Using yeast more than 5 times

[jceg316]

Breweries and homebrewers reuse yeast to save money, but it's said not to use the same yeast more than 5 times otherwise it mutates and flavours change.

I was wondering if this is bad for the beer? Would it be like pitching bad yeast or different yeast? Would I still get a good beer but with a different flavour profile?

 

[CreweBrewer]

I was wondering this. I'm also of the thinking that this is how brewhouse yeasts come about.

 

[TheRedDarren]

Breweries and homebrewers reuse yeast to save money, but it's said not to use the same yeast more than 5 times otherwise it mutates and flavours change.

I was wondering if this is bad for the beer? Would it be like pitching bad yeast or different yeast? Would I still get a good beer but with a different flavour profile?

They do mutate after time, but the beer would still be good providing the mutation isn't something to do with wild yeast or bacteria.
Common mutations are things like flocculation characteristics (hazy beer or yeast dropping out early) or attenuation characteristics (finished beer too sweet or too dry).

 

[GlentoranMark]

Is it mutations or is it just flavours from past brews spoiling? I reckon you could do the same yeast time and time again if your doing the exact same recipe.

How do commercial companies produce the same yeast over and over again?

 

[Covrich]

Yet to do this but I reckon you could get loads of batches by when you get your initial strain growing with a large starter and then splitting and so forth, once used and harvested grow again and split..

 

[MyQul]

Are you asking about the theory or practically how to do it to get more than 5 use out of yeast?

If your asking about the whys and wherefore's homebrewers mostly just bottom crop (scoop some sediment from the bottom) so doing this repeatedly put selective pressure on the yeast so you end up with results like theredarren has detailed.
Large breweries have dedicated labs for yeast propogation and smaller (micro) brewers simply uses dried yeast as it's a lot more economically sound to use it as it's much easier to handle. Also the yeast labs like white labs or wyeast will propogate a strain up to commercial pitching levels for you if a brewery wants

If your asking about how to go more than 5 generations I know three ways that you can go to at least 13 gens possibly infinitaley (or until you got bored with the strain)

1. Top cropping. This is just simply scooping the krausen and reusing it. Because you get lots of different types of cells you can top crop afaik indefinately. There are a couple of caveats. Not all strains are true top cropping strains so not worth bother doing it. I've read you have to get at the 'middle of the krausen too.
2. This technique is one I've come across recently and only read of it once, on another forum. 36 hours after pitching scoop a hole in the krausen and collect about 500ml of the the wort from just below the krausen in to a bottle. Let it ferment out then put the yeast you've got into a starter when you need it. I tried the first part of this and it worked well. Because your collecting just below the krausen you get all the different types of cells as the wort churns due to fermentation so I think you could possibly do this infinatley. Similar to top cropping but you dont need a big krausen
3. Overbuilding. Detailed here http://brulosophy.com/methods/yeast-harvesting/ He says he has gone to 13 gens so if you just repitched the trub from each gen 5 time then you could potentially get 13x5 uses out of 1 yeast packet/vial
3.

 

[mike77]

I bottom crop and store the yeast in jars in the fridge. I use part of the stored yeast to make a starter. I typically get several starters from one jar of yeast. If you collect two jars you'll get say 10 brews from one generation before needing to crop more.

 

[GlentoranMark]

I bottom crop and store the yeast in jars in the fridge. I use part of the stored yeast to make a starter. I typically get several starters from one jar of yeast. If you collect two jars you'll get say 10 brews from one generation before needing to crop more.

How long can you store a yeast this way?

 

[mike77]

I just used yeast last Sunday that I have had in the fridge since mid November. I've got another jar of that yeast to get through as well. Not sure what the max would be. Sure I read that half the live cell count dies in 6 months

 

[MyQul]

I just used yeast last Sunday that I have had in the fridge since mid November. I've got another jar of that yeast to get through as well. Not sure what the max would be. Sure I read that half the live cell count dies in 6 months

Do you just pitch it or make a starter?

