yeast harvest temp

[barleyfreak]

I've been following what a lot of brewers are doing regarding a soft crash for any pre dry hopped beers (to 50 or 55 depending on strain). I've been actually doing this with all my beers -- I drop to 55 after two days at TG (at ~68 deg), leave at 55 for two days and harvest on the 2nd day. If it is to be dry hopped, I do so, and let it rise over the next week or so. If no dry hop, I then crash to 34, after harvest.

Question is for the non dry hopped beers, would I be better served crashing all the way to 35-40 and then harvest, or is 55 aok? I know wyeast suggests the lower temps, but I'm wondering what is being practiced out there most for non dry hopped beer harvests?

[NHBrewer23]

According to the Yeast book published by the Brewers Association, the optimal time to harvest yeast is when the target gravity is reached but before the diacetyl rest. This would mean harvesting at your 68 degrees. I have collected yeast at fermentation temperature before and what I found was that my yeast cell counts were much lower than a crashed beer. This required me to collect and pitch a greater volume into the next beer. I didn't care for this too much as I didn't want to risk any flavor carryover.

For dry hopped beers, I typically crash to 60 for a day. This allows enough yeast to flocculate while still providing me the warmer temperatures for the dry hops. For all other beers, I just crash to 32-33 and collect once at temperature.

[barleyfreak]

Thanks. Falling into the "if it ain't broke..." category, I'm tempted to just keep harvesting at ~50 degrees for all beers. But maybe I'll try one at 35 degrees and see if I can see any difference at all in subsequent ferments.

[Bainbridge]

FWIW we typically harvest off beer that's been crashed to 35 at the end of fermentation and had a day to settle, sometimes two if it's being unflocculant. If it's a dryhopped beer, we crash to 60, harvest, dryhop. But we try not to harvest off dryhopped beers usually, since ours tend to be higher gravity anyway. We tend to get high viability but lower cell counts overall, as mentioned above. But we've gone cone to cone off our IPA (dropped to 60, but pre-dryhop) and it's works like a treat.

[Junkyard]

I'm a strong advocate of crashing slightly to harvest. If your fermentation is done and the yeast are still in suspension it doesn't take much to get them to fall out. Sometimes for us it's only a matter of going from 72 to 65 degrees overnight and we have plenty of yeast to harvest. The key is just harvesting yeast slowly and carefully.

[Crosley]

Junkyard, can you elaborate on "slowly and carefully"
I am on a 3bbl system and harvest into 1 gallon containers. I agree that my harvest technique could be slower but not sure the best way into small containers.

[barleyfreak]

I harvest into 1 gallon containers as well and as I said, always at ~50-55 degrees. Slowly for me is just not opening the valve full as I fill each container.

[NHBrewer23]

I try to harvest using counter-pressure to control the flowrate. Throttling with a butterfly valve will prevent the more dense slurry from entering the container and will shoot the more liquid slurry. Can't really be healthy for the yeast cells.

I use a GWKent keg for collecting yeast. I will typically pressurize the keg with a few pounds of CO2 pressure. The amount depends upon how much pressure is already in the fermenter plus the hydrostatic pressure caused by the column of beer above the bottom port. I will then open the bottom valve on the fermenter all the way and allow the yeast to enter into the keg at an even pace. I will then slowly vent the keg to allow the keg to fill until I have collected the weight that I need.

[barleyfreak]

Throttling with a butterfly valve will prevent the more dense slurry from entering the container and will shoot the more liquid slurry.

I did not know this. I had it backwards. I thought a more open valve meant more chance of beer punching a hole through the yeast.

[NHBrewer23]

It will certainly punch a hole if you allow the yeast to flow too fast. Using counter-pressure I try to fill at a rate of a lbs. every 2-3 seconds.

[Junkyard]

I use a Homebrew stainless conical as a yeast brink, it is pressurizable for yeast transfers and really works slick. Having a yeast brink is more conducive to collecting yeast slowly because once the connection is made, you dont have to worry about harvesting enough yeast in one pull.

I usually connect my brink and collect small amounts of yeast every 5 minutes or so until I have my full 5 gallons, which usually takes about 30 min to 1 hour. I'll just come back to it as I'm doing something else. Then you allow the yeast to collapse back on itself because yeast tunneling is pretty much going to happen no matter what.

[Crosley]

Maybe this is a stupid idea but my plan was to make some sort of yeast harvesting container out of a 5 gallon plastic homebrew carboy. I don't know yet but some sort of bottom inlet and a pressure relief top outlet???

[Junkyard]

That may work fine. I would personally want something I could heat sanitize. And something that wouldn't scratch at all. How were you planning to pitch the correct amount of yeast once harvested in a plastic carboy?

The other method we use to harvest yeast is with 5000Ml Erlenmeyer flasks, they are borosilicate so they can be heat sanitized with boiling water. I have to harvest into 2 erlenmeyers for a 3bbl batch and it's more difficult to harvest slowly enough to avoid yeast tunneling. But they are easy to swirl up and pitch through the top manway.

[woohokie]

We always harvest at fermentation temp after capping the tank at the tail end of primary to hit 5psi or so. We fill a converted keg yeast brink under counterpressure. Super slow flow rate. Usually see 50% solids of a sample after refrigeration when using a highly flocculant dry english ale strain.

[GritCity]

That may work fine. I would personally want something I could heat sanitize. And something that wouldn't scratch at all. How were you planning to pitch the correct amount of yeast once harvested in a plastic carboy?

The other method we use to harvest yeast is with 5000Ml Erlenmeyer flasks, they are borosilicate so they can be heat sanitized with boiling water. I have to harvest into 2 erlenmeyers for a 3bbl batch and it's more difficult to harvest slowly enough to avoid yeast tunneling. But they are easy to swirl up and pitch through the top manway.

Hey Junkyard,

If you are using a stainless conical, I have a question about your re-pitch. How do you know how much you are re-pitching in a 3bbl tank if you have (x) gallons of solids and you only need to pitch a fraction of that? I like the idea of a corny or small conical as a brink but wasn't sure how to deal with the volume.