Fermenting with yeast sequestered in dialysis tubing

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Fermenting with yeast sequestered in dialysis tubing

Quick turn around on a beer with minimal cloudiness was the goal. I brewed an ~5% ABV Saison on a Sunday, and served it on Friday – naturally carbed. As a scientist I know better than to change more than one variable but I did it anyway. First off, I fermented in a keg for the first time. I had a 5 psi pressure relief valve for the first 3 days, and then swapped it out for a 15 psi valve for the last two. So that allows me to ferment fast and carbonate, then next thing was how to deal with all of the yeast in suspension (I’m not a hefe-weizen fan). One could cold crash, but that takes extra time, especially when carbing naturally. My solution was to sequester the yeast inside of dialysis tubing. This is used in labs, typically when purifying proteins to do a buffer exchange. The membrane allows small molecules like salt, *sugars* and alcohol to freely pass, but most proteins are too big to pass through the membrane. So I reasoned that I could put the yeast inside and they would still have access to all of the sugars but then I wouldn’t have to deal with pouring a cloudy beer.

I brewed up an ~1.048 Saison and transferred it to a keg. I had autoclaved some dialysis tubing and then used a funnel to pour in a yeast slurry from a previous batch (it is like a sausage casing and comes in a variety of diameters – mine is a little bigger than hot dog size). I then tied it up and tossed it in the keg. I left quite a bit of room in the tubing to allow for expansion just in case. It worked just fine! Unfortunately my funneling and tying technique was not the best as some yeast got spilled on the outside so there was a little bit of yeast that ended up in direct contact with the wort so the final product was a little cloudy. I got home from work on Friday and put the keg on ice and tapped it 1 hr later. The keg was empty in a couple hours (summertime).

I need to try it again, but this time be more careful with my putting the yeast in the tubing to see if I can get a pretty clear, drinkable beer in just one week.

I wonder how well it would work to pull out the tubing after one week, and put it into a new batch?

I think if you recycle the

I think if you recycle the tubing for another batch you will need to leave quite a bit more room for cell replication.

Did you do any sort of stirring or swirling? I'd be worried about pockets of wort that may not have adequate contact with the yeast and you may therefore leave some residual sugar. Also, since the yeast is not mixed throughout the wort, I'm wondering if fermentation time may be longer. And lastly, I wonder if diacetyl or acetaldehyde is a concern if the wort isn't mixed in some way.

I think this is a great experiment, please keep us updated here. If this ends up working out, this may be an easy way to stop a beer short of full attenuation, by pulling the yeast when it gets to where you want. Even better, you could make sweet cider, wine & mead without sulfites.

No stirring was done, and I

No stirring was done, and I don't think it really is needed. Diffusion works pretty fast so I don't think you will have any pockets of wort with extra sugar. Think of how quick a drop of food coloring in a glass of water quickly and uniformly tints the whole solution, even without any stirring.

There still will be some mixing, as the yeast still will be releasing CO2 and this will rise, creating a current in the wort.

It is actually a bit tricky to load the yeast in the tubing without having any "escape" If you use a funnel, you have to be careful as you pull it out, to not touch the sides of the tubing (like the old kids game operation), other wise this can lead to some yeast outside of the tubing when you seal it up.

could you not rinse the tube

could you not rinse the tube after tying with boiled cooled water? have a bucket ready and give the closed tube a little dunk? cool idea though. I have a friend that can't do yeast and if what you are saying is true then you should end up with similar yeast levels to a heavily filtered beer.

"Remember, kids, the Only difference between screwing around and science is writing it down." - A. Savage

I think it would be hard to

I think it would be hard to rinse all of the yeast off if some spilled, so you might get a little yeast growing outside the membrane. Next time I try this, I'll skrunch some of the tubing onto the funnel like it was a sausage stuffer. Then once the yeast is loaded, I can pull extra tubing down off the funnel to give me a clean area to tie the knot.

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This discussion made me think

This discussion made me think of this.....


Life begins at 60....1.060, that is!