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As it can be seen in this Q/A many beginner brewers observe a bloomed fermentation, excessive for one day, then no sign of fermentation but by measuring the gravity.

I recently got this problem for a german style wheatbeer. The beer itself ended-up quite nice.

What would be the known downside in term of beer quality from such a fermentation, if any?

Benoit
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    What was your pitch size and fermentation temperature? Speed itself will not matter all that much, but reasons for slow or fast fermentation will. – Mołot Jan 04 '19 at 13:09
  • For 24 litres with a yeast optimal for 20 to 24 Celsius. I put the yeast at 24° and it reached 25°/26° pretty quickly while outside temperature was around 20°. Then it dropped to 18° 3 days later. – Benoit Jan 05 '19 at 01:24

1 Answers1

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Usually a fermentation happens quicker than normal for 3 reasons. Poor oxygen, large yeast pitch, warm temperatures.

Low Disolved Oxygen: Yeast needs oxygen in wort to multiply. When oxygen is gone it's one of the triggers for yeast to move from growth phase to feeding phase. This can result in off flavors and mostly poor attenuation, incomplete fermentation

Large Pitch: Beer styles that have clean ester profiles do very well with large pitch rates, even full pitch by using the entire cake or trub from a like batch. Most esters are made during yeast growth, with larger pitches the growth phase is short or skipped all together greatly reducing growth esters. This can be bad for styles that are ester dependant like belgians, saisons etc

Warm Temperatures The warmer the temperature the higher the metabolism of the yeast. Everything happens quicker. In this haste a lot of undesirable chemicals are produced. Bad esters and larger molecule alcohols. Leaving a beer hot from fusal alcohols and even have extremes of nail polish aromas.

Hope this helps.

Evil Zymurgist
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