The joy of krausen.

Krausen? Yes, Krausen. Not the Kraken.

Krausen is a foam which forms on top of the wort once fermentation has commenced. It's usually white or creamy but sometimes is darker depending on the yeast or the wort colour (e.g. a stout can be quite a bit darker, etc). Being that tell-tale sign that fermentation has started, it's a grand assurance that everything is on the right track.

Usually, the signs of fermentation are visible between twelve and forty-eight hours after pitching the yeast. This all depends on the yeast and how you pitch it.

The main signs that fermentation have commenced are:
* krausen
* condensation inside the lid of the fermenter
* bubbling air lock.

Krausen? As above.

Condensation? Yes, because the process is exothermic. If the ambient temperature is say 17C, then there's a good chance that the fermenter will be about 20C.

Bubbling air lock? Yes, CO2 being released by the fermentation has to go somewhere, but atmosphere needs to be excluded. Oxygen at this stage is a bad thing for beer making, as is particulate (dust, etc) or biological (wild yeast, bacteria, insect, etc) contamination.. If it's not bubbling, don't worry - that's usually a sign that there is a leak. However, your fermentation chamber will remain pressure-positive until after you have achieved FG so there is a limited chance of oxidation or contamination. CO2 will still be coming out of solution, for the most part, after FG is achieved.

As long as you have at least one of the three conditions above, there's a very high chance that fermentation is underway.

If after three days from pitching there is limited or no sign of fermentation having commenced, draw off a sample and measure the SG. If there is no change from OG, it would be advisable to pitch a new batch of yeast. If there has been a decrease in SG, then fermentation is taking place albeit slowly.

In general, if your OG is <1080 then a standard pitching, single fermentation in the vessel is adequate. If you're working with higher SG wort, then some special rules come into play but I can tell you more about that another time.

Also, take into consideration the temperature of where your fermenter is sitting. The ideal temperature range for the yeast you're using should be on the packaging or at least available at the supplier's web site. If the temperature is too low, fermentation may either not commence or commence very slowly. If the temperature is too high then fermentation may kick off, perhaps violently, and be very short-lived. A hot fermentation has some negative side-effects, the least of which can be a brutal hangover.


So - why all the talk about the Joy of Krausen?

I feel joyous.

My new batch has krausen.


Cheers!!