Is it possible to "re-train" lazy yeast?

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elgrindio

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Ok, so I understand why this doesn't come up much, since most can just go out and buy more yeast if something happens. Unfortunately, I can't because I live in Ecuador, S.A., and the only yeast I have (if I don't want to use bread yeast!) is the Safale -05 that my family sent me in the mail. I've been re-using it pretty successfully time after time(I pretty much brew every week). The only problem is that sometimes my OG was a little low, so I included enough table sugar to increase it by about .08-.10. I did this several times in a row, since most of what I read online indicated that it couldn't hurt anything, and in fact, the beer turned out fine. The problem is that I think I have caused it to become "lazy". :eek: When I tested FG before bottling last time, it was around 1.020. This was after 2 weeks of fermentation, and it wasn't that big of a beer to start with. Around 1.050-55. Normal should be around 1.012-14. Is it possible to toughen up my yeast after what I've done?

Thanks everybody!
 
i don't know about retraining but i would save the yeast in various containers and build up a starter each time rather than repitching the whole thing at once. i'd bet the FG problem is not related to the sugar but i could be wrong.
 
You can do it by reversing the process, but it won't be easy or quick. Make a starter around 1.060 using only malt and put some of the yeast in it. Once it has fermented, repeat the process. Eventually, the yeast will lose its adaptation to the table sugar.
 
I really have to question if it's the sugar that did it. Just constantly reusing the yeast could produce the same effect.
 
Next time you get a fresh strain of yeast, try harvesting a sample for storage BEFORE you pitch. The yeast will only see malt and will be "trained" to ferment maltose rather than dextrose. That way what you do with the trub does not affect the next batch.
 
As someone else stated you can rebuild up the yeast culture by creating all malt starters. However, from my experience, when a yeast begins to mutate it is always better to just start over. I try not to go more than 5-6 generations on my saved yeast. I buy yeast once a year, and what I do is take all the trub from the bottom of the first ferment and "wash" it. I put it into 2-3 sanitized bottles and cap them and place them back in the fridge. I do this every time, and I have plenty of healty yeast to use all the time, By placing it in multiple containers that are labled, I know what yeasts have been highly used, and what yeasts should be discarded to prevent mutations.

If you truly have no way of getting any yeast shipped to you, you should definitely build up a starter with all malt, and do this several times, and you may be able to get it back to health.
 
Also to help prevent the problem in the future, provided it is not mutation but adaptation to the sugar, add the sugar at the end of fermentation when the yeast aren't reproducing. That way they'll keep the maltose fermenting genes.
 
He isn't really using that much sugar. What percent of the fermentables is the sugar? It's probably something unrelated to the sugar. Maybe mash temp or temperature or the yeast strain is old and maybe he has been unknowingly selecting for yeast that flocculate faster. I don't know how much I believe the whole saying that sucrose will train yeast and they will stop eating maltose. Maybe in extreme cases but they will be pretty hungry and there is plenty of maltose floating around.

I don't know if this would help but you could try to harvest yeast that don't floc as fast. Make a starter and wait for about half the yeast to crash out. Then make anther starter using the yeast that was in suspension and repeat this process a few times. Eventually I'd think you'd get a yeast that wouldn't floc as fast and would have higher attenuation. Has anybody tried this?
 
He isn't really using that much sugar. What percent of the fermentables is the sugar? It's probably something unrelated to the sugar. Maybe mash temp or temperature or the yeast strain is old and maybe he has been unknowingly selecting for yeast that flocculate faster. I don't know how much I believe the whole saying that sucrose will train yeast and they will stop eating maltose. Maybe in extreme cases but they will be pretty hungry and there is plenty of maltose floating around.

This si what I was getting at. Why is everybody so hung up on blaming the sugar? There's not that much sugar on there. The problems the OP is having could very well be due to repeated repitching and have nothing at all to do with sugar.
 
I really doubt the table sugar is your problem. When you mash grains (or use extract, for that matter), a significant portion of the starches are broken down to glucose, which is an even simplier sugar than sucrose (but sucrose is made up of glucose). Maltose is broken down by the yeast into glucose. It's not like you fed them something they don't regularly consume. Plus, many people add sugar additions in the fermentor and do not have problems with lazy yeast.
 

