yeast starter, can you put yeast back in vial?

okay ive searched but no luck.......

Been making yeast starters for as long as i can remeber, but lately its been getting harder and harder to find the yeast strains im looking for at my lhbs
once you build up your starter (i usually use a liquid yeast) can you fill the vial that you originally pitched from (sanatized of course) back up and pop it back into the fridge for next time, just making another started from it....

Search for "yeast washing" and "yeast slants".

People don't usually use the vials, but I suppose that would work.

Better to use a canning jar sanitized by boiling. https://www.homebrewtalk.com/f13/yeast-washing-illustrated-41768/ is a great thread to show you the general rules, but also it focuses on salvaging yeast from a yeast cake. I think you've got a good idea saving yeast from the starter since it won't have been exposed to hops or high gravities yet. All the same procedures should apply.

In my testing the vials are pressure cannable and therefore sterilizable. The labels fall off, and the thin ridge below the cap deforms a bit but the lid and tube still fit together correctly.

I've got several vials left over from previous brews and would also like to use them for saving yeast. Why wouldn't starsan be fine for sanitizing?

The big thing here is "sterilization" not sanitization. Whenever I keep yeast for washing, I put all of the containers into my pressure cooker and heat them for at least 20 minutes. This will kill all bacteria and spores that may cause an infection in your yeast. Starsan works fine at disinfecting the surfaces, but you want to make sure everything is as clean as possible.

We're all doing this to save some money. $6-10 a pop for liquid yeast is quite expensive, but if you don't take the neccessary steps to ensure good sanitization you may end up ruining an entire batch and any amount of money you saved via yeast washing will be washed away, no pun intended...

When I make a starter, I don't use the whole vial. I pour about 1/4 of the vial into my starter. I can then use the vial 3 more times before it runs out.

Jason

fratermus said:

In my testing the vials are pressure cannable and therefore sterilizable. The labels fall off, and the thin ridge below the cap deforms a bit but the lid and tube still fit together correctly.

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so boiling the used vial for 5-10 mins should be okay then, gonna give it a try... ill just pop a label on it....

jason.mundy said:

When I make a starter, I don't use the whole vial. I pour about 1/4 of the vial into my starter. I can then use the vial 3 more times before it runs out.

Jason

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That's a great idea. I'm going to try that with some 051 this week. Thanks for the tip.

LIVETOBREW said:

so boiling the used vial for 5-10 mins should be okay then, gonna give it a try... ill just pop a label on it....

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Two caveats:

1. boiling will sanitize but not sterilize (in case you were shooting for sterilization)
2. the bottom of the pot is hotter than the boiling water, so put some kind of false bottom in there.

I have given up on yeast washing and I now use the technique you are describing here. You can read up on my experiment and my results here

You can use a White Labs vial a lot more than 4 times too. If you do a 3 stage starter with a stir plate, you only need several drops, but it does take a while and you need a stir plate to get a good cell count.

Day 1, add some drops of liquid yeast into 10 ml starter wort(small container.. I use a little glass cup), 3/4" or 1" stir bar
Day 2, add to 500 ml starter wort, step up to larger container, switch to 1.75" or 2" stir bar
Day 3, add 500 ml starter wort
Day 4, crash cool
Day 5, decant and pitch

I have done this a handful of times with great success. I end up with what would have been around 2 full vials worth of yeast. I'm not 100% of the quantity, but it's enough that you'll need a blowoff tube in about 24 hours or else you'll blow out your airlock or lid.

I am not quite sure how long this can be repeated without eventually contaminating the master vial. I try to open it, pour some and close it as quickly as humanly possible.

alpo said:

I am not quite sure how long this can be repeated without eventually contaminating the master vial. I try to open it, pour some and close it as quickly as humanly possible.

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This is why its best to have a master culture and a working culture when working with yeast. The master is only ever used to inoculate more working cultures. The working culture is used to step up to starters. This minimizes the chances of contaminating your master culture. If a working culture is contaminated, no big deal. You simply use another working culture or inoculate a new working culture from the master culture.