Harvesting yeast

Question

I just finished with my first brew and have collected the stuff left at the bottom of the primary in a well sanitized jar. 24 hours after in the refrigerator it has separated into two layers. One of them is a liquid on top and below it is a white residue.

After checking multiple sites I am confused as some say that the yeast is in the liquid and others say that it is in the white stuff.

Could anyone help me here. I really need to save yeast as it just isn't available here and I'll need to have someone coming back from the US to order new yeast.

Thanks a million.

Answer 1

There are no doubt yeast cells throughout it, but if you're going to pitch from that, you should use the topmost white stuff below the liquid. All of the slurry below the liquid should be fine, but you'll have a little more trub settled down at the bottom. And since you'll only need to pitch a bit of this in the next batch (assuming you're not jumping up to a much larger batch), you might as well use the best stuff.

If I were you, I would:

• store this in the fridge
• on brew day, take it out and let it sit at room temperature for a few hours
• when you're ready to pitch, pour off the liquid off the top, and then pitch about a third (from the top) of what remains.

Answer 2

There are yeast cells in all volume. Very little of them in liquid, a lot in settled down layer. More on the top.

If you only need to wait a week or so, just discard the liquid and pitch. If you need to wait longer, I would strongly suggest making a sterter.

Starter or not, I would suggest you to take jar out of the fridge day before use, swirl it to make content homogeneous, and put in fridge again. That way, when yeast cells will settle down again, you should see 3 layers. Liquid, bright live yeast, and darker dead yeast. If so, of course use only the middle layer. But if you can see only two, that's OK, too. Discard liquid and use what's left, take from the top how much you need.

Answer 3

The healthiest yeast tends to settle last. The process you need to read up on is yeast 'washing'. Here's the quick method I use.

• It's important to use sterile jars, flasks, water.
• Once your trub is well settled like in your pitcure, decant the liquid off.
• Add sterile water to the jar and mix by shaking.
• Allow to settle for just a few minutes.
• Decant the remaining liquid to a new jar and refrigerate. This liquid will contain the healthiest washed yeast.
• This process can be repeated as much as you want to wash and harvest more yeast from the trub.
• You can then decant and combine the yeast for storage. I add a little nutrients at this point.

Answer 4

Decant the liquid, as it contains the healthiest purest mix of yeast cells. I'd mix it with sugar and yeast nutrient, shake to aerate it and leave sealed at room temperature for the yeast cells to multiply; for about a week or so. Then refrigerate till it's next needed. Adding a campden tablet will help prevent risk of other microbes ruining your culture.