I know what they say....I know those people plus I have my own experience to draw from. And you certainly can reuse yeast. But at some point, you will start to lose viability and therefore performance. It sounds like the OP has gone through many repitches without doing anything to reculture and strengthen the yeast. That's the problem.
 
And while that little sugar may not harm the yeast initially, they will favor glucose over maltose and the offspring that do this more quickly will get a larger portion of resources and therefore a larger growth in numbers. Add the sugar later in fermentation will help but getting fresh unmutated test from time to time would be best. Or you could get into culturing.
 
Denny said:
I know what they say....I know those people plus I have my own experience to draw from. And you certainly can reuse yeast. But at some point, you will start to lose viability and therefore performance. It sounds like the OP has gone through many repitches without doing anything to reculture and strengthen the yeast. That's the problem.

Ok so if you are stranded on an island and have to continuously reuse yeast, how do you strenghten them. I see this phrase but to me it just says "buy more yeast". What does white labs do that keeps their yeast cultures awesome?
 
Erroneous said:
And while that little sugar may not harm the yeast initially, they will favor glucose over maltose and the offspring that do this more quickly will get a larger portion of resources and therefore a larger growth in numbers. Add the sugar later in fermentation will help but getting fresh unmutated test from time to time would be best. Or you could get into culturing.

I would assume yeast would evolve to get more efficient at using all the sugars in their solution if you keep using the same sugar mix like the guy above. I could see the yeast being slightly less reluctant to ferment a 100% maltose beer after being raised many cycles where sucrose is available however it wouldn't make any sense from an evolution perspective to select for yeast strains that couldn't ferment maltose well when 80+% of the sugar is malt. It would be like a cowboy being allergic to beef but its ok because the cornbread is more easy to digest. (this might be a horrible analogy)
 
Zinc deficiency can cause the problem of 'lazy' yeast. Iirc they need it for cell wall health and it's generally the only mineral a AG mash doesnt provide enough of.
 
Ok so if you are stranded on an island and have to continuously reuse yeast, how do you strenghten them. I see this phrase but to me it just says "buy more yeast". What does white labs do that keeps their yeast cultures awesome?

If you are stranded on a desert island, you use what you have! Fortunately, most of us don't have to worry about that. Wyeast and white have cultures cryogenically stored and reculture from them. They have labs to verify yeast performance. Most breweries reuse the yeast a certain number of times, then order fresh cultures. If the OP had that kind of facility he wouldn't be having the problems he is. But neither he, nor most of us, have that luxury. In that case, reusing the yeast a certain number of times and then starting over is about the only choice we have.
 
Denny said:
If you are stranded on a desert island, you use what you have! Fortunately, most of us don't have to worry about that. Wyeast and white have cultures cryogenically stored and reculture from them. They have labs to verify yeast performance. Most breweries reuse the yeast a certain number of times, then order fresh cultures. If the OP had that kind of facility he wouldn't be having the problems he is. But neither he, nor most of us, have that luxury. In that case, reusing the yeast a certain number of times and then starting over is about the only choice we have.

I'm not quite on an island but the poster is from Ecuador and he probably can't get new yeast easily.
 
I'm not quite on an island but the poster is from Ecuador and he probably can't get new yeast easily.

Yep, I understand. And he's also found that continually repitching doesn't work either. He needs a way top bank part of his yeast supply. Maybe making a starter for every batch, but keeping part of that starter to use in the future.
 
Denny said:
Yep, I understand. And he's also found that continually repitching doesn't work either. He needs a way top bank part of his yeast supply. Maybe making a starter for every batch, but keeping part of that starter to use in the future.

Yeah I think that would be good to do in the future. Is there anything you think that he can do about his current yeast strain?
 
Yeah I think that would be good to do in the future. Is there anything you think that he can do about his current yeast strain?

Maybe, as others have said, take a small portion of it and start building it up again. Truthfully, I think the best thing to do would be to somehow get more yeast and start over using a better procedure for saving yeast.
 
Then there's always wild fermentation...perhaps he could build up cultures from well kept bottles or find a brewery that does something besides lagers. Also he could look into making slants of one fresh batch of us-05. Did he mention how he reuses the yeast? Yeast cake, washing, etc?

For now though I'd make a starter and pitch the krausen into the batch.
 
