I have a selection of vials of yeast. I want to multiply the yeast so I can get more bang for my buck. But I don't want the potential side-effects one gets from using yeast cake from a batch. Any suggestions?

Build up a starter, split it in half, store one half in the fridge to save for next time.

Rebuild up other half in starter to pitching amount.

repeat with saved half next time.

Make a simple ale 5 gallons of a gravity around 1.040-5, then split the cake into jars, essentially you are making a big starter...

I do what Jeff suggested in a slightly modified way. I build my starter and poor off 50ml into a 50ml sterilized screw top tube, similar to what White labs packages their yeast in. Got them from a lab supply place online. Label and date the lid and into the fridge. I then use that saved portion for my next starter and go through the same routine. The 50ml samples are only ever used in starters and have never fermented a batch. As far as I'm concerned, as long as they never get infected, they will last forever. I keep about 10 varieties on hand and cycle through them as I need them. Only buy yeast when I'm interested in a particular strain to try for something new.

that's smart, robert. i might start doing that. you could even reuse the vial it came in. already labeled.

can those vials withstand boiling water? and the caps? maybe iodophor is wisest.

Sweetload Ya know, I thought about that, but they were so cheap, and I really wanted them completely sterile, so I decided to just bite the bullet and toss them after each use. They come gamma sterilized from the supplier. It really has worked well. I can't remember, but I thought they were listed as autoclave safe, but I did pressure cook a dozen or so with wort (to use when I am starting from a slant), and they really deformed pretty bad, so I was going to look for something else to use for that purpose. Boiling water probably, autoclave, doubtful.

But for what I am doing now they are absolutely perfect.

Here is what I use:

https://www.testtubesonline.com/ProductDetails.asp?ProductCode=422%2D0025W&CartID=0

25 pack for $7.65.. its a no brainer. That place has a lot of other cheap and very useful lab equipment, and they process and ship fast. cool place!!

Robert, is gamma sterilized kind a like hella sterilized?!?

Those look absolutely cool, especially since I was just talking with a couple of club members today about starting up a yeast bank so we could all share several strains. Thanks for the tip!

gamma = super hella


I like the yeast bank thing. I would love to get in on that if it really gets going and folks want to trade.

Robert - Could you give more detail on how you make up your vials? Do you wait until the starter is fully attenuated and draw off the majority of the liquid, or do you just mix everything together to pour into the vials? How thick is the fluid when put into the vials?

I would really just plan out your brews and go the yeast cake method. Just make sure that you are doing a good job of straining any hops or bagging any hops added after the boil. In the grand scheme of things, what are the additional risks compared to doing a series of starters and vials? If anything, all those extra steps seem like potential problem points to me.

I have planned my brews to allow reusing yeast cakes... I use baby food and white lab vials for my yeast storage.

I pour a yeast cake into 3-5 containers for future use. I usually don't reuse it again as it takes storage space.... None the less I'm happy with 1 yeast purchase for 4-5 brews...

Adam,

Starting from one of my 50ml tubes, there is usually only about 10ml of yeast cake at the bottom of the tube, so I start with a one pint starter. When its done I crash cool, decant most of the liquid and then move it to about 2L for Ales 4L for lagers. When thats complete I crash cool, and decant down to about 300ml. I usually let that warm up a bit so I can mix all of the yeast cake and spent wort really well, then I pour off 50ml into the new tube, label the lid with strain and date, and put it in a the fridge. Mixing well ensures that 50ml tube will end up with 10 to 15 ml of yeast cake in it when it settles out. Whats left from the whole process goes into my fermenter.

I've had tubes of yeast in my fridge for over a year and they start right up. And like I said, I try to cycle through them roughly based on their date to make sure they get a refresh at least once every 8 to 12 months.

Seems a little complicated, but it only takes 2 to 3 days and ensures I always have a nice clean yeast to start from at any time. I rarely buy yeast now that I have my "library" of yeast that I like to use on a regular basis. I will also use a slurry from a previous batch if it happens to fit my brew schedule but I don't plan my batches around using the slurry.

Thats my technique, works for me. Hope it helps.

Sounds like the ticket Robert. Thanks. I think I will build a stock up. One quick question- do you wait for all activity to cease or do you harvest at the height of fermentation to insure maximum viability of the yeast?

I wait for the yeast to complete, because at the end of the yeasts cycle they rebuild their reserves before they flock. You basically want them to finish and then go into "hibernation" as healthy as possible. Also you don't want them to explode you test tube while in storage.

Kewl. Thanks!

BTW, as someone who works with radiation everyday... Gamma radiation is basically X-radiation but from a natural source such as an isotope of some sort. To sterilize the test-tubes it would have to be of a pretty high wavelength and a fair amount of it in order to kill all living organisms potentially extant. No need to worry though, the tubes are not radioactive. If you are a meat eater you might be surprised to know that the FDA allows meat and eggs to be "rendered less hazardous" in this manner. Supposedly it has a minor effect on taste...

