Setting up a yeast lab?

[matt_m]

Anyone have recommendations on tutorials on setting up a yeast lab? Thinking that might be my winter project. I have the Malt/Hops/Yeast/Water series I really need to re-read but I've also become a big fan of watching YouTube videos for learning...problem is there's as many bad ones out there as good ones if you are just getting started on a topic.

 

[VikeMan]

What do you want to do with this lab? Count cells? Propagation and storage? Yeast banking? QA? Strain isolation and culturing?

 

[cyberbackpacker]

If you want videos, I highly recommend that you check out this channel on youtube:

Microscopy, yeast wrangling, etc.

 

[matt_m]

What do you want to do with this lab? Count cells? Propagation and storage? Yeast banking? QA? Strain isolation and culturing?

Probably mostly propagation and storage. Kind of assumed counting cells would be important there but don’t know what I don’t know.

 

[rtstrider]

What do you want to do with this lab? Count cells? Propagation and storage? Yeast banking? QA? Strain isolation and culturing?

I'd like to get into strain isolation. There's a local brewery in town that uses a proprietary house yeast. I'd like to clean it up and bank it. Any suggestions on where to start?

 

[matt_m]

Well I still haven't done this but its back on my mind again. I've had pretty regular access the last few years to a LHBS 4 hours away that where I could stock up on the yeasts I'd need for the next few months of brewing. Those days are drawing to a close over the next year and shipping will become a seasonal option. My main use case would be to keep a supply of yeasts I use regularly and propagate them to cover several months of brew days until I can restock and start over. I'm not sure that requires freezing yeast but assume I'd want to start doing counts and keeping an eye on any contamination.

 

[RM-MN]

You might want to read through this article before you spend a lot of time setting up your yeast lab. You may not need to,

http://www.woodlandbrew.com/2012/12/refrigeration-effects-on-yeast-viability.html

 

[user 246304]

Tons of free stuff everywhere - thanks actually guys, for some of the links. I'd add that I enjoyed the book when it came out, First Steps in Yeast Culture, Part One, by Pierre Rajotte. IIRC, at the back of Chris White's yeast book - doesn't he go through a pretty healthy section on setting up the home lab?

And for what it's worth, from a million lives ago when I actually knew a couple things and hadn't forgotten everything, just an assignment from Heriot-Watt (I was studying through their malting and brewing diploma program via distance learning, while working for Goose Island at the time).

 

[hottpeper13]

I took the Microbiology For Brewers course during spring break in 2016 at UW Stevens Point to learn all I could do with a small lab and to get the right equipment. After using my stuff to count,make agar plates and plate all my overbuild starters ( It was fun for a while and I got empirical data that gave me my SOP for pitching , repitching and how much overbuild to save) I haven't used it since 2017.
You need a bright field microscope with min. 400x magnification to count yeast and don't scrimp on the hemocetometer ( no china!). I got a pressure cooker for an autoclave to make agar and have some leftover in the jar that looks like the day it was made. All of my plated yeasts started to grow mold at the 8 month mark. Might have been me ,but I followed all the stuff I knew to keep everything sterile. I had enough 15 ml tubes of sterile wort to bring them back and have been doing overbuilds ever since.

What my empirical data showed me was that in a 1.050 - 5 gal batch 1/4 of the cake can be repitched on another batch, German ale yeasts I use 1/3 and lagers 1/2. This allows the yeast in subsequent batches to grow 3-5 fold ,which makes for the best viability.

 

[beren]

I really like the methods in Maintaining A Healthy Yeast Bank Long Term been working well I have about 150 vials now.

 

[beren]

I'd like to get into strain isolation. There's a local brewery in town that uses a proprietary house yeast. I'd like to clean it up and bank it. Any suggestions on where to start?

Is it in the bottle? You can just build up the dregs. I did this with allagash yeast. Yum.

 

[McMullan]

Probably mostly propagation and storage.

You don’t really need a lab to do that, to be honest. Do the smart thing by ‘contracting out’ the lab work (for free!) to White Labs, Wyeast, etc., and just buy your preferred strains then aliquot them straight from the packs into sterile 1.5ml cryovials or similar. Store them in a fridge. To propagate, add the contents of a 1.5ml vial to 50ml sterile wort. Step up when it’s done culturing. Repeat step up procedure until you have enough cells to pitch into FV wort. You don’t even need a microscope. Nice-to-haves include a pressure cooker, Bunsen burner, mechanical pipette with tips and 1.5ml tube racks. This is the most reliable and cost effective way for home brewers to store and culture yeast.

