How long does yeast last?

[OtherWhiteMeat]

Ive been reserching doing yeast starters on this board. Ive come up with the fact that yeast starter multiplies your yeast to create quicker/better fermentation. Makes sence. My question is, how long can you keep this yeast alive once youve done a starter, and how do you do so? Basicly im asking if you can multiply yeast, split it, save half and use it for another batch? Asuming you use the same particular yeast a lot.

 

[Walker]

As long as the yeast is kept cold (but not frozen) it can live for several months and be used again.

I was reasearching this recently, because I am going to salvage yeast from the trub in my fermenters for use at a later time.

Take a look at this thread I started last week, with links to an articla about how to go about properly salvaging from your trub.

-walker

 

[OtherWhiteMeat]

Actually I read that post earlyer and i thik i even joined in the conversation. Im trying to find a way around using the trub becuase i dont want any extra ingrediants from the previous brew altering the new brew.

I do have a question about the trub though.. If i have a 1 inch thick layer of trub on the bottom of my primary, how much of that is yeast and how much is settling ingrediants? I use to think it was all the dme settling, or does the yeast multiply THAT MUCH?

 

[PT Ray]

I decided to brew several lager batches and decided on one strain of yeast to keep it simple. I made a starter in a 500ml flask using a Wyeast pack. After the fermentation started to slow down, I split the starter into several 125ml flasks. I kept airlocks on them until all activity stopped and the starter began to clear. I replaced the airlock with solid stoppers and placed in the refrigerator. Now I just take one of the 125ml flasks and build it upto a 1000ml starter and pitch.

 

[OtherWhiteMeat]

I decided to brew several lager batches and decided on one strain of yeast to keep it simple. I made a starter in a 500ml flask using a Wyeast pack. After the fermentation started to slow down, I split the starter into several 125ml flasks. I kept airlocks on them until all activity stopped and the starter began to clear. I replaced the airlock with solid stoppers and placed in the refrigerator. Now I just take one of the 125ml flaskds and build it upto a 1000ml starter and pitch.

Thats exacly what i was looking for!! Thanks. That yeast should be good for a long time right?? I mean packaged yeast has a shelf life of a few years. Note: I would never stretch it that long.

 

[Walker]

yes, it should last for several months if kept cold (which shuts the yeast down and stops it from turning cannibal.)

Sorry for the confusion about making a large starter and splitting it vs. salvaging from trub. The starter is probably a better way to go, but I only considered re-use AFTER pitching the smack-packs I had bought, so I didn't have this luxury.

I intend to do the large starter for future smack-packs, but am still going to try and salvage my 1056 (american ale) and 1084 (irish ale) from the trub of two of my fermenters and make starters with them ASAP.

I figure if I keep craming brewing stuff into the fridge (especially scuzzy looking bottles of gunk), I will finally be granted permission to buy a small dorm-fridge for the garage to keep my grains and yeasts in .

-walker

 

[OtherWhiteMeat]

yes, it should last for several months if kept cold (which shuts the yeast down and stops it from turning cannibal.)

Sorry for the confusion about making a large starter and splitting it vs. salvaging from trub. The starter is probably a better way to go, but I only considered re-use AFTER pitching the smack-packs I had bought, so I didn't have this luxury.

I intend to do the large starter for future smack-packs, but am still going to try and salvage my 1056 (american ale) and 1084 (irish ale) from the trub of two of my fermenters and make starters with them ASAP.

I figure if I keep craming brewing stuff into the fridge (especially scuzzy looking bottles of gunk), I will finally be granted permission to buy a small dorm-fridge for the garage to keep my grains and yeasts in .

-walker

I got permission for the fridge i just dont have the money.
Thanks for the input.

 

[80/-]

In the joy of home brewing Papazian suggests that yeast stored in the fridge should keep for a good number of months - he stresses that it is important be be ultra keen when it comes to keeping things sanitised - if possible aim closer to sterile and that the yeast, once stored, should be kept as still as possible.

He seems to think that jostling the yeast can increase the chnaces of autolysis.

HTH

80/-