WLP630 2 Vials One expired - One new

[hedgehogbrew]

I picked up a vial of WLP630 Berliner Wiess over the weekend from Northern Brewer. Once I was home I realized that the vial expired in may of 2011. They shipped me a new vial already to make up for selling the expired vial.

My question is if I should pitch both vials into the Berliner Wiess I am going to brew over the weekend. I was thinking that adding the older vial to the newer vial would make my batch more sour since the bugs would have a greater viability than the yeast in the blend.

Let me know what you think about this.

 

[Brewskii]

I have heard of people adding yeast to the brewkettle ( I think ) as a yeast nutrient. I read up on it first but you should chuck the old one in the boil.

 

[bdupree]

i think theres a good chance that the expired yeast is still plenty viable. Just make a starter and see if it takes off. I've brewed with plenty of expired yeast and never had a problem with any of them.

 

[shawnbou]

This is probably too late for the OP, but I'm reviving this thread to post a recent similar experience I had with this White Labs blend.

I bought a vial of WLP630 about a year ago (March 2011) with an expiration date of May 2011. I had planned to start adding sour brews to my repertoire ... but then life hit me and I didn't do much brewing at all for the remainder of 2011, let alone have time or money to get extra gear for sour brews. So the vial sat in the fridge for a long time.

Earlier this year, I finally decided to take the plunge and see if the WLP630 was still viable after being 10 months expired. This past Saturday, I made a small batch BW and the blend did exactly what I've read it's supposed to do. Total time before any visible fermentation activity was about 80 hours, which is typical as the blend is calibrated to let the lacto take hold before the sacc propagates. But now there is a very healthy krauesen from the sacc fermentation, with little white streaks that look to me like the start of a lacto pellicle. I'm a happy man.

Granted, I'm dealing with a small batch (1.5 gal) so less cells were needed. But this experience is enough to make me have faith in the power of microbes beyond their stamped shelf life.

 

[Revvy]

If you make a starter, then the age of a yeast isn't really an issue. When you make a starter, and grow it, you're replicating more yeast to make up for any loss. You're making new, fresh yeast.

Bobby M did a test on year old stored yeast here; https://www.homebrewtalk.com/f13/testing-limits-yeast-viability-126707/

And my LHBS cells outdated tubes and packs of yeast dirt cheap 2-3 dollars each and I usually grab a couple tubes of belgian or other interesting yeast when I am there and shove it in my fridge. and I have never had a problem with one of those tubes.

I usually make a starter but I once pitched a year old tube of Belgian High Gravity yeast directly into a 2.5 gallon batch of a Belgian Dark Strong, and after about 4 days it took off beautifully.
The purpose of a starter is to reproduce any viable cells in a batch of yeast....that;s how we can grow a starter form the dregs in a bottle of beer incrementally...and that beer may be months old.

Even if you have a few still living cells, you can grow them....That's how we can harvest a huge starter (incrementally) from the dregs in a bottle of some commercial beers. You take those few living cells and grow them into more.

 

[shawnbou]

If you make a starter, then the age of a yeast isn't really an issue. When you make a starter, and grow it, you're replicating more yeast to make up for any loss. You're making new, fresh yeast.

Understood, and I typically make a starter for any liquid yeast I typically use. But I've read elsewhere that starters are not recommended for blends that have lacto in them, because the starter can favor the saccharomyces and give them a chance to overpower the lactobacillus. For that reason, I opted not to use a starter (even a small one) for the BW batch in question.