Yeast Banking

[Haish]

Over the weekend I added 4 new strains to my yeast library. First of all, a big thanks to Reviled for donating the strains, I'll drop your frozen vials off tomorrow :) Strains were wyeast 1026, 1084, 1469 and 1728. I have the good fortune to have access to a lab at work so all the gear I need is at my fingertips. I am also pretty familiar with sterile techniques and have experience playing around with yeast in a laboratory setting. Messy lab bench, but its sterile...

Anyway, I picked up some yeasties of Reviled last Wednesday, and tried a few of his tasty beers too (awesome Pliny clone!!). Pitched four strains into 300 – 400 mL of 1.040 nutrient rich wort for starters on Friday, and grew them to stationary phase. All starters were grown in erlenmeyer flasks in a shaking incubator at 25oC for nearly two days. A shaking incubator is like a stir platebut without a stirbar and is the recommended method for growing cultures in a lab. 25 degrees is the optimal temperature for sexual reproduction of brewing yeast. Yeasties!!!

Innoculate

Ready to shake

Shake my pretties

On Sunday the cultures were well and truly fermented out. I centrifuged 150 mL of each culture to pellet the yeast and discarded the beer on top. I resuspended the pellets in the remainder of the cultures, the idea being to double the cell count. These ultra thick cultures were pipetted, 15 mL each into 50 mL Falcon tubes and placed into the cold room at 4oC for 24 hours. Incubating yeast at 4oC for 24 hours encourages them to produce the cell wall proteins they need to survive freezing and ensures more viable yeast when thawed. Stationary cultures, perfect!

Pellets

Dry pellets

A lot of yeast!

Today I added 15 mL sterile 30% glycerol to each tube for a final concentration of 15% and froze them at -20oC. I also made some 1.5 mL glycerols and froze them at -80oC for longer term storage. 15% glycerol is the recommended concentration of cryoprotectant for optimal survival. So that’s it, four new strains added. In stock are 1026, 1056, 1084, 1318, 1469, 1728, 2000 and 3068. I have a couple more strains ready for culture, wyeast 1272 and 2124. If anyone wants to add to the library (and get some frozen vials in return), or wants to swap some yeast then let me know and I’ll try to work something out. I will also try to sort out some slants to make sending yeast around the place a bit easier because shipping frozen stuff is a pita.

[denimglen]

Swap? No. Donate? Yes. Trying to kinda keep the strains I hold on hand at a minimum for a moment so not really looking to take on any more for now, but I'm happy to give you a vial each of what I have.

I'll have a look a little later and let you know what I've got, some have been in there a while so viability may be a little low, but sounds like you can deal with that, I try and keep everything as sterile as possible but can't guarantee anything.

It's a good thing you're starting mate, I reckon you should start selling slants, that would be mean as.

[Haish]

Nice one. I'll be in touch when I'm ready to make the next deposit to the bank. I think I'm going to do some test batches with the yeasts to check they're sweet, the starters certainly smelt fine.

I'm looking in to slants because they're easier to send around. I'm not really in it for the money so any payments would just be to cover costs...

[Mike Neilson]

With the slant's I take it they are agar slants, if so how does the likes of myself get it off the slant and into a starter?

[James P]

Just put some wort in the vial, shake the F out of it, then pour into your starter on the stirplate. Stepping from 50ml to 250ml to 2litres or whatever is required.

[James P]

Yeast co-op haish? Similar to BABB.... yeast bank

[Mike Neilson]

Get that but what? you just scrape the cells of the agar plate into the wort?

[James P]

Everything in the slant goes in the starter. The agar too. It normally has some sort of nutrient in the agar medium for growing the yeast colony.

[denimglen]

Hey mate, just went through the inventory, I can spare a vial each of -

WLP028 - Edinburgh Scottish Ale
WLP008 - East Coast Ale
WY1318 - London Ale III
WLP300 - Hefeweizen Ale
WY1214 - Belgian Ale
WLP029 - German Ale/Kolsch
WY1968 - London ESB Ale
WY1056 - American Ale
WLP810 - San Francisco Lager

Each vial is 10mL slurry, mixed with 3mL of 'sterile' glycerin, into the fridge for 48 hours, then frozen since.

Lemme know if you're keen.

[Barry]

Fuck. This dry yeast user is in awe.

[studio1]

I'm keen DG!