Dry Yeast Splitting / Storing

[pianobrew]

I am planning on making a one gallon batch of cider this week. I will be using dry yeast. Could I hydrate the whole package then use 1/5 of that "starter" and then keep the rest in the fridge for the future? If so, how long will those yeast stay viable?

 

[broadbill]

I think a better way to do it is to measure out (by weight) the amount of yeast you would need for the 1 gallon, then seal up the package and store it in the refrigerator.

 

[pianobrew]

Would the yeast really be better off in a make-shift closed package than in a sterile closed water environment?

 

[broadbill]

Would the yeast really be better off in a make-shift closed package than in a sterile closed water environment?

yes. Contamination is not the issue here, it is the viability of dried vs. reconstituted yeast.

Viability of live yeast cultures pretty decreases pretty uniformly (something like 15%/month IIRC--this % is from playing with the Mr. Malty website). In contract, freeze-dried cultures will be good for as long as the package expiration date states...typically years (and maybe longer).

In addition, the ideal procedure for dried yeast is reconstitute then pitch into wort fairly quickly. My guess is that stress of freeze drying is overcome somewhat but putting them into a "rich" media like beer wort. If left in plain ol' water (where there are no nutrients) directly from the reconstitution step I would guess the the decrease in viability would be even more severe.

 

[pianobrew]

Gotcha. Thanks for the thorough answer. Should I cut off the top of the package and eyeball how much to pour and roll it up and seal with rubber bands. Does this sound like a good idea?

 

[broadbill]

Gotcha. Thanks for the thorough answer. Should I cut off the top of the package and eyeball how much to pour and roll it up and seal with rubber bands. Does this sound like a good idea?

yup, that sounds good. I'd probably just add about 1/2 the package and save the other half. You'll go crazy trying to eyeball 1/5 of a pkg.

 

[TheMan]

Do you happen to have a small scale? This is obviously the ideal way to split it.

 

[pianobrew]

I have a digital scale that does grams. I guess I could measure out water and add 3 grams of yeast then pitch

 

[gyst]

This is exactly what I do for my 1 gallon dry yeast batches. Before I got the scale, I eyeballed half the pack (note - if you do this, USE A BLOW OFF TUBE), but now that I have a good kitchen scale, I weight out 3-4 grams, fold down and clip closed the yeast pack with a paper clip, put it into a plastic baggie and remove as much air as possible, date it, then throw it back in the frig. If its less than a year, I feel free to dip back into the yeast for another batch - after a year, I suck it up, spend the $3, and repurchase.

edited to note - and obviously, a year isn't a hard guide - if it expires, I chuck it.