Maintaining a house yeast

Hi everybody

I am doing a lot of small batches of about 5 liters and to avoid buying a vial of yeast every time i would like to try and maintain a house yeast.

My thought is to make a small starter each time and simply take a portion of the fully fermented starter slurry to save for the next brew, much like maintaining a sourdough.

I read that the strains can drift, but how long can i keep on doing a procedure like this. Do you guys have any experiences?

BR Jesper

if you are very clean you can go on for a long time. just be aware that you run the danger of propagating on any wild yeast or bacteria you pick up on the way. as soon as things start getting weird, like super cloudy beer, extra dry watery beer, dusty/overattenuative yeast, bad/low attenuation, any off flavors, bag that yeast and start fresh.
i assume you mean taking slurry from the previous batch, as for consecutive 5L batches you won't be making a starter each time

dinnerstick said:

i assume you mean taking slurry from the previous batch, as for consecutive 5L batches you won't be making a starter each time

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Part of the reason for the starter, was so that i could take part of it to keep for the house yeast. That way i would not stress it with any high gravity beers that i´d might do.

Jesper. I am in the middle of starting up the same thing. I make a starter. Save half and make an additional starter with the other half. That goes in the beer. That way I always have first gen yeast to work with and I am not using the sludge at the bottom of a batch

That sounds awesome, but is it necessary with the second step?

I will try to go with just the single step. Let me know how it goes and I will do the same

just to clarify, i assume you're pitching a vial or smack pack into a 5L beer, then reusing some of the slurry for the next beer, and so on? if this is the case you don't ever need to make a starter, as the pack is more than enough (unless ancient) for 5L of even a high gravity beer, and subsequent pitches come directly from the slurry. ?

dinnerstick said:

just to clarify, i assume you're pitching a vial or smack pack into a 5L beer, then reusing some of the slurry for the next beer, and so on? if this is the case you don't ever need to make a starter, as the pack is more than enough (unless ancient) for 5L of even a high gravity beer, and subsequent pitches come directly from the slurry. ?

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The thing is that I want to brew quite a few 5 l batches of single hop ipa's using the same strain, but probably only one or two at a time. By making a small starter every time and save slurry from that I suspect I could keep the yeast cleaner and fresher. I'm scaling to 5 l by trying to calculate a proper pitching rate for the gravity and volume of the wort.

JesperP said:

By making a small starter every time and save slurry from that I suspect I could keep the yeast cleaner and fresher.

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That is correct, however, keep in mind that some strains will start to mutate after 6 - 8 generations and will start to produce off flavors.

With your first fresh, unused starter, make it double the normal size, decant and pour into 1/2 pint jars (usually 4) leaving enough to make your beer for the day. With those 4, you can make 4 more from each then 4 more from those and so on... Until you get to the 6 - 8th generation.. I think it comes out to about 4096 uses on the 6th gen.

1st gen - 4 1/2 pint jars
2nd gen - 16
3rd gen - 64
4th gen - 256
5th gen - 1024
6th gen - 4096

I use Platinum strains from White Labs (limited releases) so I make them last at least a year by doing this..

I just came across this thread. I've been maintaining a starter in a 5 gal carboy of a Lager yeast. I make 24 gal batches and use a 1/2 gal of the starter (with the liquid) for each 5 gal batch. I'm am now on the 6th or 7th use of this strain. I keep about a 1/2 gal in the carboy after pitching in the beer. I then make a 2 1/2 gal starter of wort using liquid LME of about a 1.030 gravity two days before brewing. Seems to work well for me so far. I've kept this strain in the same carboy and have been brewing about once a week. If I miss a brew week I've added about a gal starter so the yeast does not go too long not being fed. I keep the starter in the shop at around 52 deg, except when I get it going again it comes into the house around 65 deg. Going to make a starter again today as I will be brewing again on Sunday. Fed it last Sat with a gal as it had been a week since I brewed with it last. Will post again how long this method works for me. I'm tempted to buy a scope and starting viewing the yeast to see first hand when it might start changing instead of guessing by how it looks during and after fermtent and how the beer tastes. Kegged an Alt last night that was brewed on 12/14/ the last generation used. Went from 1.048 to 1.014 and the it was a nice steady ferment that finished in about 10 days.

Warrior said:

I make 24 gal batches and have been brewing about once a week

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Awesome, drink up!

BTW several of us brew the 24 gal batches. I'm a lush, but not that much of a lush

through trial and error i have developed my own opinions and techniques for saving and reusing yeast. I know that popular "opinion" is that reused yeast is no good after ~ 6 gen or so. I am not a microbiologist however I have used and reused lots of yeast and just have not experienced this. I dont believe that there is some automattic trigger in the yeast cells that says " come on girls, 6th gen, time to mutate!". also I dont believe there is the same trigger that says from gen 1-5 "dont mutate". from my understanding this is not how life works. yeast do what they do. metabolize and reproduce. wierd thigs occasionaly happen and can be caused by environmental factors and genes can get screwed up during reproduction in the sixth generation or the first. whether or not this gene continues to reproduce in its new f'ed up version or not can, but doesnt necessarily, change any characteristic of the yeast if it grows to big numbers in the culture. it is also not certain to change anything that you would notice.

my method is to reuse yeast for as long as it serves me.I save tons of it, I make proper starters and ferment at the right temp. if the yeast works, I save it for next time. if it doesnt I throw it out.

How bad are other bugs? I've been trying to get a clean starter culture going and I'm having a hard time. I've been using a scope and always have the odd bacteria hitching along. I've been trying to get streaking agar plates down to get a clean strain but there is always some form of bacteria. I have a hard time comprehending how infected some strains are after being repitched several times. Some bacteria must not put out the off flavours.

Just dumped that starter I made, started to have have a slight after taste. It was used in 9 batches. Went and bought 2 new vials and made another starter last night. Need to get a scope, only real way to monitor the yeast. Can probably safely do at least 6 batches as long as I keep feeding the yeast.