Does lager fermentation temperature really matter? Twelve taste tests, three significant results
I have always repeated the rule that lagers must ferment cold, so a roundup of Brülosophy's past lager fermentation temperature experiments caught my attention. The author, Marshall Schott, gathers twelve of their exBEERiments, each run as a triangle test: tasters get three samples, two identical and one different, and try to pick the odd one out. A result only counts as significant below p = 0.05, and he is careful to say that a non-significant result does not prove temperature has no effect, only that this panel could not reliably tell the beers apart.
Out of the twelve, only three came out significant. One used SafLager W-34/70 at a very warm 82°F (27°C) against 60°F (16°C), and the one tester who noticed a difference mentioned sulfur. Another used WLP940 Mexican Lager, where eleven tasters preferred the cool version and nobody picked the warm one. The third used Imperial L17 Harvest, where the correct tasters could not even agree on what was different. Several brewers also ran their own semi-blind tests and felt sure of the difference, yet the blind panels did not back them up. Even the 19 BJCP judges in the first test found the odd sample only seven times.
What I found interesting is the pattern in the yeast. The strains behind Pilsner Urquell-style beers were non-significant every time, while all three significant results involved Frohberg-type strains. The author's takeaway is that yeast may be more robust than many of us believe, and that a 20°F (10°C) gap is smaller in practice than it sounds.
Personally I read this as permission to relax a little, not to throw out the thermometer. If you cannot hold a lager chamber at 50°F, these results suggest a cleanly fermented beer at a warmer temperature is still very drinkable, and it is a good reminder to test things on your own beer instead of trusting tradition blindly.
Source: Brülosophy
Out of the twelve, only three came out significant. One used SafLager W-34/70 at a very warm 82°F (27°C) against 60°F (16°C), and the one tester who noticed a difference mentioned sulfur. Another used WLP940 Mexican Lager, where eleven tasters preferred the cool version and nobody picked the warm one. The third used Imperial L17 Harvest, where the correct tasters could not even agree on what was different. Several brewers also ran their own semi-blind tests and felt sure of the difference, yet the blind panels did not back them up. Even the 19 BJCP judges in the first test found the odd sample only seven times.
What I found interesting is the pattern in the yeast. The strains behind Pilsner Urquell-style beers were non-significant every time, while all three significant results involved Frohberg-type strains. The author's takeaway is that yeast may be more robust than many of us believe, and that a 20°F (10°C) gap is smaller in practice than it sounds.
Personally I read this as permission to relax a little, not to throw out the thermometer. If you cannot hold a lager chamber at 50°F, these results suggest a cleanly fermented beer at a warmer temperature is still very drinkable, and it is a good reminder to test things on your own beer instead of trusting tradition blindly.
Source: Brülosophy
Comments 0
Leave the first comment, in any language.
Log in to comment