LandoLincoln
Well-Known Member
This is immoral. KEEP YEAST CELLS FREE-RANGE!
I find that reproductive activity seems to keep me healthy, but maybe that's just meThe yeast will definitely die at some point. Whether that happens after many batches or just a few, however, is still a very open question. But, properly handled, yeast can stay alive for quite some time. The fact that they're not reproducing actually means they'll stay healthy a lot longer.
I find that reproductive activity seems to keep me healthy, but maybe that's just me
So wait, if the yeast can't reproduce in these things, won't you just end up with dead yeast cells in a ball of goo? Or are their reproduction rates just hindered?
What prevents them from reproducing?
LandoLincoln said:This is immoral. KEEP YEAST CELLS FREE-RANGE!
Monday morning update: The beads are fermenting, but man-oh-man are they slow! The comparison here with the control fermentation is interesting.
The beads started fermenting very quickly. I pitched them on Friday night right before I went to bed, and they were already moving by the time I got up six hours later. It seems they've been chugging along at this rate -- but never any faster -- ever since. They've brought the wort down from 1.042 to 1.024 now after about 60 hours. Not terrible, certainly, but slower than I'd expected considering the pitching rate.
The control fermentation, on the other hand, showed no activity at all for roughly 24 hours but then managed to burn through all of the available fermentables by the time I got home from work yesterday (about 48 hours after pitching). This is consistent with what I'd expect for a healthy pitch of s04 in a low-gravity wort at 67º.
The relatively slower ferment of the beads isn't a problem per se, but it does make me curious. It should be fixable. To my mind, there are two possible bottlenecks here:
1) Wort contact - the beads are submerged but floating near the top. I don't suspect that sinking them in a tea strainer or the like would actually improve contact significantly, but mechanical agitation might. Giant stir plate?
2) Bead permeability - I'm going to mix up a few other test batches, perhaps with different ratios of alginate to yeast. I'm just guessing with so much of this, so I can't say for sure what will or won't make a difference.
Anyway, it's all moving along nicely! The bead beer is fermenting slower, but it's still quite clear so I suspect it will be ready more or less as soon as the yeast finishes fermentation.
Monday morning update: The beads are fermenting, but man-oh-man are they slow! The comparison here with the control fermentation is interesting.
The beads started fermenting very quickly. I pitched them on Friday night right before I went to bed, and they were already moving by the time I got up six hours later. It seems they've been chugging along at this rate -- but never any faster -- ever since. They've brought the wort down from 1.042 to 1.024 now after about 60 hours. Not terrible, certainly, but slower than I'd expected considering the pitching rate.
The control fermentation, on the other hand, showed no activity at all for roughly 24 hours but then managed to burn through all of the available fermentables by the time I got home from work yesterday (about 48 hours after pitching). This is consistent with what I'd expect for a healthy pitch of s04 in a low-gravity wort at 67º.
The relatively slower ferment of the beads isn't a problem per se, but it does make me curious. It should be fixable. To my mind, there are two possible bottlenecks here:
1) Wort contact - the beads are submerged but floating near the top. I don't suspect that sinking them in a tea strainer or the like would actually improve contact significantly, but mechanical agitation might. Giant stir plate?
2) Bead permeability - I'm going to mix up a few other test batches, perhaps with different ratios of alginate to yeast. I'm just guessing with so much of this, so I can't say for sure what will or won't make a difference.
Anyway, it's all moving along nicely! The bead beer is fermenting slower, but it's still quite clear so I suspect it will be ready more or less as soon as the yeast finishes fermentation.
Interesting stuff. The fermentation rates could also be explained by the inhibition of reproduction by the yeast being encapsulated by the beads. The control started slower because they were in a reproductive phase, but finished faster as there were now increased numbers of cells. In contrast, the bead started faster because they didn't have a stimulus to reproduce (i.e. fresh wort) but could not speed up the fermentation rate because their numbers are somewhat fixed (or decreasing, if you figure in cell death).
It would be interesting to do a cell count, but first you'd have to work out how to get the yeast separated from the balls first. Probably not worth the effort.
Thanks for the update.
I believe Mupor holds their's in a stainless cage under the wort. Here's a pic of what they propose to keep the beads submerged. Looks suspiciously like a strainer and something like a pizza cutter with the rim cut off.
I thought about trying this myself, but I'm not sure what the advantages are yet. Thanks for taking the reigns on this Malfet.
Hey, here's a crazy idea:
Think of a cake piping tools
Where instead of creating hundreds of "yeast balls" one creates one (or several) long star-shaped yeast-strings/snakes that can be easily fished out post fermentation.
I'll be buying the necessary tools to perform my own experiments.
