10 Day Old Yeast Starter

Do you see any issues with a ten day old yeast starter? I never hit “send” on my order that I thought was coming early last week. It’s here and the starter has been on the stir plate for 10 days. Smells fine.

Since its been on a stir plate for 10 days, I would cold crash it for at least 48 hours (or until you brew), decant it, let it warm to pitching temps, and pitch it. The starter has fermented out and the stir plate has added O2, making the starter (now beer) stale. I would be concerned that it could transfer over if pitched whole.

Edited for misspellings… :oops:

[quote=“Loopie Beer”]The starter has fermented out and the stir plate has added O2, making the starter (now beer) stale. I would be concerned that it could transfer over if pitched whole.

Edited for misspellings… :oops: [/quote]

I would not be concerned with yeast from a 10 day old starter. That is really not that old for yeast if you think about purchased yeast, travel time, etc and it is still considered fresh.

I do have a question about O2 in a starter and stale beer. Prior to fermentation you want to add O2 to your wort, then fermentation removes the O2 as part of the process. How would O2 in a starter not be anything but more O2 for your wort which would be removed once the main fermentation takes place?

There is nothing wrong with cold crashing and only pitching the yeast, its just that I have heard in lots of places about stale starters but at the same time you add O2 to wort. Seems like you can only have it one way, either O2 is good for wort and you are doing a good thing by adding aerated starters or O2 is bad.

The starter has finished fementing out after 10 days. This equals beer, not wort. Adding oxygen after fermentation takes place stales beer, especially after 10 days of constant aeration. I don’t think adding new yeast and wort will remove the oxidizing effects. This is why I would cold crash it and pitch just the slurry. You are more than welcome to pitch the whole thing, but I would prefer to be safe than sorry.

I’m sure you are fine, but next time I would cold crash your starter after 48 hrs. Neva Parker from White Labs has said that is the best method for maintaining yeast health. It helps the yeast cell wall health and helps them build up nutrient stores.

And there is no reason to warm up to pitching temps after cold crashing. That will happen as soon as you pour it in the wort

I’ve used yeast cake after a month with no problems. I agree with the advice to deacant what you can before pitching. But as for yeast viability it will be great.