yeast havesting from horizontal lager tank

[Richard Pivo]

Hey all,
we are in the process of converting a 600gal horizontal oval shaped dairy bulk tank into a lager tank for our flagship pilsner. the tank came with a 2"T.C. port on the very bottom of one of the flat ends and we are planning to install a racking arm directly above that for drawing off clear beer. my question is how to best harvest a pitch of yeast off of a tank like this? I am currently using converted 1/2bbl kegs (cellar kegs from GWKent) as yeast brinks which work great for our 15bbl conical f.v.s but I was hoping to get some tips about drawing the yeast off a flat bottomed vessel into a brink without just lifting one side with a forklift (sketch).

it has been suggested to leave the cake in the fv and k.o. fresh wort of the same beer onto it. but this seems like lazy brewing to me, especially because I intent to re pitch up to 8 or 9 times.
any experience with horizontal fvs would be appreciated.

cheers!

[swright83]

Our brewery used to have a couple of 30 bbl horizontal tanks, and we were never able to get a pitchable amount of yeast out of the bottom. I don't know how many conical tanks you have, but you'd be better off harvesting yeast from a conical into a freshly cleaned and sanitized tank, then transfer the beer into the horizontal. The yeast would also be healthier if harvested closer to when it finished fermenting, rather than waiting for the beer to drop bright.

As for the forklift "tilt" you mentioned, we had 12" or so pieces of I beam on the feet on the side away from the racking arm, so there was a slight tilt so that we could recover more beer. I would strongly advise against using a forklift. For the yeast to really settle on the racking arm side, you'd have to leave the forklift in place for days, maybe weeks. Also, it could slide off and ruin the beer and the tank, and possibly other equipment you have stored around it.

[UnFermentable]

Know a guy who has a number of horizontal fermenters and he has the same issues as swright83. He is only a 3HL, and the tanks have manway openings on the side, so he gets a clean hoe and gloves and rakes the yeast into a pile where he can scoop it into the brink. He is serving from the tanks as well, so its a real uni-tank. Ferment, crash and then serve all in one shot. This means he is harvesting yeast that has been in the tank a long time, and probably brings some autolyzed yeast and lots of old/low viability cells. The dairy tank provides some challenges as it probably doesn't have a great manway.

If you have only one horizontal tank, you may face issues seeing 8 or 9 generations with lager. Your yeast will not be very healthy if harvesting at the very end of conditioning, and harvesting at high krausen will be difficult. If you can't pitch your yeast quickly (because you are waiting for conditioning) then you will loose viability and get autolyzing. You are better off looking into propagation over the efforts required for harvesting from a horizontal, IMHO. More consistent and repeatable.

Before going the forklift route, I would look at a 5 ton chain hoist if you have a sling loop on one end. I personally still wouldn't like this whole idea, but at least a bit more fixed and keeps your forklift open.

Most horizontal tanks are used for lagering in my experience, with primary occurring in one vessel and then transferring to the horizontal for long term conditioning. This would be my vote. Pitching yeast would be removed prior to transfer. I would also be concerned about the CIP of a horizontal used as a fermenter. You will have a lot of dried gunk towards the top and I would be concerned about getting the far corners clean without hopping inside (no pun intended). Cold beer doesn't require quite as much effort to clean properly.

Let us know what you settle on. I'd be curious if you go the forklift/hoist route but it seems dangerous to me.

[Swags]

harvesting yeast from lager tanks

We have two 30- 40 bbl. lager tanks and I have successfully harvested yeast a few times. Though we don't do it on a regular basis.

We have a size huge stainless steel "Hoe" that has a curved bottom end to match the bottom of the tank. The blade is about 20" across and 10" high in the center. I have a 1" diameter stainless tube about 7' long that attaches to the hoe with a SS threaded coupler. Redneck I know, but it will pull the yeast to the bottom drain, then collect in a bucket or stainless container of your choice.

Good luck!

[KennyD]

yeast rake

Brewed with 450bbl horizontal lager fermenters for 8 years, we started raking the yeast into a yeast brink using a pump to collect, cleaned and sanitized the fermenter then pumped the healthy yeast back with the chilled wort. The yeast was checked in the lab before pitching and after acid wash if needed. However we did have a centrifuge so we decided to harvest from that, very easy and no raking. I do love them centrifuges no more DE