Proofing dry yeast packets

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

skidaddytn

Well-Known Member
Joined
Nov 25, 2009
Messages
121
Reaction score
2
Location
knoxville, tn
For all those who proof their dry yeast before pitching, I have a question.... If there are no signs of life, do you pitch it anyway or immediately call the yeast bad and buy a new pack? I've done proofing 4-5 times now and always seen some form of activity (foam at the best, and small surface bubbling at the least)

My last packet failed to show any activity... it was no where near expiration date and I'm sure I did it right... I pitched it anyway and after 32 hours, I am seeing no activity in the wort... :-( I've never opened the carboy, but after 24 hours I swirled it vigorously by the neck to stir it up... after 48 hours I am planning on pitching a new yeast I guess.... The surface of the wort in my carboy looks smooth enough to see a reflection...
 
Most often you rehydrate the yeast, which in effect gives you proof that it is alive. By the end of the 30 minutes or so process if you don't see it active you can safely assume it is deadsville. I always have extra packets available when using dry, although I have yet to have a package not start actively foaming up after 30 minutes in 10 times it's weight in water (70F or so).

Get yourself some new packets and rehydrate and pitch.
 
you don't need to proof - yeast manufacturers don't recommend this, simply rehydrate. John Palmers online book is wrong and he corrected this in the third edition.
 
I've said before but I'm pretty certain the "proofing" practice is from the days when you'd get yeast off some store shelf that was taped in a box for god knows how long. I'd say the stuff at your LHBS in the fridge is likely pretty safe.

If it was me (noob givin advice alert) I'd let it sit for a bit and if it still doesn't show life toss in another packet.
 
Generally accepted dry yeast protocol: Don't Proof, Don't Make a Starter, Just rehydrate. Just passing it along, Jamil in his "14 Questions" at mrmalty.com:

"Another case where you generally don’t want to make a starter is with dry yeast. It is usually cheaper and easier to just buy more dry yeast than it would be to make a starter large enough for most dry yeast packs. Many experts suggest that placing dry yeasts in a starter would just deplete the reserves that the yeast manufacturer worked so hard to build into their product. For dry yeasts, just do a proper rehydration in tap water, do not make a starter."
 
Just to follow up... my yeast that failed the "proof" test is now active... After 48 hours it has finally developed a very small 2mm layer of kraussen... I am surprised it took this long given that I re-hydrated and the room temperature is at 74 degrees... many other dry yeasts that I've rehydrated and used have started in less than 12 hours...
 
The beer was a hefe and this particular yeast was Danstar Munich... The beer turned out ok... I do think that I needed to ferment it at a lower temperature, but it was the best I could do (its been hot over here lately)... when I get the $$ I will buy an old fridge and hack it into a fermentation chamber...

I do know about the nottingham recall... So far all of my nottingham has taken off like a rocket... Guess I've been lucky enough not to get a bad one...
 
Isn't proofing and rehydrating the same thing?

Proofing is adding the yeast to a small amount of sugar water (or wort) to see if the yeast are alive and active. Rehydrating is adding the yeast to plain water to re-hydrate the cells.
 
Back
Top