View Full Version : Halving Yeast

05-02-2012, 10:51 AM
Veeeery green newbie here. I've made one batch of JAO, which turned out very well (used grapefruit instead of orange) and am now ready to start my next recipe (something a little more advanced).
My issue is that my scavenged glass carboys are all on the small side (3 gallons), and I see a ton of 5-gallon recipes I would love to try. While I know I can simply halve the other ingredients, I am unsure whether or not to halve the yeast. If I do, can I keep the remaining half in a bag in fridge for a month or two until I start another batch?
Thanks for your patience with my ignorance!

05-02-2012, 12:41 PM
You can just pitch the same amount that you would for a 5 gallon batch, especially if you have a high gravity must. If you are using dry yeast be sure to rehydrate according to instructions before pitching.

When you are ready to start your recipe be sure to post a brew log. And if you haven't already done so, take a look at the newbee guide in the yellow box to the left. There is a lot of good information there which will answer many of your questions.

Welcome to GOTMEAD and we look forward to seeing your progress!

05-02-2012, 12:43 PM
It sounds like you are using dry yeast and if that is the case at $1 a packet I don't see why you would want to since it is best to pitch a good amount of yeast to insure a healthy fermentation. Even when I make only a gallon batch I still pitch the whole 5 gram package (though if it is an 8 gram package I will split it in half for 1 gallon batches).

That being said you could split the package, but if you do I would definitely make a starter so that you're pitching a good amount of cells.

Chevette Girl
05-02-2012, 12:47 PM
Welcome to the forum!

I do the same as TAKeyser, I'll split packets for 1-gal batches (it'll last quite a while in the fridge) but I use a whole packet for a 3 gallon batch.

For all the rest of the ingredients, just keep the same proportions: either multiply by 3 for a 1-gal recipe or multiply by 3/5 if it's a 5 gallon recipe.

05-02-2012, 01:11 PM
Welcome AconyBelle

Thatís interesting, I have never split the yeast, even for a one gallon batch. Now do you two split your yeast because you can or because it's a good thing to do?

Nathan K
05-02-2012, 02:00 PM
Personally, I wouldn't split the packet because yeast is cheap and mead is already at a disadvantage due to lack of nutrients for good yeast reproduction. For 5 gallon batches, I actually use 3 packets.

All that said, I have never had a problem with storing open yeast. I've even read literature from yeast manufacturers that says you can do this. The yeast will lose it's viability a little bit faster once the packet is opened and you should make sure you push all of the air out of the packet and seal it with some tape. If I'm going to be doing a lot of fermenting with the same strain, I will buy a 500g package ($15 to $35 from most places, depending on the strain) which is equivalent to 100 yeast packets and I will use some, take the air out, reseal it, and put it back under refrigeration. I've never had a problem with that method.

Medsen Fey
05-02-2012, 02:17 PM
Keeping open yeast may allow bacterial contamination, but in most cases that won't be a problem especially if stored in a fridge.

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Chevette Girl
05-02-2012, 02:26 PM
That’s interesting, I have never split the yeast, even for a one gallon batch. Now do you two split your yeast because you can or because it's a good thing to do?

Nope, I do it 'cause I'm really cheap and I don't always have lots of all the different yeasts on hand and my LHBS doesn't always carry stock of things other than EC-1118 and K1V-1116. D47, RC212 and 71B aren't always easy to get a hold of for me and I'm not always so organized about starting a batch (they're often spontaneous because I suddenly have a harvest, a bargain, or need to make room in the freezer, so if I'm only doing a 1-gal batch, I'll split it.