Harvesting yeast in sterile urine sample containers? (no, really!)

Hi brewers & brewettes! So, I'm trying to add yeast washing/reusing/parenting to my brew craft repertoire. I'm a newbie, but like many I'm very fascinated by the little yeasties + they're quite expensive here in Norway (like, $8 for a pack of Nottingham, $10-15 for liquid), so in the long run I could save some money by reusing and growing these tiny wonders of nature. Also, it makes me feel kinda mad scientist-y

So I've been reading up on yeast washing etc., and managed to wash the yeast from my latest brew, so now I have a jar in my fridge with approx. 50 ml of yeast (about 5 mm tall cake). I'm planning to use this for my next brew, but I'd also like to keep at least a small amount for later brews in the immediate future (read: january/february), if possible.

And now the real question: I work at the local hospital, and thus I can get small amounts of various stuff for free, amongst those are containers and tubes normally used for urine samples. I got an idea: use these for yeast collecting somehow!

I have these containers:


These are sterile, wrapped in plastic, etc. 100 ml.
They also have a "Integrated Transfer Device" (the yellow tube sticking down into it), which is basically a needle connected to a tube (needle is covered and sterile until you use it), so I can use smaller sample tubes, similar to these:

These are "filled" with vacuum, so by punching it into the "Integrated Transfer Device", whatever is in the container will be sucked into the sample tube, and voila! I have a 9 ml tube full of (mostly) yeast and nothing else!

Here's an link to an official PDF, explaining the stuff much better than I can do, with pictures! (Just imagine yeast instead of urine)
http://www.gbo.com/documents/980005_Urine_rev08_0608_e_small.PDF
I'll be using that exact beaker with "integrated transfer device", and optionally also the tubes with conical base. (And yes, I have tubes with no additives! (There are also tubes with preservatives and stuff))

How does that sound? As far as I can tell, it should be great for storing smaller amounts of yeast which I can later use to build up a large starter. You know, first quickly fill the larger (still sterile) container with washed yeast from sanitized jar, then transfer into smaller sterile tubes. The end result should be a tube with no air, just the washed yeast, and no other microbes except what does or does not come together with the yeast.

This should work, right? Or? Am I wrong? Any reason why this shouldn't work? Can the vacuum be bad for the yeast? I've read a bit, but haven't found anything about using this approach. My home is not exactly a sterile laboratory (more like a bachelor cave), but with these tools and good santitation I think I should be OK, no? I'm not thinking of long term storage or anything, just to keep some amounts of yeast around for my immediate future brews. And it would be cool to be able to just pull a small tube out of the fridge and build up a nice starter with it, if that's viable.

Or any other things you can think of which I could use these "tools" for

Sorry for all the open questions, this post became a bit of a brainstorm and maybe I'm overcomplicating things - but I'd really appreciate any input on this very much! Thanks!!!

(And yeah, I know there are many views on whether to reuse yeast or not and all that, so please only respond if you're pro-yeast-reincarnation )

I work at a medical school and have acquired all manner of containers like you suggest. As long as it's new or been sterilized then it really is just a container.

In fact I take pre-measured amounts of sanitizer to brews with me in these.



And do you think whitelabs had their tubes specially made? A container is just a container...it's what we put in them that sets them apart. Not the container itself. A urine sample container is still just a jar.....

Well, it should cut down on theft. Also you can slip a 'culture' into the lab. That ought to confuse the hell out of them.

I like Hermit's suggestion. One heck of a yeast infection down there.

Revvy said:

I work at a medical school and have acquired all manner of containers like you suggest. As long as it's new or been sterilized then it really is just a container.

In fact I take pre-measured amounts of sanitizer to brews with me in these.

And do you think whitelabs had their tubes specially made? A container is just a container...it's what we put in them that sets them apart. Not the container itself. A urine sample container is still just a jar.....

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Yeah, I figured that, but as a newbie I'm just a bit over-worried I guess... :cross: Thanks, that settled some worries! I think my thoughts are valid then. Working in a hospital is great for getting sanitizer and sterile stuff

Hermit said:

Also you can slip a 'culture' into the lab. That ought to confuse the hell out of them.

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LOL, yeah! "Hmm, this is my pee - am I drinking too much homebrew?"

I know a doctor who actually sent a piece of fermented salmon ("rakfisk" - http://en.wikipedia.org/wiki/Rakfisk ) to the lab during a christmas party of some kind. The lab people totally freaked out since they (at first) thought it was an actual tissue sample from a human which looked nothing like anything they'd expect!

there are a problem i can see with this. many of the tubes contain preservatives of some sorts. if you could find some that don't contain them then go for it.

greyhoundbrewing said:

there are a problem i can see with this. many of the tubes contain preservatives of some sorts. if you could find some that don't contain them then go for it.

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None of the tubes I've come across have preservatives in them. And most of the ahem "samples" I've given have been into dry jars.....

I've been wonder if those "hats" that I've had to use had any somewhat more pleasant uses for them.

there are some that come with out. but the tubes that come with the urine cups are for urine cultures and sensitivities. there are others for urinalysis, which also contain a preservative. there are the ones pictured in revvy's that dont contain preservatives. the ones for blood mostly contain a preservative. there is a red top glass tube that is about 10mls that doesnt contain anything. i think this one would be fine. if you have access to medical supplies, there are plenty of other containers that would be wonderful for yeast storage. hmmm i wonder if the blood culture bottles would work? they are the ones that look like the airplane liquor bottles. i think the anerobic ones would work best bc the would put the yeast to sleep secondary to no oxygen.

mark

Thanks for answers! The urine tubes I've got have no additives, it's written explicitly on the label. (see the pdf I linked to in the original post.) I know most (or all) tubes for blood have various additives, so I'm avoiding those.

I mostly do paperwork, so I don't know much about the "technical" stuff, but luckily I work at the nephrology (kidney) department, so we're serious about our urine containers we have tubes both with and without preservatives. The specific tubes I'll use have nothing but a vacuum inside, so the yeast will be sucked right in without any oxygen, so that should put 'em to sleep I guess, as greyhoundbrewing says.

Well, I'll give it a shot (pun not intended) and see how it goes!

Revvy said:

And do you think whitelabs had their tubes specially made? A container is just a container...it's what we put in them that sets them apart. Not the container itself. A urine sample container is still just a jar.....

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The Whitelabs vials are actually blow mold pre-forms. They are the precursor to all sorts of containers such as two liter bottles, shampoo bottles, etc. Normally these pre-forms are heated until molten everywhere except for the threaded portion. They are then placed in a mold and inflated with a blast of air like a balloon so they take the shape of the mold.

This is a great idea! I work in the medical field too and I can't believe I never thought of it.

The only problem I can see is with pressure buildup in the containers if you don't fab up some sort of airlock or blowoff. Who knows how much more collected yeast might continue to produce co2.

EKennett said:

This is a great idea! I work in the medical field too and I can't believe I never thought of it.

The only problem I can see is with pressure buildup in the containers if you don't fab up some sort of airlock or blowoff. Who knows how much more collected yeast might continue to produce co2.

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Shouldn't be a problem if the yeast are through fermenting the medium and there is nothing new to ferment in the tubes. Then into the fridge to put them to sleep..... zzzzzzzzz.....