Rinsed Yeast Has Grey Layer

[bamer101]

I rinsed some yeast about 4 months ago from a marzen hybrid ale I brewed. I plan on using it tomorrow to brew a hard cider, just for kicks. However, when perusing the yeast washing forums I stumbled onto the discussion of botulism and have spent the last three hours in freak out mode. I feel like I rinsed the yeast appropriately, but still have some concerns. All four of my mason jars have a nice layer of yeast that is covered by a very thing layer of grey matter. I've attached a photo of one of the mason jars. I'm probably paranoid, but I'd appreciate some feedback before I pitch this tomorrow. I'd prefer not to keel over a couple months from now. I'm not going to use a starter and am going to pitch all four jars into 5 gallons of pasteurized unfiltered apple juice. I have two 5 gallon carboys and a couple cornys lying around and feel like this would be a no-hassle brew to fill up the fridge! I'm also going to improve my chest freezer with some 2x4s and some insulation to add some bar taps! No more picnic taps!:rockin:

 

[ScottSingleton]

You pitch directly from the stored washed yeast?

I'm no bug expert; but I do know forming botulism produces gasses. One of the reasons we always check our home-canned fruits and veggies for a properly depressed lid prior to using. If it's pushed up or warped in any way it's a sign of some sort of growth within.

I do know that my yeast starts to get grey when it dies; and the darker the yeast the less viable it is.

that's why I always use a starter, even for a pint sized washed container. It's just good practice to get the right size colony and ensure viability.

 

[TarheelBrew13]

My guess is that's a layer of dead yeast on top and that this jar was harvested from a beer that had been sitting for some time of that it has been in the fridge for a while. Is that true?

It shouldn't be a problem to brew with this yeast. I really don't think it's infected, just old.

 

[ryan0914]

It shouldbe fine its probably just some left over trub that didnt get compleatly washed out. It's no problem a little trub is no big deal. Im not 100% sure but from what I understand botulism can survive in beer because the PH is to low im sure the alcohol doesnt help them either.

 

[bamer101]

Scott, I would make a starter to ensure viability, but I'm just throwing some apple juice into a carboy and pitching the old rinsed yeast for sh*ts and giggles. I just want validation that I won't kill myself when I drink this a few months from now. When I read up on rinsing yeast, many people recommended leaving the lid a little loose in case the yeast was still active, some even recommended using aluminum foil as a cover. I tightened the lids fully after a few days and don't see any sings of warping so I hope it's okay...

 

[bamer101]

My guess is that's a layer of dead yeast on top and that this jar was harvested from a beer that had been sitting for some time of that it has been in the fridge for a while. Is that true?

It shouldn't be a problem to brew with this yeast. I really don't think it's infected, just old.

Yes, I had this particular brew in primary for about a month, and the rinsed yeast has been in the fridge for about 4 months.

 

[william_shakes_beer]

The white layer is viable yeast cells, the gray is dead yeast cells that become food for the living. You can use it until it turns the color of peanut butter.

 

[bamer101]

Okay thanks for the input guys. I just pitched two of the mason jars into 5 gallons of 100% pasteurized apple juice with no preservatives, and about a pound of table sugar...we'll see where this experiment takes me.

 

[dragonbreath11]

The white layer is viable yeast cells, the gray is dead yeast cells that become food for the living. You can use it until it turns the color of peanut butter.

...also if it starts smelling like soy sauce, it's done.

 

[bamer101]

botulism doesn't have a noticeable scent though, does it?