pasteurized bottles. Once again, you want to learn whether people can correctly identify the odd beer and get their preference and sense of the flavor differences. It would be interesting to see how easy it is for them to tell and whether the treated beer is perceived as worse.
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