johnnyboy1965
Landlord.
Contraversial (sp) I know, but it is the nature of the yeast beast to do its job
johnnyboy1965 said:if there is live yeast and sugar available it will carry on fermenting
johnnyboy1965 said:My thoughts are like this....people who say they have a stuck fermentation often refer to eg "OG 1.040 stuck at 1.020". Therefore there must be viable yeast in the brew, to drop it by 0.020. The yeast has done its job, its consumed all the available sugars present in the beer. Yeast will not stop working if there are sugars available, ie ..if there is live yeast and sugar available it will carry on fermenting.
My first port of call would be to take a accurate gravity reading. As home brewers tihs is impossible, but the best we can do is by using two or three different hydrometers. If you are now sure that your beer is at eg 1.020, then here is a little chefs tip.....taste it....believe me on this one......mix 1li of water and add 20g of sugar...take a sample of your beer, and taste test them side by side.markmark said:johnnyboy1965 said:My thoughts are like this....people who say they have a stuck fermentation often refer to eg "OG 1.040 stuck at 1.020". Therefore there must be viable yeast in the brew, to drop it by 0.020. The yeast has done its job, its consumed all the available sugars present in the beer. Yeast will not stop working if there are sugars available, ie ..if there is live yeast and sugar available it will carry on fermenting.
Even if it gets cold?
I personally think that most stuck fermentations are caused by the temperature being too low. At the start of ferment the conditions are ideal for the yeast to work....aerated wort, food, no alcohol present, fresh and healthy yeast.....a small temperature drop won't matter too much, and the initial stages are very exothermic too. But as the conditions deteriorate (in terms of whats best for the yeast), the yeast is more likely to drop out if it gets a little cold.
What advice do we normally give for a stuck ferment.......rouse gently and increase the temperature a little??
johnnyboy1965 said:Every single yeast strain will carry on working if there is sugar present, you cannot stop it.....unless you add (I think its potassium sorbate) which kills off any live yeast.
If you brewed a beer with a bog standard yeast at 1oC, eventually it will ferment out.
76 x 25li AG brews might prove you wrong...stuck ferments....Zerocalumscott said:johnnyboy1965 said:Every single yeast strain will carry on working if there is sugar present, you cannot stop it.....unless you add (I think its potassium sorbate) which kills off any live yeast.
If you brewed a beer with a bog standard yeast at 1oC, eventually it will ferment out.
No. Wrong.
Read my previous. Read about Keeving. Read anything at all about basic biology.
Yeast needs more than sugar. Yeast will stop fermenting when it runs out of ANY of it's limiting factors. It is not at that point dead. Further, yeast can (and do) create buds (like spores) which are really quite resistant to environmental factors. So while you may not have ACTIVE yeast you can still have VIABLE yeast which is NOT fermenting and will not ferment until the conditions are right for it so to do.
Rate for fermentation can be limited down to effectively zero by one or more factors:
- Temperature (both high and low)
- Fermentable sugar concentration (both high and low)
- Other nutrients (usually Nitrogenous chemicals and metals)
Combining these factors can stop a fermentation happily. Not kill the yeast but stop a fermentation. Once more, I'll return to keeving. The concept here is that the nutrient level is reduced such that the yeast can only process sugar down to a certain concentration, after that it just can't get it into the cell to be used, because it needs the other nutrients for that process. Add more sugar, you get more fermentation. But still down to that sweet FG. Add more nutrient and it will ferment out to dry.
THAT is a stuck ferment. THAT is why one, some or all of the techniques we use to start them up again work.
My thoughts toochrig said:For a second there I thought you wanted a discusion... Don't feed the troll. :lol:
johnnyboy1965 said:Sorry 74..I cant count two of them
Do you honestly think that I am incapable of using a search engine...thank you for pointing me in the right directioncalumscott said:Tell you what, I'll save you the trouble of a google:
http://scholar.google.co.uk/scholar?q=f ... CCwQgQMwAA
johnnyboy1965 said:I gave my educated opinion
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