fermentation expectations

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therebelmc

fermentation expectations

Post by therebelmc » Wed Sep 29, 2010 6:03 pm

could someone walk me through what changes to expect in the FV during fermentation please.

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Kev888
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Re: fermentation expectations

Post by Kev888 » Wed Sep 29, 2010 6:54 pm

initially very little will happen with dry yeast, as it has to hydrate and then get going (if you use a starter things are more rapid).
then it will begin to bubble, and some bubbles will begin to collect on the surface
Then it will burst into life and you'll get bubbles and froth rising, usually a few inches or more, over the top of the liquid wort
this will gradually subside, leaving dry caked on residue around the sides of the FV and small quantities of solids floating on top
it will also leave a good thick layer of sediment on the bottom of the FV
Finally the fermenting will cease (pretty much, anyway) and the wort slowly begin to clear of suspended cloudiness.
It helps to clear it if the beer is cooled.

During that time the heavy thick malty goodness in the wort is being turned into thin light alcohol by the yeasty beasties, therefore the specific gravity of the mix is reducing; when the fermentation has finished, the gravity remains consistant and can be verified with a hydrometer, which sinks further as lighter alcohol is produced from the heavier malty stuff. The change in gravity can be used to estimate the amount of alcohol produced. The final gravity can also give an indication of the amount of matter that wasn't fermented; unless something went wrong and it didn't ferment as fully as expected, a higher final gravity usually indicates more residual sweetness and body.

I hope thats what you were after, anyway. Sorry if I misunderstood and its too basic or something.

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Kev
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therebelmc

Re: fermentation expectations

Post by therebelmc » Wed Sep 29, 2010 9:15 pm

thanks Kev exactly what i was looking for. our brew has been fermenting for 4 and a half days now , initialy was very frothy say for 3 days but now there are a few bubbles on the top and a few bits floating. does that sound ok? first brew is like a new born baby , can't take your eyes off it.

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Kev888
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Re: fermentation expectations

Post by Kev888 » Thu Sep 30, 2010 10:58 am

Yes that sounds completely normal to me - good stuff! :-)

Things are slowly coming to an end by this stage - over the next few days the bubbles will more or less stop rising and the beer will gradually grow a little less cloudy, but otherwise there probably won't be a great deal of visible change after this point.

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kev
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therebelmc

Re: fermentation expectations

Post by therebelmc » Fri Oct 01, 2010 9:36 pm

SG is now around 1010, the recipe says final gravity should be 1007.although it started slightly higher than the expected 1043 at around 1050 . by tommorrow evening it will have beeen fermenting a full week. unfortunately i am away over the weekend. is it ok to leave in the FV until monday without any problems?

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Kev888
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Re: fermentation expectations

Post by Kev888 » Fri Oct 01, 2010 11:01 pm

Yep - it should be fine assuming flies etc cant get in. I often leave it 10 days to two weeks.

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Jerry Cornelius

Re: fermentation expectations

Post by Jerry Cornelius » Fri Oct 01, 2010 11:02 pm

therebelmc wrote:SG is now around 1010, the recipe says final gravity should be 1007.although it started slightly higher than the expected 1043 at around 1050 . by tommorrow evening it will have beeen fermenting a full week. unfortunately i am away over the weekend. is it ok to leave in the FV until monday without any problems?
Yes. I always leave mine 14 days before I bottle or keg them. I think it's actually better because it helps clean up yucky stuff from the yeast that you don't want in your beer. I've also gone 3 weeks without any problems.

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