Saving Partial Packets of Dry Yeast

I was thinking about giving US-05 a shot on my next batch so I went to MrMalty’s pitching rate calculator and it says I would need 1.3 packets of dry yeast. Now if I was using liquid yeast I would buy 1 pack of yeast and make a starter to hit my target pitching rate. But since you don’t make a starter with dry yeast I’m wondering if it’s possible to save an open packet? So bascially buy 2 packets and use 30% of the second packet, saving the rest for my next batch.

Given that a packet of US-05 is about half the cost of a Wyeast smack pack, this could be an easy way to save a couple bucks. But if I have to buy two packets every time I might as well just keep buying liquid yeast.

Anyone have any advice on if this is feasible? Any suggestions on how best to protect an opened packet?

The Fermentis data sheet specifies using an opened packet of yeast within seven days. I’m using bread yeast from a jar that was opened six months ago. I keep the bread yeast and my opened pack of SA-05 refrigerated. Like the bread yeast I will rehydrate the SA-05 to check for viability. I won’t keep the ale yeast as long though. Ruining a batch of beer is much more expensive than two loaves of bread that won’t rise.

Screw the 0.3 pack of dry yeast, and just pitch one pack. I can virtually guarantee that your beer will turn out just fine with just one pack.

That being said, I use partial packs a lot because I am a small batch brewer. I usually only make 1.7 to 2.5 gallons at a time, so then it’s a waste to use a whole pack for those. All I do is sanitize the pack as well as possible before opening, use a half pack or however much, then fold over the side a couple of times and tape it shut, and stuff it into the refrigerator. You can seal the sanitized packet in a Ziplock if you’re worried about contamination. It will keep just fine for several YEARS like that. Next time I need it, I take the tape off, pitch and roll. No need to weigh the yeast or anything like that. Just feel around how much yeast is in there, and estimate how much you need, sprinkle it out, and that’s good enough.

Dry yeast is awesome stuff. If I could, I would use dry yeast for everything. Unfortunately, I am also somewhat picky with my yeast choices so I do use a lot of liquid since there are so many dozens (hundreds??) of kinds available.

Friar Tuck’s right.

[quote=“dmtaylo2”]Screw the 0.3 pack of dry yeast, and just pitch one pack. I can virtually guarantee that your beer will turn out just fine with just one pack.

… You can seal the sanitized packet in a Ziplock if you’re worried about contamination. It will keep just fine for several YEARS like that. Next time I need it, I take the tape off, pitch and roll. [/quote]

Agreed, I’ve used one pack with some 1.075 beers, which is about where you should consider two packs, and they fermented just fine.

And thanks for that report on your success with saving it for years (weeks/months would be fine for me). I keep thinking about doing some small/split/experimental batches, and being able to divide a dry pack would be useful.

-kenc