Gallon of yeast

So I was going to wash my yeast as described in the sticky thread but I ran out of time. So I racked my beer and added about 2 qts of water to the trub/yeast mixed it up and collected it all in a gallon jug and stored it in my fridge. So......now what? When I'm ready just decant the clear wort and separate into 3 or 4 smaller containers and store till I want to use one? How do I estimate the number of cells?

really? nothing??..................

I actually want to know how to know how many cells as well. As far as method, that is what i do as well.

From Mr. Malty:

"If you've brewed more than one batch, I'm sure you've noticed that there is a huge pile of yeast in the fermenter at the end. If (and that is a big 'if') you've got excellent sanitation all the way through the process and have provided proper yeast nutrition (including O2), you have a gold mine of healthy yeast ready to reuse. Of course, you don't want to reuse the whole thing. I know a number of people dump a new batch on top of the yeast cake, but you're not going to get the best beer that way. Yeast do need some growth to result in the right kind of ester profile, etc. While too big a pitch is better than too little, it is pretty easy to figure out how much you need and pitch just that.

There are about 4.5 billion yeast cells in 1 milliliter of yeast solids (solids with no excess liquid). According to Fix, in a slurry, only about 25% of the mass is yeast solids. Of course, if there is a lot of trub in there, you have an even lower percentage of yeast solids. The bad thing is that you can't tell how viable that yeast is, unless you have the equipment to properly test and count it. So this is where it gets a little bit like black magic. There are a number of factors that affect the viability of a given pitch of yeast. How old is the yeast? How stressful was their last fermentation? Have they had the proper environment and nutrients for successful reproduction or are they too scarred and tired to go on?

When the yeast is fresh and healthy off an previous batch, viability is maybe around 90%+. It goes down from there fairly quickly without proper storage and it also really depends on the strain of yeast. Unless you're going to get into testing viability, you're going to need to make some educated guesses and keep good notes on the results. This is where being a yeast psychic really helps. Start in a range of 80 to 90% viability and you probably won't be too far off. Use the Pitching Rate CalculatorTM to help figure out how much of that yeast you need. If your yeast viability is much lower than 90%, you should probably toss the yeast. If you really want to use it, you might consider pitching it in some starter wort to get the still viable cells active. When they're in solution, decant that active part of the starter into another vessel, hopefully leaving the dead cells behind."

The pitching rate calculator Jamil speaks of is at www.mrmalty.com

You are not storing washed (i.e. "rinsed") yeast, you are storing slurry and can expect its life expectancy to be shorter accordingly. I think your best bet is to either rinse the yeast properly, or use half a cup or maybe a cup of your slurry in a new batch in the next week or two, then rinse the resulting cake from that batch accordingly.

Or, if you are worried, just toss it. Yeast is relatively cheap, especially dry.

I have two one gallon jars in my frig right now. One each from two beers I racked 9 days ago.

I have a couple of quarts of water cooling. I boiled that water for about five minutes.

I will soon pour from each jar the beer layer on top. Once I begin to see the white cloud of yeast heading down the drain I will stop decanting.

I will then add some of the now cooled but boiled water to each jar. I will refrigerate it again and decant the beer once again.

Now, I will have sanitized some small canning jars and lids. I will decant the beer once more and begin pouring the yeast into the smaller jars.

As it is all the same yeast, I may, or, may not combine some of the jars to make space in my refrigerator.

I will then make a starter before I plan on using this yeast and follow Mr. Malty's recommendation for amount of slurry to pitch.

How much to use in the next beer? I find Mr. Malty too confusing and inaccurate when you are estimating yeast slurry. I have a simpler method.

As a general rule, the yeast cake at the end of fermentation will contain about 5 to 6 times the yeast required for the correct pitching rate. But we generally keep the yeast in the fermenter for longer, and the pressure iin the fermenter is not good for it, so I assume that when I harvest the yeast at about 2 to 3 weeks, I have roughly 4 times the amount of viable yeast required for a batch of the same size and gravity. Therefore if I brew a similar strength beer within a month of harvesting I will use one quarter of the harvested slurry (no starter required). You can use it washed or un-washed (I do both).

The amount of yeast you need is proportional to the gravity. If the next beer is twice the gravity, you need twice the yeast.

If the harvested yeast is over a month old, I will still use the same amount, but will make a starter, which will increase the yeast count and check viability.

Hope this helps.

Or you can use Mr. Malty and estimate yeast content, and solid content, and viability.

thanks everyone!