Beer experiment philosophy – is your Control my Control?
Posted: Fri May 05, 2017 5:49 pm
For those who do not know me, I have a doctorate degree in physiology, and I am currently working in clinical pharmaceutical research. (This is not bragging, just to tell the reader I have been running / reading / reviewing experiments for a while).
I have been reading many beer/brewing papers and beer experiments in the recent past. Most (homebrew) beer experiments that we have seen in the recent past compare the standard process of that brewer (aka control) for brewing a given style with the same process plus the addition of an experimental variable. In fairness, in research papers many times they compare more than one experimental treatment to a control. Similarly to the mentioned homebrew experiments, when one want to test something at home, one will do the same, brew one beer with the standard process and another beer with the standard process plus the experimental variable and compare them.
Assuming taste is used as the metric to compare the beers, sometimes the comparison will yield a significant difference that the brewer (friends/ colleagues) can taste blindly, sometimes this difference is detected by such a majority that would yield a statistically significant difference, sometimes no significant difference can be detected. When discussing why differences were detected or not, it is important to critically think what can affect the odds of detecting a significant difference. These are some key factors:
1. Brew a beer that you can brew with little or no flaws every time. Flaws can confound the tasters; if flaws are more noticeable than your treatment, the treatment effect will be difficult to detect for most tasters. Also, if two beers that you brew to be identical are different, how can you expect to detect whether the difference is due to the treatment, or to your brewing variability. This is not the time to brew something you have not brewed before.
2. Brew a beer style that maximizes the odds of detecting a difference, use styles with subtle flavors, and especially think about the postulated effect if it the effect is taste-related. For example, do not use IPAs for taste effects, for an astringency effect, weissbier is a good style, for a malty effect, Munich helles may be better than a subtle beer with little malt flavor (light American lager)
3. Use ingredients you have used before for the same style. Use a newly opened bag of fresh hops.
Can your process affect the results?
I think it does. Your process is your brewhouse signature. Two brewers can do everything perfect as stated above, one finds differences between the control and the experimental treatment and others does not. What happened? Many times, brewers get to a great beer through different processes. Some use little carbonates in stouts, some use high-bicarbonate water; some get maltiness through decoction, some get maltiness using specialty malts in an infusion mass; some add dark grains at the beginning, some at the end of the mash; some boil for 120 min, some only for 60 min; some do thorough cold break separations; others not so much; some overpitch with no problem, some underpitch with no problem. An experimental treatment that can make a significant difference in some great brewer’s process, may not make a difference in other great brewer’s process.
Would you add other factors to this list? Would you amend this list. Your comments, thoughts, and corrections will be genuinely appreciated.
Cheers,
I have been reading many beer/brewing papers and beer experiments in the recent past. Most (homebrew) beer experiments that we have seen in the recent past compare the standard process of that brewer (aka control) for brewing a given style with the same process plus the addition of an experimental variable. In fairness, in research papers many times they compare more than one experimental treatment to a control. Similarly to the mentioned homebrew experiments, when one want to test something at home, one will do the same, brew one beer with the standard process and another beer with the standard process plus the experimental variable and compare them.
Assuming taste is used as the metric to compare the beers, sometimes the comparison will yield a significant difference that the brewer (friends/ colleagues) can taste blindly, sometimes this difference is detected by such a majority that would yield a statistically significant difference, sometimes no significant difference can be detected. When discussing why differences were detected or not, it is important to critically think what can affect the odds of detecting a significant difference. These are some key factors:
1. Brew a beer that you can brew with little or no flaws every time. Flaws can confound the tasters; if flaws are more noticeable than your treatment, the treatment effect will be difficult to detect for most tasters. Also, if two beers that you brew to be identical are different, how can you expect to detect whether the difference is due to the treatment, or to your brewing variability. This is not the time to brew something you have not brewed before.
2. Brew a beer style that maximizes the odds of detecting a difference, use styles with subtle flavors, and especially think about the postulated effect if it the effect is taste-related. For example, do not use IPAs for taste effects, for an astringency effect, weissbier is a good style, for a malty effect, Munich helles may be better than a subtle beer with little malt flavor (light American lager)
3. Use ingredients you have used before for the same style. Use a newly opened bag of fresh hops.
Can your process affect the results?
I think it does. Your process is your brewhouse signature. Two brewers can do everything perfect as stated above, one finds differences between the control and the experimental treatment and others does not. What happened? Many times, brewers get to a great beer through different processes. Some use little carbonates in stouts, some use high-bicarbonate water; some get maltiness through decoction, some get maltiness using specialty malts in an infusion mass; some add dark grains at the beginning, some at the end of the mash; some boil for 120 min, some only for 60 min; some do thorough cold break separations; others not so much; some overpitch with no problem, some underpitch with no problem. An experimental treatment that can make a significant difference in some great brewer’s process, may not make a difference in other great brewer’s process.
Would you add other factors to this list? Would you amend this list. Your comments, thoughts, and corrections will be genuinely appreciated.
Cheers,