Edit: I didn’t see @hottpeper13’s post. Sound advice, but it soon becomes apparent you don’t really need one once you have a good idea what’s there, which can be determined empirically anyway. Which I think he or she alludes to. My P5000 pipette gets used considerably more than the dusty microscope sat in the corner. Pipette tips, for our purposes, are reusable too. Quite a useful tool for home brewers, in terms of precise small-volume liquid handling. A better investment, imho.

 

[hottpeper13]

^^^ so right. I nerded out after taking classes,spent money,learned a lot, and aren't hobbies posta cost money anyhow?

 

[bwible]

Here is one article on here:

https://www.homebrewtalk.com/threads/maintaining-a-healthy-yeast-bank-long-term.678997/
I tried freezing yeast with glycerine. My intent was to save off some special limited availability yeast that I couldn’t get or could only get it when the yeast company puts it out as a special seasonal yeast or a vault strain etc.

What I had was Wyeast 2035 American lager yeast which is one of their private collection strains I was hoping to be able to save and use a few times.

I bought the 50ml tubes, glycerine and all that. I wiped my work area with alcohol, put everything in Star San and tried to be as sanitary as possible without a hood or an autoclave.

It did not work out for me. I took one of the tubes out after only a month and made a starter and it was completely phenolic and contaminated, the starter smelled and tasted like a Belgian strain.

I still don’t know where I went off but I guess yeast ranchin is not for me.

 

[Bassman2003]

I agree, do not build a lab, just set yourself up to be able to store and grow yeast. I went to freezing because I want fresh cells, not old cells that you buy at the LHBS. Not much time savings as I pressure can starter wort and grow the yeast up from 50ml vials. But after some time, it does pay off and it is nice to grab a vial or two and get it going. A Pressure cooker is essential imho. You can make starter wort as well as wort + glycerin and store them on the shelf. I do this once every 12-18 months.

Shipping is becoming more a part of homebrewing and this just does not mix well with liquid yeast. So I see it as having two choices - move to dry yeast or build your bank of liquid yeast and only ship things every once and a while. Yeast is always dying. It is on the clock from the day it is propagated. So I would advise to set up your yeast process based around wanting better performance rather than convenience. Nothing is more convenient than buying and using.

I made a video of how I freeze yeast which is on my YT channel. Maybe it can help you to judge how easy it is.

 

[McMullan]

Freezing yeast cells successfully is going to be technically demanding for most home brewers, which is why I don’t recommend it. I do freeze yeast, but using lab protocols, which are very different from home brew protocols I’ve seen. I use the simple method I described above too for WLP007, which, for me, seems to lose its performance after being frozen. I find it much better just kept in small aliquots in the fridge, currently all good for >18 months so far. With prices going up so much, in my view, I’ll probably just prep a nice little sterile starter for realiquoting/storing when almost gone. It works really well with less effort than slants too.

 

[beren]

Here is one article on here:

https://www.homebrewtalk.com/threads/maintaining-a-healthy-yeast-bank-long-term.678997/
I tried freezing yeast with glycerine. My intent was to save off some special limited availability yeast that I couldn’t get or could only get it when the yeast company puts it out as a special seasonal yeast or a vault strain etc.

What I had was Wyeast 2035 American lager yeast which is one of their private collection strains I was hoping to be able to save and use a few times.

I bought the 50ml tubes, glycerine and all that. I wiped my work area with alcohol, put everything in Star San and tried to be as sanitary as possible without a hood or an autoclave.

It did not work out for me. I took one of the tubes out after only a month and made a starter and it was completely phenolic and contaminated, the starter smelled and tasted like a Belgian strain.

I still don’t know where I went off but I guess yeast ranchin is not for me.

Sounds like you need a little more practice. Did you use a pressure cooker to autoclave?

Might need its own thread, but what method did you use? I use 15ml not 50…

 

[user 246304]

-on pressure cookers, regret I sold off my 21.5 All-American when I sold off everything years ago. I do see Prestos and Mirros in larger sizes all the time, but suspect their quality. Is the suspicion unwarranted, for this purpose, home lab work?

 

[beren]

-on pressure cookers, regret I sold off my 21.5 All-American when I sold off everything years ago. I do see Prestos and Mirros in larger sizes all the time, but suspect their quality. Is the suspicion unwarranted, for this purpose, home lab work?

I use my electric breville and just up the time 5mins.

 

[user 246304]

I use my electric breville and just up the time 5mins.

There are a number of electric pressure cookers FB marketplace, but I guess I didn't realize they went as high as 15 psi. How much capacity do you have?

 

[beren]

There are a number of electric pressure cookers FB marketplace, but I guess I didn't realize they went as high as 15 psi. How much capacity do you have?

They do 12.5 with spikes in the 13s, good enough for me. That’s why I do a little longer time. Mine can hold 3 canning jars carefully but has no issue with my beakers and glass vials. Breville fast slow.