 

[mickthetrick]

top cropping is a great way to harvest healthy yeast from what ive read and done over the last year or so. im using a yeast now that i know is at least 5 times cropped. we were lucky enough to get a test tube from the owner of the cullercoats brewery and have used and cropped from there. he top crops his yeast too. ive no idea what strain of yeast it is but its being tried in bitters, stouts, ipa and the results have being spot on. i always make a starter with it and go from there

 

[mike77]

Do you just pitch it or make a starter?

Usually I make a starter as I only need to use small amounts of the harvested yeast to make one. Hence I get several starters from one jar. I do sometimes just pitch from the jar. Most likely if I forgot to build a starter and happened to have fairly freshly collected yeast around.

 

[jceg316]

Thanks for the replies, this has been helpful. I've been brewing over 2 years now and have never reused yeast as I've not had the ability to (long story). Now my homebrewing has moved into my own home I can reuse yeast. I can really see the potential of this: I can reuse yeast from fermentation, but also from previous batches. So if I need some English ale yeast I can open that red ale I made 6 months ago with SO4 and harvest the yeast at the bottom, whilst also drinking a tasty beverage! I can finally harvest Orval yeast as well. On that note, Orval uses the same yeast as Westmalle and I believe Rochefort, but are the latter 2 bottle conditioned? Orval, whilst a very good beer, is my least favourite of the trappists.

This might might be off topic, but I've bought some off dried wine yeast from my homebrew shop. I'm gonna use it in something quite experimental. Would be good to have a "different" yeast on hand as well.

 

[Twostage]

How long can you store a yeast this way?

In one of the Papers from the Institute of federated breweries, link in the library, (which I can't find just now) which dated back to the turn of the 20th century they talk about using yeast which had been kept in a 10% sugar solution for 40 years. They made a starter and then brewed a barrel of beer from it.

I'll see if I can find it later.

 

[trueblue]

I get yeast from a local brewery. The head brewer has told me they top crop the yeast and reuse without ant rinsing or washing and have so since 1976.

 

[Tony1951]

we were lucky enough to get a test tube from the owner of the cullercoats brewery and have used and cropped from there. he top crops his yeast too. ive no idea what strain of yeast it is but its being tried in bitters, stouts, ipa and the results have being spot on.

Thanks for this Mick. I'm going to try and contact him and go down there if possible and offer to help as a dogs body in the brewing if he'll have me. Just looked at his website. It's an easy trip from here down to Cullercoats. :)

 

[mickthetrick]

Thanks for this Mick. I'm going to try and contact him and go down there if possible and offer to help as a dogs body in the brewing if he'll have me. Just looked at his website. It's an easy trip from here down to Cullercoats. :)

he brews some real nice beers. started out as a home brewer too i believe.

 

[Tony1951]

he brews some real nice beers. started out as a home brewer too i believe.

He might be more favourably disposed towards having an amateur about the place then, unless he has been invaded by hordes of opinionated home brewers before... I'll give it a try maybe and see if he wants someone to help out moving stuff and cleaning up. It would be really good to work through a whole brew process with them. They brew on a Friday I think, from what he says on his website. I go down to Cullercoats Whitley Bay area a few times a week anyway so it is no trouble if he wants a dog's body to do jobs.

EDIT:

I've been reading his website and they don't brew in Cullercoats, but in Wallsend so it is even easier to get to. He probably won't want amateur helpers in his way though....

 

[mickthetrick]

he did a talk at a meet the brewer night that was on in Fitzgeralds in Sunderland. was over a year ago now. thats were we got the yeast off him. seemed a descant sort and if thats what you want to do there's no harm in approaching him.

 

[Twostage]

In one of the Papers from the Institute of federated breweries, link in the library, (which I can't find just now) which dated back to the turn of the 20th century they talk about using yeast which had been kept in a 10% sugar solution for 40 years. They made a starter and then brewed a barrel of beer from it.

I'll see if I can find it later.

Can't find it. I did find this though...
http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1903.tb00201.x/epdf

Page 5 (and there is another example towards the end). Basically it says that after the third pitch the yeast will have lost its original character and will have adapted to whatever you are making.

I know the paper is over 100 years old but this was a real test by professional brewers.