Yeast Harvest

[Damien]

Folks--

What is your technique to harvest and repitch yeast? FYI: I have 15 bbl conical fermenters and use SAFALE S-56 yeast. Presently, I pitch new yeast every time but want to begin harvesting.

My plan:

Attach a sanitary hose to the bottom of the FV.
Remove the trub and watch for the color change.
Taste the slurry until it is no longer "bitter".
Look for a consistent color and creamy texture.
Smell it looking for a "nice" healthykindofyeast smell.
Fill a 5 gallon sanitary corny keg.
Store in the cooler until use (vent daily).
Use within 1 week or repitch immediately.

Questions:

Do you consistently take a sample and count cells with a hemacytometer?

Armed with an accurate count do you then calculate the required volume and pitch as appropriate?

Do you simply pitch the same volume, like 5 gallons for example?

If you were to repitch immediately would you then pitch cone-to-cone?

If so, how do you "measure" volume? Do you use a time hack?

Thanks again folks!

Damien

[gitchegumee]

Your plan sounds like a good one. In my experience, the yeast almost always taste bitter. I use a hemocytometer for each beer type and get a count per unit volume. I then pitch about 10 x 10^6/ml the first repitch and watch for proper fermentation characteristics--like lag time, fermetation time, fermentation flavor profile, and terminal gravity. I then adjust the volume up or down a tad, and from then on I pitch according to volume. Try to minimize variables such as the time from crashing the fermenter, fermentation pressure, and other things that might change the yeast count/volume ratio. Cropping the yeast should become an important milestone in making a batch of beer. If I had a larger facility, I would have a technician wash and count the yeast every pitch. Good luck!

[lhall]

Isn't that a dry yeast? I have always heard not to repitch dry yeast due to a lack of glycogen reserves. If you get to a production point where you can brew at least every two weeks, switch to a liquid yeast such as Wyeast 1056 or the White labs equivalent.

In a 15 bbl tank, I would dump the first five gallons, and then collect 5-7 gallons of yeast slurry. Try not to hold it in the corny any longer than necessary, and keep it cold! Better than venting it periodically, fit it with a blow-off tube.

[Laughing Dog]

We use the same yeast as you, I started harvesting about 2 months ago using about the same methods as you are going to. We washed the yeast prior to pitching with a light OXINE mixture. After about 3 generations I noticed that this yeast no longer had the ability to process Diacetyl as it did when I first started (we changed nothing in the brew process), so went back to pitching new yeast, the diacetyl issue is gone. I am very happy with this yeast I see fermentation within 4-6 hours and plan on staying with the status Quo for now.

Fred Colby
Brewer
Laughing Dog Brewing

[Michael Murphy]

I use a simullar technique, It hasnt failed and the yeast has been used for many generations, In fact I just changed out the yeast because we got to 40 gens.

I use a 50 liter sankey, I had a 1.5" ferrel attached to the bottom side, I cut the tube off the keg valve to the very top, I clean the keg after use with a small sprayball inserted in the top of the keg and lay it on its side to the cip (I let the alka drain and follow with hot water).
When Im harvesting I attach a valve to the keg bottom, and a T with the T into the bottom of the FV, and a valve on the other end, I also put a keg tap on to which is left open the out and the gas in, I fill the keg up till it squirts with 80C+ water and let it sit for a while, I then close the valve to the keg and make the first bottom drain of the FV into the drain, once I see it looks fresh and like it should I then close the fv and drain the hot water out through the T, ( I can tilt the keg on its side leaving it all attached) Get all the water out, then I close the out valve and harvest through the T into the keg ( fill it slowly and it will eventually plop out the top of the keg).

I take off the keg from the fermenter and move it to the FV reciving the wort, I already have CIPed it and have another T piece at the bottom, I attach the keg with its T making a double T, I then flush it again with hot water through the heat exchanger.

After I have more than 3/4 of the wort cooled I use an O2 hose and blow it into the FV through the top of the keg (I have a cap to close off the beer out of the keg tap and a quick connect on the gas in)

I also tilt the keg or if its real thick let the wort flow into the keg and shake it and re-blow it in.

I have 50hl FVs and a BH of 25hl I always double batch, pitch in the first batch and aerate only the first batch. It works fine.

[gitchegumee]

I've repitched SAFEALE S-04 at least a dozen generations with great results. Yeast will refill their glycogen reserves upon the end of the fermentation. As long as they are cropped properly at the right time, you should have no trouble repitching dry yeasts. After rehydrating the first pitch and respiring/reproducing properly, I don't think anyone could tell whether the yeast was originally a liquid or a dried yeast. Maybe the "diminished glycogen reserves" is just a "recommendation" from the dry yeast sales folks.

[jrein]

Are you folks harvesting from the bottom valve on the cone, or the racking tube port?

[gitchegumee]

Jrein, Always the bottom of the cone. Never the racking tube. You want the thickest precipitate possible--not beer.