 

[user 246304]

They do 12.5 with spikes in the 13s, good enough for me. That’s why I do a little longer time. Mine can hold 3 canning jars carefully but has no issue with my beakers and glass vials. Breville fast slow.

Thanks.

 

[beren]

Thanks.

Well some instapots do 11.6 it looks like.

 

[Bassman2003]

I have a Presto old school cooker and I see no issue for these uses. I agree, freezing yeast is not optimal at the homebrew level, but I see it as a better alternative to buying half dead yeast if the LHBS only gets shipments in once or twice a month etc... to save money. I view it as long term repitching if you can keep the yeast alive.

Why would the yeast stay alive in the 1.5ml cryo vials at fridge temperatures any better than having an entire yeast cake after a batch in the fridge? Seems like without special treatment the cells would die. There is the isotonic approach which is at fridge temps. Which I think is in saline solution correct?

 

[beren]

I have a Presto old school cooker and I see no issue for these uses. I agree, freezing yeast is not optimal at the homebrew level, but I see it as a better alternative to buying half dead yeast if the LHBS only gets shipments in once or twice a month etc... to save money. I view it as long term repitching if you can keep the yeast alive.

Why would the yeast stay alive in the 1.5ml cryo vials at fridge temperatures any better than having an entire yeast cake after a batch in the fridge? Seems like without special treatment the cells would die. There is the isotonic approach which is at fridge temps. Which I think is in saline solution correct?

Read the link I posted, it’s from a microbiologist. Yeast do very well being frozen as long as the ice crystals don’t destroy the cells. That’s why you add glycerin and freeze them slowly.

 

[Bassman2003]

Sorry, I was speaking to McMullen saying to make 1.5ml vials from the purchased yeast and store them in the fridge. I already have a yeast freezing regimen in place.

 

[McMullan]

To be brutally honest, I wouldn’t employ that ‘microbiologist’ in my lab. Some glaring mistakes there, frankly. Freezing (and thawing) is so much more stressful on yeast cells (especially using glycerol, not just at a low conc and without incubation time to replace enough H2O molecules in and around membranes, cell and organelles ) that they really need QC on an agar plate with healthy-looking colonies being selected for propagation. Mutation is going to occur at a much higher rate when freezing compared with ‘cosy’ refrigeration temperature. The most vulnerable bits of DNA are the mitochondrial genomes (hello petit!) and the strands of DNA exposed on the surface of chromosomes. Then there’s the impact of freezing on the mRNA, the transcriptome and proteome, the ‘memory’ of the cells. I routinely QC yeast on plates when they come out of the freezer, after an overnight culture. I can say yeast kept in small aliquots in the fridge have noticeably fewer suspect-looking colonies on agar plates. Sure, much longer term, freezing is probably better, but I’m really not confined that time frame is relevant for most home brewers for something like yeast. There are clearly much simpler alternatives that are more reliable and more accessible to home brewers generally, imho.

As far as pressure cookers go, definitely use one if you have one, but don’t worry if you din’t. Double boil. ‘Simmer’ temp with lid on really. After the first boil, let it cook then leave it overnight. Any viable spores present ‘germinate’. Boil again to kill them. This is wort, it’s highly unlikely there’s going to be nasty thermophilic bugs in there. Focus on sterility when aliquoting and propagating 10-50ml cultures. After that, just follow good home brew practices. It’s not a problem to start treating it a little bit like food. It’s kind of what it is at this point, right? Best thing we can do really is pitch sufficient healthy yeast to get ethanol production going as soon as, to protect the wort from infection. That cooled kettle wort ain’t sterilised. It’s only been sanitised. Like most things at this stage, if we’re thorough.

 

[user 246304]

To be brutally honest, I wouldn’t employ that ‘microbiologist’ in my lab. Some glaring mistakes there, frankly. Freezing (and thawing) is so much more stressful on yeast cells (especially using glycerol, not just at a low conc and without incubation time to replace enough H2O molecules in and around membranes, cell and organelles ) that they really need QC on an agar plate with healthy-looking colonies being selected for propagation. Mutation is going to occur at a much higher rate when freezing compared with ‘cosy’ refrigeration temperature. The most vulnerable bits of DNA are the mitochondrial genomes (hello petit!) and the strands of DNA exposed on the surface of chromosomes. Then there’s the impact of freezing on the mRNA, the transcriptome and proteome, the ‘memory’ of the cells. I routinely QC yeast on plates when they come out of the freezer, after an overnight culture. I can say yeast kept in small aliquots in the fridge have noticeably fewer suspect-looking colonies on agar plates. Sure, much longer term, freezing is probably better, but I’m really not confined that time frame is relevant for most home brewers for something like yeast. There are clearly much simpler alternatives that are more reliable and more accessible to home brewers generally, imho.

