Acid washing..how long?

I'm going to attempt acid washing of a yeast cake from a previous batch. How long *can* I leave the yeast in the low pH environment? In other words, if I do a normal wash/harvest like in the "yeast washing illustrated" thread, but instead use pH 2.5 water to add to the cake before putting it in jars, do I later have to let the yeast settle in the jars, and wash the contents of each with more neutral water before storing in the fridge?

I would. How long are you planning on storage?

I've harvested enough for (3) additional batches. It'll probably be stored for ~1.5mo. In all the tek's I've read, there's no mention of pH adjustments, but usually the yeast is utilized within hours.

GNBrews said:

I've harvested enough for (3) additional batches. It'll probably be stored for ~1.5mo. In all the tek's I've read, there's no mention of pH adjustments, but usually the yeast is utilized within hours.

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Well if your only going to store it for 6 weeks I don't think you need to "WASH" it. You can there is no doubt about that, but what a lot of us do here is just do a "CLEAN" transfer from the primary. where you used sanitized water and dump that into your carboy after your transfer, let it set for like 5-7 min and pour that into your mason jars. There is a thread here on how to do it. I have been doing it for years and love the method myself. Now if you were going to store it much longer, say 3-5+ months I would recommend an acid wash sure. But even then I wouldn't store your yeast in a 2.5 ph solution for that long. But thats just me.
JJ

Just wash it with water. I keep yeast in the fridge like that for a couple of months with no problem. See if you can find a used mini-fridge and use it exclusively for yeast. I keep mine around 36 degrees F. A few days before you need it just pull it out, pour off as much of the liquid as you can without losing too much yeast and add a starter made with 1/2 cup of the cheapest DME you can find and a pint of water. Repeat that process again when you start your mash and you should have a really active starter ready to go. I try to pitch between a quart and a half gallon depending on the OG of the beer I'm brewing. Your bucket will be off to the races in a few hours!!! My philosophy is that the faster and the more yeast you have in your wort the less you have to worry about anything else contaminating it. I just finished removing the airlock and installing a blowoff tube on a hefeweizen I finished brewing at 4 am last night as it was already starting to overflow the bucket less than 24 hours after being pitched.

I'm not sure you should store it very long at such low pH. According to this website, they used an acid wash for 2 hours, and viability went down on one of the two strains from 98% to 84%.