Yeast Harvesting Timeline

So last night I bottled a batch right from the primary fermenter. I ran out of motivation to attempt to harvest the yeast, and just left it in the primary. Is it too late to save it? I mean, does harvesting the yeast have to be done right away, or is it okay for the cake to sit there a few days?

The yeast can be harvested a few days later. There is much less risk of contamination if the yeast has been covered by beer remaining in the primary. Being covered by a little beer is the same as being covered by a lot of beer as in an extended primary time.

The risk of contamination is greatly reduced by harvesting sooner than later.

Were you planning to add boiled and cooled water to swirl the trub and yeast into to begin the rinsing/harvest process? Much simpler to just swirl the trub an yeast, let sit 15 to 20 minutes while you do some clean up and then pour into a quart jar.

I did leave about 1/8 inch of beer on the yeast. I did also put the airlock back on. I’m not sure what process I’ll do precisely to harvest the yeast. This will be my first attempt.

You’re saying the yeast and excess will separate without adding water?

This is my first yeast rinsing using the boiled and cooled water method. WY 1056 from a a five gallon brew of American Amber Ale.


I felt I was spending to much time handling and exposing the yeast to possible contamination.

Second and third pictures are the results of just pouring a quart from the primary fermentor. These two pictures were from a five gallon batch of Dead Ringer. DR was dry hopped in the primary. Picture right after pour into a quart jar and then two weeks later after refrigeration.


I do strain hop material on the initial pour into the primary. I have been estimating 2 billion cells per ml for harvested yeast. I think I could go 3 billion. I will have the carboy on its side before the pour until I see a clear line appearing at the top of the slurry. About 20 minutes time. This allows some of the heavier hop debris and break material to settle out. Some of this will remain in the pour for yeast nutrient.

The result is about 375 to 400 milliliters of yeast slurry. Enough for three to four low to mid gravity brews.

I’ve since changed methods since my frig was getting overfilled with harvested yeast. Here is a quick synopsis.
Make an overly large starter.
Save some of the fresh yeast for the next starter. Pitch the main volume.
Make an overly large starter with the fresh yeast for the next brew and save some of the yeast for the next starter.
(If the yeast saved from an over built starter does not show signs of contamination when needed again, I dump the harvested yeast from the previous brew. Keeps the over build yeast saved and harvested yeast at a manageable volume on the frig shelf.)

Pitch rate/starter calculator with the overbuild calculator

I too have stopped the boiled water rinsing. From my understanding with rinsing you’ll never remove enough nutrients to make the yeast go dormant. It also increases risk of contamination. The risk outweighs the reward.

I do save fresh from the starter with ale and will get up to 10 uses and not any detection off flavors. I am about to brew my last lager for the season with yeast I saved from the primary… Close to 3/4 of a gallon, mixed with some trub. Doppel bock today! 8 gallons worth… Sneezles61