Expert: John Snyder - 4/26/2009

Question
QUESTION: This is my second brew...  this time I've chosen a beer kit named "brewferm", type: "Ambiorix".  I followed the instructions and last night (I added the yeast yesterday evening) some foam and a bit of bubbles appeared.  This morning the fermentation seemed to stop, there are no more bubbles and the amount of foam (visibile through the plastic fermantator) is decreasing. The temperature was 25 when the yeast was added and stayed like that throughout the time (like instructed by the manufactuer).  Why did it stop so early? could it be that I lost the brew? Can I do something?  
Thanks!

ANSWER: 25 C is a high temp,for adding the yeast.Most likely,the real active fermentation has taken place already,but there is still a slow fermentation going on.What was the S.G.at the start of fermentation?Take a S.G.reading now,then wait several days,and take another S.G.to see if the S.G.has lowered,if so,carry on with your process.

If you give me S.G.readings,I can then be more specific,as to problems,if any.

Stopped fermentations can be caused by ,bad yeast,cold temperatures,improper aeration of the wort before adding the yeast,dropping of the beer temperature lower than it was at the start of fermentation,within 24 to 36 hrs.

The fermentation could also be restarted,by a new yeast addition,and wort aeration,but that is tricky and could result in a finished beer that had a lousy flavor and aroma

---------- FOLLOW-UP ----------

QUESTION: Hello John,
Thank you very much for your quick respond.  I did as you instructed and took an S.G on Friday.  Than, today, I took another one. The readings: Friday - 1040, Today (Sunday) - 1015.  From those readings i understand that the fermentation is still going on.  But, Still, I'm interested to know why did the "visual signs" of the fermentation disappear?  
Thanks!

Answer
That's excellent,carry on with your process,the S.G.is where it should be.CO2 bubbles trap particulate matter & concentrates it in the developing foam.EX:proteins,trub,hop resins.This matter is called Krausen,(concentrated brown foam)When the CO2 bubbles decrease,as the fermentation,slows,it causes a pressure drop in the foam,thus the foam collapses,and what remains is just a brown ring.

         John