Scimming the head for reuse

[OldThumper]

Hi all,

Just a quickie:

Can I scim the head of my currently fermenting beer and save this in a sterilised container (placed in the fridge) for use as a starter for my subsequent AG brew next week? e.g. keep it in the fridge for 2/3 days and then activate it with the wort from my next brew on monday? I have read that people use the sediment at the bottom of the bucket at the end of fermentation but how about the frothy head 2 days in to fermentation?

Thanks

[Stonechat]

If you are using a live brewery yeast that is a true top fermenter, the answer is yes. I am using 6th generation Ringwood yeast to ferment an ale now and will skim the head in order to harvest about 130g of it to use on a brew on Monday.

I prefer to wait until the 3rd or 4th day of fermentation, by which time the yeast head is quite thick and creamy. I harvest by skimming the whole head with a sterilised slotted spoon and putting it into a sterilised pot. I give it a whisk until it's like a smooth mousse and pour the 130g of yeast barm into a sterilised kilner jar that is stood on top of a pre-tared set of scales. Then into the back of a fridge until next week.

With the yeast head removed I then rack the beer into a closed secondary FV for mst of the remaining yeast to drop to the bottom before kegging. By waiting another day or two the yeast will have got to a couple of points of final gravity and these are reached in the secondary FV.

I would not bother doing this with dried yeast as they are cheap enough to use fresh for each brew.

[OldThumper]

Thanks stonechat! Yep, the yeast if a live bewers yeast.

I assume it does not matter what type of beer I make next? For example, if the ABV of the next brew is say 4% rather than 5% it makes no difference to productivity of the yeast during fermentation.

Also, from what I gather you cannot continue to do this repitching as after a certain generation the yeast becomes unproductive.

[Stonechat]

The point about changing the type of beer may have some relevance. A more scientifically JBK brewer might clarify. Nearly all the beers I brew using live yeast are between 4% and 5%.

I kept a live brewery yeast going for 60 generations. This was a Worthington "B" strain and it was a one off as freshly obtained samples from the same brewery tended to lose their vitality after 12 generations.

I like the convenience and reliability of S-04, but a good top cropper does produce a more tasty beer.

[OldThumper]

Thanks Chris and Stonechat. I got the fresh yeast from the Flowerpots brewery which apparently use a yeast strain from the Ramsbury brewery (http://www.ramsburybrewery.com/index.html)

Sounds like it is always best to wait until as close as possible to fermentation complete before collection from the top.