Yeast immobilization: magic beans of fermentation

[MalFet]

Thank You MalFet, for taking the time not only to test, but also posting every step and tasting results.

Please correct me if I miss read/understood your results.

This sounds like some, could utilize the yeast beads in creating stronger IPAs using less hops, thus saving money, sounds like a win win for people that enjoy IPAs and or, cleaner, less yeast flavored beers.

Cheers

I'd hesitate to put it in terms of a specific conversion at this point, but in this one experiment the yeast beads produced a less yeast-forward beer.

I don't know why exactly that lead to a more bitter beer at this point. It could be that the cleaner profile simply allowed the existing alphas to shine through better, but it could also be that the relative lack of yeast floc's caused less of the sticky alpha acids to fall out of suspension during fermentation.

 

[GRBC]

I'd hesitate to put it in terms of a specific conversion at this point, but in this one experiment the yeast beads produced a less yeast-forward beer.

I don't know why exactly that lead to a more bitter beer at this point. It could be that the cleaner profile simply allowed the existing alphas to shine through better, but it could also be that the relative lack of yeast floc's caused less of the sticky alpha acids to fall out of suspension during fermentation.

Another possibility is that the alpha acids are the same between the two beers, but the absence of flocculating yeast in the beads beer resulted in less hop polyphenols falling out of suspension and the increased in perceived bitterness is not alpha acid related. Perhaps a fining of a sample of the beads beer would provide a means of testing that hypothesis?

 

[bottlebomber]

Man, how did I miss out on this?? I need to check the current threads more often. You are a gentleman and a scholar, Malfet.

 

[Hermit]

Just for arguments sake, are you suggesting to immobilize the algae with the yeast in the alginate? Does wort constitute "growth medium?" That would be awesome if it worked but something tells me bioluminescent yeast beads can't be that simple!

It was a joke.

 

[TANSTAAFB]

It was a joke.

You never know! You needed my Dad's new invention. The next advancement in accurate text based communication, parenthetical sarcasm. If you aren't serious just put it in parentheses ... (I love BMC) (The Lakers will come back against the Spurs) (You should put bioluminescent algae in your yeast beads) ... may your sarcasm never be lost on your virtual audience again!

 

[BrewKnurd]

You never know! You needed my Dad's new invention. The next advancement in accurate text based communication, parenthetical sarcasm. If you aren't serious just put it in parentheses ... (I love BMC) (The Lakers will come back against the Spurs) (You should put bioluminescent algae in your yeast beads) ... may your sarcasm never be lost on your virtual audience again!

Ok, but what about if I actually need to use parentheses (for an example or clarification, perhaps) in a non-sarcastic manner? (Other than that, stellar idea.)

 

[matteroftaste]

Ok, but what about if I actually need to use parentheses (for an example or classification, perhaps) in a non-sarcastic manner? (Other than that, stellar idea.)

Teehee, lol.
Not to detract from this awesome thread! Carry on gentlemen, this might be the best current Hbt thread.

 

[BBL_Brewer]

I'm interested to see how many times the beads can be reused. Are you going to do another small batch with your current beads or are you just going to start over with fresh beads and try a full 5 gallon batch? How about contamination concerns with reusing? Perhaps wash the beads like you would yeast slurry inbetween batches?

 

[Hermit]

I'm interested to see how many times the beads can be reused. Are you going to do another small batch with your current beads or are you just going to start over with fresh beads and try a full 5 gallon batch? How about contamination concerns with reusing? Perhaps wash the beads like you would yeast slurry inbetween batches?

Do you mean wash in the proper sense of the word and use an acid bath or wash in the now common usage of elutriate?

 

[BBL_Brewer]

Do you mean wash in the proper sense of the word and use an acid bath or wash in the now common usage of elutriate?

I was thinking a bubble bath would be the most effective

Seriously though, acid wash like you would yeast slurry.

 

[slickfish]

How much do you think would be required for a five gallon batch?
Maybe two 11.5 gram packets worth of beads?

