Harvested yeast smells rubbery

[Matthuds]

Hi all this is my first post so please bear with me.

I washed some yeast for the first time using the methods described on here/YouTube and seemed to get 4 jars that looked good to go. ( this was from a primary cake that I racked off about a month ago.)

However having just opened 2 of them to make up a starter I noticed quite a strong rubbery smell, autolysis? Anyway I ditched those and noticed the other 2 jars looked a little clearer. One smelt like beer and yeast so I am guessing that ones good. The 4th and final jar had a very slight hint of the same rubber sour smell.

I pitched jars 3 and 4 into a starter ready for the weekend but I'm not sure if it will be bad?

I guess my questions are...

1.is the rubbery smell from the jar of harvested yeast autolysis or more likely and infection? And if so how can I prevent this in the future?
2. Is this going to ruin my starter?
3. If I step up the starter and pull out the fresh yeast into another flask when the first starter gets going will this help?

Thanks

Matt

Oh and it's a British Ale yeast strain I got from a local brewery.

 

[jtratcliff]

Hmmm... your yeast might be off.

I had a batch of harvested yeast with a slight burnt rubber smell. I pitched it anyway. It fermented but that
burnt rubber taste carried through and never went away.

I drank all 5 gallons as punishment and a lesson to never do that again.

 

[AngryMonk]

I harvested 2 qt of WLP002 a couple weeks ago and made myself the same remark, smells like rubber...
I have reused the yeast with great success so I do not worry about that anymore...

 

[Matthuds]

UPDATE: my starter has kick off pretty well on the stir plate over night. Nice looking krausen starting to form.

I will wait and see how it smells tomorrow...

 

[JonM]

I had the same thing come up last summer. Following a recommendation saw on HBT, I made a starter with the smelly yeast and then, when it was done, I swirled it up and let it settle for 20 minutes. Then poured the liquid into another container and cold crashed it. The stuff that settled out was clean and smelled good, and I used it later.

My understanding is that the smelly stuff was autolyzed yeast. Swirling/settling lets the dead stuff sink to the bottom, allowing me to decant good, viable yeast.

 

[Matthuds]

UPDATE: as this is only my second all grain batch i ditched the yeast, (even though the starer looked ok). Maybe ill risk it in the future, thank for the advise.

 

[Jogurt]

I think you chose wisely, since this is only your second batch. You will have plenty of time in the future to experiment with yeast reusing.

Personally, I believe that yeast reusing is advisable only if significant cost savings are available.

To put things in perspective, where I live, we have no access to liquid yeast. If I want some, I have to order from Poland, or Britain and the general cost is usually something around 16 pints of beer (measured in other ingedients used). And even then I have no guarantee of viability. So if I order liquid yeast I want to make sure I use it best as I can.

If brewing general British ale, I would just in throw some ordinary dry yeast and cross fingers. There is plenty of space for grave errors in repitching and you want to have mastered everything else first.

 

[jfr1111]

Good call throwing away the yeast. The first rule of reusing yeast is that if you have the slightest doubt, don't pitch it.

 

[jtratcliff]

But keep in mind, yeast smells... different. And not necessarily pleasant.

My bad batch was with a distinctly *burnt* rubber smell... not just rubbery.

Harvested yeast shouldn't smell necessarily nasty but it can smell a bit like ass and still be OK. Depends on the yeast. If it looks OK (no mold, no oily film, etc.) and only smells weird, you should ask yourself "how weird is this smell?"

If it's vomitous stank, well then yeah, toss it. But if it's just mildly unpleasant, then that might be normal for that yeast.

So here's my very helpful advice: Don't keep yeast that is in doubt but don't toss unnecessarily How's that for definitive?

 

[Calder]

It's autolysis.

Wash the yeast to drop the dead yeast, and pour off (and keep) the milky liquid. You can straight pitch that if it is fresh enough and you have enough, or let the yeast drop and make a starter with it.