Maybe even use food coloring in each "yeast-snake" to be able to distinguish between different yeasts/brett/lacto/pedio that will be fermenting the beer in question.
Now, who's with me?
You'd be losing a lot of surface area this way, which is trouble for diffusion rates. This stuff's actually pretty easy to work with. Dripping the beads into the calcium solution only takes a couple of minutes really, and I'll be able to fish the beads back out with not much more than a strainer at the end.
It would be really neat if the beads did ferment faster and allow the beer to clear in around 1.5 weeks instead of the 3 weeks that is often tossed around here as the minimum for primary fermentation. The time saving would have some value to me.
What about suspending some stainless steel shot or other weights inside the beads?
Any current visual pron available?
Thanks for the reply, it makes sense.
However, it was exactly the low(est) "surface area / volume ratio" property of spheres that made me think of a star shaped "yeast-string" to maximize surface area.
On the piping tool pic, look at the left table (pink) second top of the right column tool. I think it would be ideally shaped for such a task.
Of course, all I have to do convince myself is to do it.
I was thinking maybe 10cm long snakes (say 10 billion cells each) and if your recipe calls for 250B cells, you drop 25 of those bad boys in there and be done...
Hmmm....
I remember reading somewhere in Mupor's thread that you had to pitch as much bead-suspended yeast as you would end up with in a regular fermentation.
Thanks for the reply, it makes sense.
However, it was exactly the low(est) "surface area / volume ratio" property of spheres that made me think of a star shaped "yeast-string" to maximize surface area.
On the piping tool pic, look at the left table (pink) second top of the right column tool. I think it would be ideally shaped for such a task.
Of course, all I have to do convince myself is to do it.
I was thinking maybe 10cm long snakes (say 10 billion cells each) and if your recipe calls for 250B cells, you drop 25 of those bad boys in there and be done...
Hmmm....
Certainly...I like the color idea. Assuming these things keep for reasonably long periods of time and reasonably high numbers of batches (and I consider that a very big assumption at this point), it'd be nice to see beads of all different colors sitting in your fridge.
Just to clarify, though, a sphere only has the lowest surface area / volume ratio for a fixed quantity of substance. 10 grams of tiny spheres will have significantly more surface area than 10 grams rolled into a snake.
It would be beneficial to have "frills" on droplets, but I doubt you'd get that effect with a icing bag. Soon as the goop hits the calcium solution, its surface tension pulls it into a sphere shape pretty much no matter how it started. Worth a try, though!
One question that I am worrying about if this works: What about lagers? For ales floating beads is great since they are at the top, but what about bottom fermenting yeast strains? Would circulating via stir bar overcome this no matter the strain, or would you have to contain or sink the beads for lager?
If this works, I'm going back to my stir plate idea for primary fermentation since I won't have to fight the fallen yeast. Since I'm under positive pressure constantly, I wouldn't have the O2 going into the fermenting beer like in a starter to worry about and it would move the beer around the beads for greater yeast to beer contact. I'm in a Sanke so I plan on side wall stir bar agitation with a more spherical type of stir bar. My thoughts go to containing the beads in larger tea balls so they don't have any possibility of going into my dip tube when transferring to my serving keg.
One question that I am worrying about if this works: What about lagers? For ales floating beads is great since they are at the top, but what about bottom fermenting yeast strains? Would circulating via stir bar overcome this no matter the strain, or would you have to contain or sink the beads for lager?
Man this is a great experiment and I can't wait to see when tasting comes into the equation.
Just to clarify, though, a sphere only has the lowest surface area / volume ratio for a fixed quantity of substance. 10 grams of tiny spheres will have significantly more surface area than 10 grams rolled into a snake.
Soon as the goop hits the calcium solution, its surface tension pulls it into a sphere shape pretty much no matter how it started
I don't think the yeast are smart enough to know whether they're at the top or the bottom. Top fermenting yeast just naturally float up while they are actively fermenting, while bottom fermenting yeast naturally sink. Correct me if I'm wrong.
That's what I was thinking and hoping for. Now does anyone see a problem with containing them if a stir bar is agitating the active fermentation? Remember, I'm sealed up so no worry of O2 like goes on with a starter.
Certainly...I like the color idea. Assuming these things keep for reasonably long periods of time and reasonably high numbers of batches (and I consider that a very big assumption at this point), it'd be nice to see beads of all different colors sitting in your fridge.
Just to clarify, though, a sphere only has the lowest surface area / volume ratio for a fixed quantity of substance. 10 grams of tiny spheres will have significantly more surface area than 10 grams rolled into a snake.
You sound like a parent.actually budding off a little clone, on the other hand, leaves you scarred and closer to death.
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