 

[brant740]

How much do you think would be required for a five gallon batch?
Maybe two 11.5 gram packets worth of beads?

The best way to calculate might be to make a 5 gallon starter then make all yeast into beads.

 

[MalFet]

I'm interested to see how many times the beads can be reused. Are you going to do another small batch with your current beads or are you just going to start over with fresh beads and try a full 5 gallon batch? How about contamination concerns with reusing? Perhaps wash the beads like you would yeast slurry inbetween batches?

Yep, I washed the beads first in water and then with some over-concentrated starsan. I'm swamped with work this week, but sometime next week I'll probably try getting another batch on the stirplate going to see if that makes a difference.

How much do you think would be required for a five gallon batch?
Maybe two 11.5 gram packets worth of beads?

At this point, there's no real convention for pitching rates with immobilized yeasts. I ran this experiment under the assumption that I wanted my pitching rate to be roughly the same as the expected final yeast count from the control batch. But, I have absolutely no reason to believe that's the best way to do it.

Depending on the beer and how you handle the yeast, 23 grams would be a bit less than I used here. Give it a shot and let us know how it turns out!

 

[Hermit]

About all you can do is compare fermentation times and see if you can hone in on it that way I guess. Though, if you aren't getting the ester production from the beads the more the merrier I guess.

 

[brant740]

Yep, I washed the beads first in water and then with some over-concentrated starsan.

Did the Starsan affect bead quality at all? If the beads allow sugars in wouldn't it allow Starsan in killing the yeast?

 

[MalFet]

Did the Starsan affect bead quality at all? If the beads allow sugars in wouldn't it allow Starsan in killing the yeast?

Yeast stand up to acid relatively well, which is the principle behind acid washing.

 

[brycelarson]

I don't know why exactly that lead to a more bitter beer at this point. It could be that the cleaner profile simply allowed the existing alphas to shine through better, but it could also be that the relative lack of yeast floc's caused less of the sticky alpha acids to fall out of suspension during fermentation.

I'm guessing it's the lack of flocculation. I did a split batch with BRY97 as one of the yeasts. It drops hard at the end of fermentation - and it stripped a lot of bitterness.

Isn't someone doing IBU testing here on the forum for $5? I'll pay for the testing if you'll send it samples of these beers.

edit:
https://www.homebrewtalk.com/f41/5-ibu-testing-405038/

 

[MalFet]

I'm guessing it's the lack of flocculation. I did a split batch with BRY97 as one of the yeasts. It drops hard at the end of fermentation - and it stripped a lot of bitterness.

Isn't someone doing IBU testing here on the forum for $5? I'll pay for the testing if you'll send it samples of these beers.

edit:
https://www.homebrewtalk.com/f41/5-ibu-testing-405038/

I really appreciate the offer. So many people have reached out to help with this experiment in various ways. It speaks volumes on the community here.

There are a number of interesting questions here, but I've decided to wait on any real testing until I've got the protocol rounded out a bit more. There are a few things that I plan to do differently on the next batch. For example, when I made the first batch of beads, I didn't rinse them particularly well before I pitched them into the wort. I wonder if this is related to the jail-break I had a few days into fermentation. The sugar water I've been fermenting with a second, well-rinsed batch, for example, didn't cloud up.

Once I'm a bit more settled on process, I do indeed intend to pursue things like cell counts, IBU tests, etc.

 

[Hermit]

Just how permeable are the beads. Could you make a drip system comparable to a drip coffee machine?

 

[MalFet]

Just how permeable are the beads. Could you make a drip system comparable to a drip coffee machine?

I'm not sure I follow. What would the drip system do?

 

[Hermit]

I'm not sure I follow. What would the drip system do?

Ferment beer?

If the wort can pass through a 'sheet' (say 6 inches thick just to put a number on it) of this stuff then you just let gravity pull it through and you have beer at the other end. Even if it takes 3 days to pass through you would probably have full fermentation at that point.

You could just keep pouring wort in until the yeast give up.

 

[MalFet]

Ferment beer?

