Yeast Harvesting, Propagation, and Storage Methods for Smaller Breweries ?

[Scarum]

Does anyone have an SOP or any info on Yeast Harvesting, Propagation, and Storage Methods they would be willing to share? We of course do cone-to-cone as much as possible and when we are not able to we harvest into five gallon buckets with airlocks. We hold the yeast in our walk-in for no more than a week and have been able to maintain good cell counts and viability above 85%. However, we have double our production this year to 5000bbls and with three different house strains using buckets is getting cumbersome. I purchased two 1/2bbl yeast prop kegs from GW Kent to try on one of our higher volume strains and have modified them so we can use them as storage and propagation kegs. I built a manifold to allow for sanitary aeration of the slurry and addition of wort. They have definitely improved things, but I do have some specific questions. My primary concern is getting accurate cell counts. The air/wort-in tube goes to the bottom of the keg and I’m sure creates some agitation but samples are still pretty thick (even with a little tilt and shake action). I’ve had others recommend storage in conicals and have see this method used at quite a few breweries, but seems that would produce the same issues. Without the use of an agitator, whats the best method for getting a homogeneous sample? Any other advice and recommendations will be appreciated. Cheers!

Kade Miller
Head Brewer/QC/Maint.
Avondale Brewing Co.
Birmingham, AL
251-654-2309
kade@avondalebrewing.com

[kererubrewing]

We use 0.5BBL SS conicals to store our yeast with good success. Experience has shown what the ideal harvest volumes are for different strains of yeast where we do cell counts from the FV after pitching.

[brewgood]

Cell count in yeast brink

After the yeast is settled into a brink obtaining an accurate cell count can only be achieved after you mix the yeast to create a homogeneous blend of the yeast. Pumping the yeast bottom to top will work. You can use the same pump - a peristaltic pump (see Verderflex pumps, www.verder-us.com) - to collect and inject the yeast.
An optional approach is to weigh the yeast + brink to estimate contents which with trial and error can give a good estimate of the total yeast volume. You can also dose the yeast by weight with the peristaltic pump either cone to cone or from the brink to cone or KO line injection point. Weigh a beginning and ending sample of the yeast to estimate weight of yeast transferred and correlate that number with your post-pitch cell count. Dream of a Coulter Counter or Mass Flow Meter, only $30,000.

[CharlosCarlies]

We also do our counts/pitch by weight (thanks metric system!), but as far as your main question about getting a homogenous sample, we use small 22g conicals and have had similar issues. When we were a one man show and not brewing nearly as often, I used to be diligent about swirling/shaking up the brink every day which seemed to help but still wasn't perfect.

I feel your pain though because many of our counts are showing fairly awful viability despite using best practices like feeding the yeast, pulling it as soon as possible, keeping it cold and re-pitching as soon as possible, etc. With that said, we got stuck last week when brewing our Doppelbock (which naturally takes a shit ton of yeast) and had to pitch what we had anyways despite really bad viability counts. Fermentation took off and is proceeding exactly how we would expect given our calculated pitch rate, so we're clearly not getting a very accurate sample. I can also tell when pushing the yeast into the fermentor because it's always super thick and flows incredibly slow until getting through the denser portions on the bottom.

[beerguy1]

i just finished taking a keg and put a 90 degree 1.5 into the side of the keg about 1" from the bottom of the keg it has a TC fitting on 1 end. Then removed the old spear put a 4" ferrule then a cap that reduced 4" to a 1.5 TC fitting. That big opening allows me to dump in dry yeast to make a starter or I draw from the cone into the keg. When it comes time to move the yeast to a tank simple 1.5 TC hose connections enter at the bottom it swirls thru the keg (thus the 90 elbow at the bottom) and out thru the top to the tank. Simple air lock with the starter and all seems to work great.

[RipRap]

i just finished taking a keg and put a 90 degree 1.5 into the side of the keg about 1" from the bottom of the keg it has a TC fitting on 1 end. Then removed the old spear put a 4" ferrule then a cap that reduced 4" to a 1.5 TC fitting. That big opening allows me to dump in dry yeast to make a starter or I draw from the cone into the keg. When it comes time to move the yeast to a tank simple 1.5 TC hose connections enter at the bottom it swirls thru the keg (thus the 90 elbow at the bottom) and out thru the top to the tank. Simple air lock with the starter and all seems to work great.

Any chance you have a picture of this?