I think these would make great storage containers for yeast. Looks like the same thing that White Labs uses. Plenty of volume and you can seal the lid without fear of it exploding. Should be reusable, with chemical sanitation.

http://www.testtubesonline.com/Baby_Soda_Btls_Giant_Test_Tubes_p/207-0031w.htm

Radtek - what issues do you speak of in re-using yeast cakes?

Well, you have a bunch of dead yeast and tired yeast that have been working in a progressively hostile environment who settle out when they can't do any more. Who really knows without a microscope as to the exact health of these yeast? Especially as SG goes up. Chris White states that there is always bacteria present even though they might not effect the batch initially, but their effects can show up in later batches.

I just think there is a better, less risky and more elegant approach to stretching out one's yeast. I've never had any problems with fresh yeast but have experienced a few setbacks when dumping on top of the yeast-cake. I know many swear by it but even Chris W. warns of potential problems by this method. He is in the business to sell yeast but he is also a homebrewer and I respect his opinion.

I think I might alter Robert's method slightly by propagating the first vial in a pint, but dividing it between 5-6 large vials so I don't need a starter for each. Each of those is 38ml so I would still have over 300ml to make a batch. This is the same size as WLP yeast vials.

I'm confused radtek. You say you are going to use larger vials than Robert, but 38 mL is smaller than 50 mL. Am I misinterpreting what you are saying?

Sorry, my bad. Coctyle, you are right. I thought those were the 16ml. I actually want something along the lines of 50-100ml. Thanks for alerting me to that.

Edit-

I found these too-

http://www.testtubesonline.com/50ml_Transport_Tube_Blue_Caps_p/421-0010w.htm

Rad- maybe it's just me being pragmatic but I haven't had any problems re-using a cake without a transfer. Then again I generally only do it once(two batches). Not more than that but this is just cause I move onto another style generally.

I will admit that I have begun to transfer to flasks as of late for longer storage of different strains. It is nice to have a bunch of different yeasts on hand. Helps cut down on the cost per batch.

Has anybody here ever made the effort to do any hard core yeast culturing? I'm talking about plate streaking, PDA slants, the whole works...

I've done it a few times, but N8 is the expert on this.

I do it as well.. I have a few things on slant now and have about 10 fresh slants waiting to get inoculated, haven't gotten around to it.

I'm currently culturing-up from a bottle of Boulevard Irish Ale - pretty unscientific, but cool if it actually works (it's my first try).

I did it for a few years, but once N8 joined our club it wasn't worth it anymore. Let N8 do it....

In terms of a hard core reference for yeast culturing is there a book out there that would help me do it right?

I've seen a lot on the web but most of it was personal experiences and there is a lot of variation in practices. I'm using what information I found to do some basic harvesting but I'd really like to know more. Short of going back to college and taking more biology classes what's best?

This http://maltosefalcons.com/tech/MB_Raines_Guide_to_Yeast_Culturing.php is some of the best info you'll ever find.

I think N8 is a yeastie streaking people on plates.... hic!

gotta love vendor sponsored dinner/after work beers....

OK I've come to a decision. Really wanting 100ml tubes I was about to order 50 50ml tubes from the site but the shipping was outrageous. I know these things aren't bulky or heavy. I got spooked and then remembered the 8oz canning jars at walmart. I can get twelve for about $11 and they have a vastly greater volume yet are still pretty small. The tubes appeal to my inner geek in a big way but my scrooge side prevails. I want a good pitchable volume without a need to make a starter. I figure 4oz of yeast will make for a good brisk ferment. A 3 pint starter should flll five jars and give me enough excess to make a batch too!

Radtek, don't you work in a hospital?

Yes I do and there is access to some vials with caps (maybe) but only about 16ml for lumbar punctures (spinal tap). Otherwise it's not something I really have access to without complex negotiations and explanations. Too much of a PITA but I'll look around anyway.

You could always stick some in your pocket. If nothing else, it'll impress the nurses.

maybe if you make a dwarf-sized beer, the 16ml vials wouldn't seem so small by comparison.

I'll brew my beer one pint at a time...

Couldn't you buy a tube of liquid yeast and make a big starter. Then, separate that starter into let's say...6-8 individual tubes of that particular yeast....before brewing anything. Now do that to maybe two more tubes of a different strain or whatever......end up with 24 seaprate tubes of 3 strains of yeast. So a starter could be made from each individual tube, per batch of beer. Then when it's time to brew again, grab another tube. So, each batch is limited to, (1)the original big starter for 6-8 tubes...(2)then the starter for the actual beer and (3)then the ferment of that beer........so a strain of yeast is used 3 times......
questions * is three uses too many before bacteria changes the flavor or things begin to mutate? * will the yeast survive long storage in an air tight container with only the starter wort and no special high speed purge with inert gas or whatever.......?