If the wort can pass through a 'sheet' (say 6 inches thick just to put a number on it) of this stuff then you just let gravity pull it through and you have beer at the other end. Even if it takes 3 days to pass through you would probably have full fermentation at that point.

You could just keep pouring wort in until the yeast give up.

Oh, I understand what you mean. Alginate-immobilized yeast is sometimes used in a similar way for biofuel generation.

It might work, though I suspect not at 6". What sort of advantages do you see over, say, pumping the wort through a column of beads? I'd be a bit reluctant to have five gallons of wort just sitting around until it had its turn to pass through the membrane.

 

[Hermit]

Oh, I understand what you mean. Alginate-immobilized yeast is sometimes used in a similar way for biofuel generation.

It might work, though I suspect not at 6". What sort of advantages do you see over, say, pumping the wort through a column of beads? I'd be a bit reluctant to have five gallons of wort just sitting around until it had its turn to pass through the membrane.

Good point. Part of the question is just how permeable the material is though. Wort tends to be thick. I tried filtering cooled wort though a coffee filter and it wouldn't go through.

 

[MalFet]

Good point. Part of the question is just how permeable the material is though. Wort tends to be thick. I tried filtering cooled wort though a coffee filter and it wouldn't go through.

If it wouldn't go through a coffee filter, it definitely won't go through this in any reasonable time.

I suspect fermentation is not particularly limited by permeability/surface area, but the beads have the roughly consistency of dried silicon caulk.

 

[scottland]

First off, awesome experiment. Secondly, I can offer some theories that might help explain your results.

The stronger hop presence in the bead beer is most likely due to the exponentially smaller surface area of the beads in comparison to the free yeast. Hop oils stick to yeast cells, and floccing yeast take some hop aroma and flavor with them, (as well as isomerized alpha acids). Breweries have tested this. Two identical worts measuring the same IBUs going into the fermenter can have very different IBU ratings when fermented with different yeasts. Harder floccing yeasts tended to have lower IBUs.

The cleaner beer could be merely attributed to the higher cell count to start with. The bulk of ester production occurs during the reproduction phase. Esters are still produced during the majority of fermentation, but not to the degree they are during the lag phase. Since the bead beer can't (and didnt need to) reproduce, that might very well explain the 'cleaner' profile.

I'd be interested to see the exact same experiment done, only to see you introduce a third sample pitched with 35bil free floating cells. I'd venture it would taste similar to the bead beer in terms of esters, but still lack behind in terms of hop character.

Awesome work! I'm very intrigued!

 

[brycelarson]

I'd be interested to see the exact same experiment done, only to see you introduce a third sample pitched with 35bil free floating cells. I'd venture it would taste similar to the bead beer in terms of esters, but still lack behind in terms of hop character.

good call - that's a great idea.

 

[ras07]

Did the Starsan affect bead quality at all? If the beads allow sugars in wouldn't it allow Starsan in killing the yeast?

Yeast stand up to acid relatively well, which is the principle behind acid washing.

This confuses me ... are you implying that Star San is ineffective at killing (e.g., wild) yeast? That would be news to me ... but it would also explain a lot (I'm battling a wild yeast issue).

My (possibly flawed) understanding is that Star San kills through a combination of a surfactant (which weakens cell walls) and low pH. Perhaps the gel in the beads is impermeable to the surfactant?

Or is Star San not as effective against yeast as I've been lead to believe?

 

[Hermit]

Or is Star San not as effective against yeast as I've been lead to believe?

This. It is more an antibacterial from my understanding.

 

[Hermit]

database is slow. duplicate

 

[reverendj1]

My understanding is it is more antibacterial.

Yeah, if it killed yeast, it wouldn't be a no-rinse sanitizer. Think of how many times your beer comes in contact with Star San (assuming you are sanitizing correctly). The guy at my LHBS said it actually breaks down into yeast nutrient in the fermenter. I don't know if that's true or not, but I do know Star San does not kill yeast (at least to any appreciable amount, if it does).