Rapid fermentation

[Mike]

I put down a stout homebrew on Friday (19th Oct) and within a few hours it was bubbling nicely. On Saturday and Sunday it was gassing like a steam train - constant flow through the air lock. Today (Monday) it has pretty much stopped - 1 blip thorough the airlock every 5 minutes. Temp has ben steady between 22 and 24. Gravity at start was 1048. I am realtively new to this (4th brew only) but the past 3 brews have happily bubbled until 5-7 days.

Has it done its dash?

Can the fermentation process use up the yeast and not be finished?

 

Comments/ help please.

 

 

 

[Smiffy]

You need to monitor the gravity to know what has happened, and whether it has finished fermenting. It may well have done due to the elevated temperature. It will be a good idea to leave it for a few more days, ideally at a lower temperature, for the yeast to eat up the strange flavours that high temperature fermentation creates.

Yeast doesn't get "used up", sugars do.

[Mike]

Thanks for the quick reply - still lots to learn. I have moved the brew somewhere a bit cooler and will take a gravity reading later.

[Nathan Murrell]

A quick google search will provide you with the answers to this question...but in a nutshell...

1) don't use your airlock and the frequency of its bubbles as an indicator to tell you when fermentation has finished. You can't get a 100% seal anyway. You'll find a lot of people just use gladwrap on the top of their fermentors instead.

2) take fg samples from your tap. When the samples are the same two days in a row you're done. However there is nothing wrong with leaving it going for 10 days...or even two weeks as some people do. I had to leave my last brew for six weeks due to family circumstances and it came out as one of my best so far.

Also, not sure what yeast you used and I have never brewed a stout, but that ferment temp may be a bit on the high side too.

There's plenty of stuff to be learnt but that's part of the fun! No doubt it will still taste pretty good ;)

Haha...took too long to type and was beaten to it

[Mike]

Good to know - thanks for the post. Have moved the brew to a slightly cooler location and will take a gravity reading later today and again tomorrow to see what is going on. Nice to hear that it can stay in the fermenter for a few more days without doing any harm. Hope it tastes as good as it smells.