Ok, great comments guys. Thanks. I wanted to clarify how I usually reuse the yeast:

Normally I just collect what's on the bottom of my carboy into a 1 or 2 liter plastic Coke bottle (sanitized of course!) This is usually done on bottling day, which is usually about 1 or 2 days before brewing day. What I collect usually starts to get active again in the Coke bottle, so much so that I have to release the pressure every few hours. I always thought that the main factor was to have "active" yeast. Since it seemed REALLY active to me, I almost never bothered to make a starter. I just dumped what I had collected from the carboy directly into the new wort a day or two later. Does anybody see any flaws in the process?

Also, I just collected yeast from the brand new SS conical that I made with a buddy. The beer has been there for 8 days and the sample I took was still at about 1.020, which tells me that the problem is probably happening again (or could it still come down from there??). Also, when I collected the yeast from the bottom spout, I expected to have it come out as a thick cake, like I;ve seen in videos, but instead it came out very runny and foamy and started to bubble up out of the Coke bottle I was using. Any theories?? thanks for the help guys! You're amazing!
 
I would also start adjusting your OG with your recipe and boil time, not by adding sucrose. I am not sure if it is correct but I have read that the dry strains might not be quite to the purity level as the liquids.....but that might just be Wyeast/White Labs marketing speak.
 
elgrindio said:
Ok, great comments guys. Thanks. I wanted to clarify how I usually reuse the yeast:

Normally I just collect what's on the bottom of my carboy into a 1 or 2 liter plastic Coke bottle (sanitized of course!) This is usually done on bottling day, which is usually about 1 or 2 days before brewing day. What I collect usually starts to get active again in the Coke bottle, so much so that I have to release the pressure every few hours. I always thought that the main factor was to have "active" yeast. Since it seemed REALLY active to me, I almost never bothered to make a starter. I just dumped what I had collected from the carboy directly into the new wort a day or two later. Does anybody see any flaws in the process?

Also, I just collected yeast from the brand new SS conical that I made with a buddy. The beer has been there for 8 days and the sample I took was still at about 1.020, which tells me that the problem is probably happening again (or could it still come down from there??). Also, when I collected the yeast from the bottom spout, I expected to have it come out as a thick cake, like I;ve seen in videos, but instead it came out very runny and foamy and started to bubble up out of the Coke bottle I was using. Any theories?? thanks for the help guys! You're amazing!

Are you chilling it? You want to let it get to fg, leave for two days then chill to 10degC to help yeast settle and compact a little, then retrieve yeast after a couple of days.
 
Are you chilling it? You want to let it get to fg, leave for two days then chill to 10degC to help yeast settle and compact a little, then retrieve yeast after a couple of days.

No, I never have chilled the beer when it was done. Never had a way to do it. I guess that would make a difference in how thick/heavy the yeast is coming out of there! Any explanation for why it keeps producing gas after I collect it? I have had to release the pressure regularly in my Coke bottle for the past 24 hours because of so much activity. Doesn't it seem that after 8 days the active, gas-producing fermentation would be over? Why does it keep producing CO2?

As far as buying here in the country, yes, I have since found someone that will sell me -04, -05, or a couple of others, so that will solve my problem. ( I think!) I guess I just want to know exactly what has been happening in my beer, so I can control things better in the future.
 
elgrindio said:
No, I never have chilled the beer when it was done. Never had a way to do it. I guess that would make a difference in how thick/heavy the yeast is coming out of there! Any explanation for why it keeps producing gas after I collect it? I have had to release the pressure regularly in my Coke bottle for the past 24 hours because of so much activity. Doesn't it seem that after 8 days the active, gas-producing fermentation would be over? Why does it keep producing CO2?

As far as buying here in the country, yes, I have since found someone that will sell me -04, -05, or a couple of others, so that will solve my problem. ( I think!) I guess I just want to know exactly what has been happening in my beer, so I can control things better in the future.

If it is still gassing up and the temperature has been constant (fluctuations can release co2 from suspension) then either the yeast hasn't finished yet or you have an infection. My money is first on temperature changes, then on infection. Either way if you could chill it down it'll help.
 
Try top-cropping perhaps. Reading up on that recommends skimming the dirt of first krausen off the top, then taking the middle layer of the krausen. I may start doing this myself. If harvesting from the bottom you need to essentially do the same thing: remove the top layer of yeast, harvest the middle, leave the trub behind.
 
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