Dry yeast propagation: an emergency measure...

[ThePasserby]

Greetings to you all brewing enthusiasts.

I'm currently considering starting propagating dry yeast packets, due to a chronic shortage in the country where I live.

I have read many similar threads on this and other forums, and the general consensus seems to be "Don't bother propagating dry yeast" due to many reasons. Problem is, there is simply no easy access to dry yeast packets down here (liquid yeast vials are pretty much out of the question) and I'm trying to increase my beer production. I'm currently brewing a pretty good American Pale Ale recipe.

The question is, then, how do you suggest I go at this? Is it viable to propagate dry yeast straight from a starter? Is collecting slurry perhaps a better way to go? And perhaps most importantly: How do I calculate the magical "million cell count" number from my cultures?

Please remember, I'm looking for this information as an emergency measure. I know it's not an optimal solution.

Thanks to everyone for your help.

 

[IslandLizard]

Of course you can make starters from dry yeast to propagate. Then store the slurries in well-sanitized or sterile jars or vials in a fridge. Depending on yeast strain and environment they'll keep 6 months to a year, but cell counts will diminish from day one.

Alternatively you can make a starter, save 1/4 to 1/2 for the next batch and pitch the rest. If you keep doing that you'll always have yeast. Plus you can reuse yeast after beer is racked off.

 

[dyqik]

The only reason people say to not bother propagating dry yeast is that it is too cheap and readily available for them. This doesn't apply to you, so go right ahead. At $6 a pack of US-05 from my LHBS, I propagate dry yeast occasionally.

Just rehydrate according to instructions and then pitch into a large starter to get your initial population - use some for a batch of beer, and save the rest. Then carry on in exactly the same way as for liquid yeast.

 

[flars]

The Brewers Friend calculator will give you the estimates of viable cells available and billions of cells propagated with various size starters. Take a look at the information below the calculator also.

http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/

 

[ThePasserby]

Thanks to everyone for the feedback. Went ahead and did it. Should have taken some pics for your future reference. I'm currently bottle-conditioning the beer, so in a couple of weeks I'll be able to tell you all the results.

On top of that, I collected the slurry from the fermenting carboys and kept it for future use.

 

[AnOldUR]

I'm currently considering starting propagating dry yeast packets, due to a chronic shortage in the country where I live.

What about dividing up a packet of dry yeast into, say five portions. Then use each portion to make a starter before your brewday. I'd think in it's dry state, the yeast would last much longer than a slurry.