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View Full Version : Safe useful life for dry yeast


msk
04-24-2006, 11:05 PM
I just visited an old buddy and snagged up his home brewing supplies [ale pail, bottling bucket, carboys, corny's, pots, recepie books, extracts]. In the piles were a couple exceptionally old extract bags and canned kits [from the years 1998-2000 accodring to the 'best when used by' dates]

The british pale malt dry extract was not rock hard, so it looked useable and tasty [it is fermenting now with fresh SAF-33, fresh hops, and a rock hard pound of amber DME that dissolved]. I opened some 'extra pale' LME that was black and smelled of molases. . . I suspect that it was not originally that color [it was all in a garage for 5 years or so, going from 20 degrees to 100 degrees F over the course of a year]

As for the yeast, it came with canned brown and canned smoked ale kits. I rehydrated the yeast that came with the brown, and I tossed in a teaspoon of sugar, and to my disappointment, it formed a karusen [disappointing because now I wonder if it is safe and now I refuse to throw it away]

Would a foil pack of yeast that suffered garage-syndrome for 5-7 years be safe? Something in there is alive. . . I just wonder what

guildofevil
04-25-2006, 05:15 AM
I'd probably use it, but then I'm a devil may care sort.

Seriously though. Yeast is cheap. Why risk ruining a batch of beer over a sachet of dried yeast?

Séan

rougetrout
04-25-2006, 05:25 AM
Well there are probably some live yeast in there. Dry yeast form spores which are very stable. The spores have good temperature resistance and can survive for many years. You may want to pitch a starter of the yeast due to low viable spore count but I bet you would find live yeast....of course for all that trouble why not make sure you have good yeast by buying new.

Best by dates are only the manufactures opinion right???

msk
04-25-2006, 08:44 AM
Good point, buy new yeast instead of gambling on disappointment with half of a day of cleaning and brewing. Thanks for waking me up