How long will yeast starter last in fridge?

I intended on brewing today so therefore had a yeast starter prepared and is currently in the fridge (after spending about a day or so on a stir plate). It turns out I might not be able to brew for about another 4 or 5 days. Is there any harm in letting that starter sit in the fridge until then? Anything I would need to do to get it ready to pitch in 4-5 days?

THANKS!

Maybe the day before you plan on brewing, decant of the current yeast starters cake, and add some fresh wort, to get the yeast active and suspended again.

I had a similar scenario come up a few weeks ago. I made a starter (from harvested yeast) on a Thursday, intending to brew that Friday with Saturday or Sunday being the fall back plan. That never happened, so I put my starter in the fridge and wound up using it the following Friday.

Normally, I'll make a 2 liter starter and I'll pitch the whole thing. This time, since it was cold in the fridge I wound up decanting off most of the beer and left just enough to re-suspend the yeast. I don't think it matters one way or the other as long as everything you have done remains clean and sanitary.

Also, for the record, the history of this yeast gives credit to your yeast being just fine. This was an old vial of WLP001 from the late spring/early summer (I forget the date, I just knew it was "old"). I used it to make a 1.073 IPA that went down to 1.010. I harvested that on 9/11/09. I made a starter from one of the mason jars on 10/1/09. I didn't get to use it until 10/9/09 to make a 1.054 APA that went down to 1.010. I harvested THAT yeast last night. I tasted the beer that I moved to my secondary and was very happy with the results and it should be a really nice APA.

I know this is all overkill, but, hopefully it gives you the reassurance that your yeast will be fine.

Deuce said:

Maybe the day before you plan on brewing, decant of the current yeast starters cake, and add some fresh wort, to get the yeast active and suspended again.

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Am I considered at all that by adding fresh wort it is going to give me too much yeast? I don't want to overpitch......

I wouldn't worry too much. If you're worried about overpitching, you can probably go to MrMalty.com's calculator to see how much good yeast you need for your batch. 30ml is roughly an ounce. So if you don't have graduated marks on your starter vessel, you can estimate with a similar jar and some water just to see where your yeast level is at.

I think if you pitch as is (which I have and my recent batch turned out fine) you will be fine. If you step up the starter it most likely will be fine as well.

Let us know how everything turned out! Good luck.

janzik said:

Let us know how everything turned out! Good luck.

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No problems!! I decanted the beer, added another 500ML onto the yeast for a day and pitched....fermentation took off in about 8 hours!

Thanks for the help!