If I had 24 tubes of 3 different types of yeast in my fridge, that would last me all year because I would be hard pressed to brew 24 batches........but I would sure as hell try! I wouldn't mind spending $18 on 3 yeast strains at the beginging of each year.

then again, all these yeast harvesting horror stories could just be propaganda from the yeast manufacturers to scare us into buying fresh yeast each time!!!!!!!!!! =$$$

What you suggested would work fine. I just wished that I was disciplined enough to do that with each new batch of yeast.

P-man . . . in theory, that works, but why not just make one big starter called "a batch of beer"? A perk for your work, and you get to drink the benefits

As to your questions, I've used yeast up to six or seven times (on low gravity brews) with absolutely no ill effects. And be careful sealing up any yeast sample in anything airtight . . .

Went to two Walmarts. Evidently canning jars are 'seasonal' and there are only lids to be found. Then I had a realization. Screw jars and tubes. I have 12oz bottles. They can be capped. With a quarter full bottle I can then add wort to "freshen" up the yeast a couple days before I pitch. And I have a ready supply too...

I don't think you will want to cap the bottles
Yeast don't like to be in pressurized environs.
I would use something like plastic wrap or aluminum foil and a rubber band or twist tie.
Your not planning on turning them upside down or anything and then you could release the gas that is being
released by the yeast.

I've heard stories of exploding bottles from people who store yeast in capped bottles. Even refrigerated, the yeast will continue to slowly ferment wort in the bottles. Maybe if you used distilled water you'd be OK.

Capped bottle is a bad idea, I did it once years ago. It didn't explode, but it was one helluva volcano when I opened it. I think mason jars or some other type of lidded container you could burp occasionally would be a better route.

Doug

I have stored yeast in "canning jars" and they are excellent for it. I would just collect trub from a slurry of a previous primary ferment. Then I would get a couple of sterilized jars and water....and sort of rinse, whirl, and collect, but I haven't made a starter of fresh yeast exclusively for storage....I would store the jars in my fridge and I would also occasionally "burp" the jars. Now, I have read that when the yeast turns the color of peanut butter..trash it. Well, that doesn't take long, so how have people stored yeast for up to a year by doing the collection of slurries and without going through the more scientific process of plates and slants and agar?

hey radtek, try looking for some sterile screw top containers for urine samples. They should be around 50ml to 100ml, plus you can carry out 4 in your coat pocket with out any questions.

Yup, that didn't occur to me at first and I'm glad this has been brought up.

What's the difference between plastic vials and bottles? The WLP vials are stored sealed for long periods. Two things come to mind and possible solutions to them arise. The surface area of a 38ml vial is quite a bit smaller than the surface area of a bottle or even a jar. From physics I remember that as surface area of a container increases pressure begins to enact a greater force than one would think (particularly low pressure). So the same volumes of co2 in a 38ml vial vs a 12oz bottle can be quite safe for the smaller and become a grenade for the latter. In fact a higher pressure can be stored in the vial more safely.

Additionally, as I understand it we also have to think of partial pressure as it applies to this. I don't have this down pat but I'm thinking that as co2 is released into the available air gas space (gap) it applies an additional pressure effect to what the existing gases already apply (law of partial pressures). Think of a piston. So, the same above effect of surface also area applies. So, for the solution as Denny points out:

For instance- Take two 12oz glass bottles and put 30ml viable yeast in each. Top up one half way with the distilled water and the other with the same amount plus an additional 3-4oz distilled water. There is a dramatic difference in head space between the two and surface area. The half-full one would certainly be more likely to rupture if it continued to ferment. Think piston again. The bottle with more liquid would probably be able to tolerate much greater volumes of co2 overall and certainly in its headspace. At worst a gusher might occur though I think unlikely.

The second factor is strength. Plastic really is stronger than glass.

So, probably a better solution would be to use plastic soda-bottles instead of glass beer bottles if one wanted to play it really safe.

Which brings to mind... In my area there is available these little 8oz sodas in plastic bottles for kid's lunches. Not expensive, and would satisfy all of the safety requirements.

This isn't comprehensive or even completely accurate since I'm dredging this up from my high-school days. I'm not an expert, but it's just how I understand it. Still, I don't want to endanger myself, so plastic it is.

Use PET bottles. They won't explode.

I have used sport drink bottles with success, ya know the ones that have the pop up nipple type tops, you can burp em if need be..

pop up nipples.... gotta love those...

is it not good to reuse the white lab vials?

I would!