No lag phase

Hey guys,

First post. I'll make it short and sweet...

I did my first all grain batch today. Made a healthy yeast starter and just slightly under pitched. Very slightly...

Anyway, I checked it about 2 hours after pitching and it is already actively fermenting. I've never seen anything like it and don't know what to think...

Thoughts are appreciated. Should I be thinking really healthy yeast and good fermentation or is there a problem here? Thanks for any input...


Brad


Sent from my iPhone using Home Brew

 

fermentation starts almost immediately and you're worried there's a problem?

RDWHAHB! most people would be delighted. just make sure you're keeping the temp down

 

Some (mostly the more geeky types) refer to the initial period of fermentation (when the yeast is adapting to its new surrounding) as the lag phase. This happens very rapidly, commonly within hours. (see Dr. Fix "Principles of Brewing Science" "Fermentation Stages") This stage should not be confused with a slow start of fermentation. With the exception of the first few hours, where oxygen is rapidly absorbed, yeast preform very predictably and as a direct function of the available sugar.

So, what most homebrewers refer to as a long "lag phase" is an indication of a low initial cell count or a low gravity beer.

However, fermentation can be too fast. If the rapid growth is caused by an elevated fermentation temperature (which is unfortunately all too common) then you can expect the flavor to be impacted. If it is caused by too high of a cell count (which is rare but possible) you can expect very little yeast character to be imparted to the beer.

To see this you can play with this fermentation model:
http://www.woodlandbrew.com/2014/05/fermentation-model.html

 

I agree the only concern would be if the fermenter was too warm. It can get up to 5-7 degrees above ambient temps during an active ferment.


Roed Haus Brewery

 

If you pitched a full starter at (or near) high krausen, I typically have very short lag periods since I'm pitching VERY active yeast. I've also had this happen with top-cropping, for much the same reason.

If your temperature is too high, that's a cause for concern. But beyond that it's probably nothing to worry about.