Should I discard the yeast in my fermenters? By this stage of the restrictions you may be wondering if residual beer in fermenter is worth keeping. Depending on the style and strength this is a debatable point and a difficult decision. Strong beers and dark beers will be longer lasting so certainly worth monitoring to judge their quality. If well chilled many will last weeks yet.

What of their yeast? Well it is certainly worth reducing the amount of yeast in contact with the beer to minimise flavour taints. The older the yeast the more cells will die and the more yeast bite they will release into the beer. This will be more prevalent in the layer of beer just above the yeast and although there don’t seem to be analyses of this it is likely that the casks racked off first will have a harsher character than those racked later.

Running the bulk of the yeast out of a conical will help in keeping quality so your beer will remain more stable. But what about the yeast? It won’t be in much of a condition for another brew but it may still be worth considering for other uses such as bread making.

Now or course bread does have its own yeast – strains of Saccharomyces cerevisiae with ability to rapidly evolve carbon dioxide in the matrix of dough. These are similar to brewing yeast but selected to be resistant to the high osmotic conditions of dough and to have a rapid start to their fermentation so as to quickly produce carbon dioxide in leavening.

With increased interest in home baking shortages of yeast have been reported so could your brewing yeast substitute? It’s worth a try although with some cautions. Brewing yeast is unlikely to work as quickly as dried baking yeast and may not rise the dough as strongly. However, on the positive side it is likely to provide distinctive flavours and produce interesting bread.

Advice would be to keep the yeast in a fridge until needed to minimise deterioration. Rather than mix directly into the full dough recipe incorporate your slurry in the liquid of the bread recipe, add say a third of the flour in a bowl and keep warm, if possible, around 25 – 30oC until it shows some frothy activity. Now blend in the remainder of the four, oil, salt and other flavourings and kneed to a dough. Leave this to rise, ideally to double in volume. This is likely to take longer than normal bread dough, possibly overnight, but when risen knock back lightly and separate into small buns on a baking tray. When risen again bake at 180-200oC / Gas 5-6 until golden – 30 mins or so.

Keeping temperatures may be difficult, particularly during the rising stages and lager yeast may be best choice as will work at low temperatures. However, brewing yeasts will differ and are worth experimenting with.

If you do find success it may be useful to advertise you have yeast available for local supply, perhaps contact a food outlet to add to their provision. May also be worth experimenting with adding some malted barley into the bread flour. Full crushed malt is likely to be too coarse but if you can sieve out the flour it could be added as up to a 20-25% proportion. With wheat flour in difficult supply this could be a useful social contribution to your local community. If you can’t supply beer, you might give your customers some bread.

Written by Dr Keith Thomas
Brewlab Director

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