Hey all you yeast farmers…How many different strains do you have on plates or slants at home?
How much space does that take up?
It seems like this would be an interesting side of the hobby to get involved with…Not sure how much more space I can claim for brewing stuff with the GF though… :
I’ve only just started so I’ve only got five varieties. I keep three slants of each (probably going to back that down to two per). As far as space, each vial that holds the slant isn’t a whole lot bigger than a chapstick.
I just signed up to maintain the club’s yeast bank. That should give me many more strains. So far I have about 10-15. Some might be dead though.
It all takes only a few plastic containers in which I keep the slants and stabs. Biggest problem is remembering to renew them about every 6-12 month.
Kai
Kai,
Have you considered placing you slants under sterile mineral oil after you grow them up? They will keep longer this way.
That’s pretty cool of you Kai. So, when someone wants a certain strain, you will grow a small population for them and then give it to them to make a starter?
Maybe that’s something my club should start looking into…
In our club, our pres. was a microbiologist by trade and volunteered to keep the club yeast bank. He took over the few slants I had and added maybe 20-25 more. He eventually gave it up because almost no one used it! :o
I heard about the mineral oil, but I also head that it is a mess. I may trest it at some point.
The plan is for me to grow until ~3-4 oz of active culture. Then further propagation doesn’t have to be sterile anymore and it becomes easier to handle. We’ll see how this works. My thinking is that it will save brewers lots of money. Especially if it is a strain that they don’t use often.
Kai
Right now I have 8 strains on hand - there are few more I want, so I think I’ll end up keeping 11 total. I just keep them in 100 mL glass jars in the fridge, so they take up very little space. Every time I make a starter, I pour 100 mL of it into a jar, and it goes back in the fridge. So the yeast only see ~1.035 starter wort, which should keep mutation to a minimum. Not quite as good as banking the original culture in glycerol and only using each tube once, but a lot easier.
I got started in yeast farming as a bank for the club. As people get new yeast they try to get me a sample to culture and I make up starters for people who need them. We’re just a small group but we have been steadily adding strains.
Does anyone have any specific information on using mineral oil? Do you basically add sterile mineral oil to a slant to keep the oxygen off the cultures?
I keep my cultures on a combination of plates, slants, and stab cultures. I’d like to try glycol freezing some cultures at some point but haven’t had a chance yet…
The mineral oil overlay is very simple. Simply fill you slant tube with sterile mineral oil to above the media level. Store in the fridge.
It basically just keeps the culture from drying out, and the absence of oxygen slows the metabolic rate. I haven’t done this at the homebrew level, but have used this technique at work. I believe expiration was set at about a year, but it would be fine some time after that.
Messy? I haven’t encountered this. At most, you get a loop full of oil along with your yeast, but you just plate it all and watch it grow…and its fun to burn the oil off your loop.
It may be common sense, but just be sure you only stick the portion of your loop into the oil that you have flamed. I have seen a couple people stick the whole damn thing in there including part of the “handle.” Also, you should flame the opening once the cap is removed and again after you enter the slant, before capping again.
does that work for any size starter? would you get about the same amount from 100mls from a 2L starter and a 4L starter?
I also maintain the yeast bank for my club. I have 25 strains on slants and also in glycerol stocks in a -80C freezer. I am in the process of working out trades with other yeast ranchers to increase the selection (let me know if you are interested), and whenever a club member buys a strain that we don’t have I take a sample. I use 2ml screw cap tubes for my slants, so my 25 strains with 2 slants of each all fits in a little 6"x6" box in the fridge.
When someone in the club wants to use a strain they have a choice of just taking a slant (after I pull a little from it to innoculate a replacement slant) to grow up a starter on their own, or I will step it up to pitching volume for them and they will cover the cost of the DME. It hasn’t been too popular so far, but I just started offering the service to the club and I think that it will be used more in the near future.
I am just getting ready to culture/“farm” yeast. I have been looking into it for a while.
Does anyone here have any experience with the technique of using sterile distilled water in a slant tube for storage as opposed to agar. It seems relatively straight forward and easy. I will post the link to the site I read about it on but I have a wicked time loading the page so… patience necessary! Interesting site though.
Where do you get your tubes at?
You can get the tubes at Cynmar.com. I use the 12 ml autoclaveable vials.
The distilled water method sounds interesting. I also heard about using 0.9% NaCl solution for yeast storage.
Kai
I’m a Ph.D. student in microbiology, so I get them at work. I buy office supplies for the lab in exchange for tubes/glassware/etc.
The cell density in a 2 L starter and a 4 L starter probably won’t be the same, but from a practical perspective, I don’t really care if I’m collecting 20 billion cells or 30 billion - I’m going to be building it up again anyway.