As far as pressure cookers go, definitely use one if you have one, but don’t worry if you din’t. Double boil. ‘Simmer’ temp with lid on really. After the first boil, let it cook then leave it overnight. Any viable spores present ‘germinate’. Boil again to kill them. This is wort, it’s highly unlikely there’s going to be nasty thermophilic bugs in there. Focus on sterility when aliquoting and propagating 10-50ml cultures. After that, just follow good home brew practices. It’s not a problem to start treating it a little bit like food. It’s kind of what it is at this point, right? Best thing we can do really is pitch sufficient healthy yeast to get ethanol production going as soon as, to protect the wort from infection. That cooled kettle wort ain’t sterilised. It’s only been sanitised. Like most things at this stage, if we’re thorough.

Awesome. Thanks. Wasn't aware of that germination cycle on spores, so presumed it's 250 or face the consequences (potentially serious ones).

And on your aliquot-step process: You're saying take, e.g., an entire Wyeast pack and just keeping it in the fridge in a sterile 1.5ml Cryovial, then step into 50 ml., etc.?

Forgive the ignorance. Couple of questions:

-How is your aliquot process different from a basic stepped-starter from Wyeast etc. packs - i.e., a step or stepped starter, as per normal?

-Trying to see how this fits into a regimen of banking yeast, with the following purposes:

• I bank yeast to capture strains from bottles, etc. While on a brewery tour of England, a fortuitous trip my wife won on the web, I even captured some from Fuller's, Young's and Hook Norton (last one, hazy, but I believe so), and dried them on business cards; streaked, slanted them up at home.
• Bought slopes from Brewlabs, etc.
• Working with top-cropped yeasts that have been through an active full-fermentation, rather than stepped up via a pure Wyeast/WL/Imperial, etc., into stepped starter(s).
• A slope to return to after 3-5 generations, or so.

-can you address how what you're talking about, relates to these?

 

[Bassman2003]

@McMullan - I went to freezing because my attempts at keeping a yeast cake from a batch with the hopes of repitching at a later date proved unsuccessful. Basically, my brew schedule was too drawn out for the yeast to survive just under some wort in a mason jar at fridge temps. I have heard that two weeks is the cutoff for keeping a large amount of cells alive for repitching.

So can you add some more detail about your method? Does it only apply to yeast poured directly from the package as it is in a special solution for storage? So far I have a had good luck with all of my ale strains. Lager has been complicated as I also started pressure fermenting at normal lager temps which requires more yeast than normal. So I think my attempts from frozen have been underpitches. I am working on a solution of freezing bottles of 75ml of slurry from a batch and then starting with two and growing up for a batch.

While very little homebrewers do is "optimal", it can still be an improvement for schedules and not being a business etc... Thanks,

 

[beren]

To be brutally honest, I wouldn’t employ that ‘microbiologist’ in my lab. Some glaring mistakes there, frankly. Freezing (and thawing) is so much more stressful on yeast cells (especially using glycerol, not just at a low conc and without incubation time to replace enough H2O molecules in and around membranes, cell and organelles ) that they really need QC on an agar plate with healthy-looking colonies being selected for propagation. Mutation is going to occur at a much higher rate when freezing compared with ‘cosy’ refrigeration temperature. The most vulnerable bits of DNA are the mitochondrial genomes (hello petit!) and the strands of DNA exposed on the surface of chromosomes. Then there’s the impact of freezing on the mRNA, the transcriptome and proteome, the ‘memory’ of the cells. I routinely QC yeast on plates when they come out of the freezer, after an overnight culture. I can say yeast kept in small aliquots in the fridge have noticeably fewer suspect-looking colonies on agar plates. Sure, much longer term, freezing is probably better, but I’m really not confined that time frame is relevant for most home brewers for something like yeast. There are clearly much simpler alternatives that are more reliable and more accessible to home brewers generally, imho.

As far as pressure cookers go, definitely use one if you have one, but don’t worry if you din’t. Double boil. ‘Simmer’ temp with lid on really. After the first boil, let it cook then leave it overnight. Any viable spores present ‘germinate’. Boil again to kill them. This is wort, it’s highly unlikely there’s going to be nasty thermophilic bugs in there. Focus on sterility when aliquoting and propagating 10-50ml cultures. After that, just follow good home brew practices. It’s not a problem to start treating it a little bit like food. It’s kind of what it is at this point, right? Best thing we can do really is pitch sufficient healthy yeast to get ethanol production going as soon as, to protect the wort from infection. That cooled kettle wort ain’t sterilised. It’s only been sanitised. Like most things at this stage, if we’re thorough.

He does mention to leave in the fridge for a few days before freezing to increase vitality but doesn’t say exactly why…