Basic Stuff You'll Need For Yeast Culturing

If all you're looking to do is maintain a very small yeast bank with minimal effort, you may want to go with pre-poured agar tubes (slants) and plates (Petri dishes). If, however, you intend to do much more than that, the pre-poured option will get VERY expensive, very quickly, and you'll definitely want to make your own. Pre-poured media is available from Cynmar Scientific [link] at the following:

• Malt Extract Agar slants: Ask (I'm reasonably sure they'll do it). NOTE: Universal Beer Agar is NOT designed for culturing brewing yeast. It is designed for culturing beer spoilage organisms, etc.. It will sort of work, but only poorly at best. Stick with the MEA and you'll be ok.

• Links to cynmar are waiting for them to put their product index back online.
  Malt Extract Agar plates $ 10.25 (pack of 10)

We'll get back to this, with what I consider a much better solution, making your OWN slants and plates.

No matter which way you choose, you will definitely need the following items (or similar), at a minimum....

To begin with, you will need a pressure cooker set at 15 psi (121°C // 250°F). Here's the one I use: 8 qt Pressure Cooker from Pressure Cooker Outlet ($38.49). This is what I refer to as a "Poor Man's Autoclave" or "PMA" (normally I just refer to it as an autoclave, period, with the understanding that a real autoclave is a far more expensive monster—Here is an example of a 2 gallon (8 qt) autoclave from Cynmar. It "only" costs a "mere" $2,125.00 (it's a "value" model)...I'll stick with the pressure cooker!).

Remember, when working with yeast on slants and plates, and up to 10mL starters, this level, all work must be sterile; simply "sanitized" is NOT good enough. At this level, you're working with samples as small as a single cell—even a single cell of beer-spoilage bacteria or wild yeast represents a massive infection.

You will also need the following:

• For 10mL starter tubes
  • Vials for 10mL starters $7.75 (pack of 12) - prod. ID is 11527910.

  • GRADUATED SYRINGE, 10ml, PP, NON-STERILE, 10/PK - 10mL plastic (polypropylene—autoclavable) syringes for injecting wort into the starter tubes. $5.25 (pack of 10) - prod. ID is 15061011.

  • 600mL beakers for autoclaving vials $13.00 (pack of 6) - prod. ID is 11520144.

  • Test tube rack $4.25 - prod. ID 15025994.

  • 250mL Erlenmeyer Flasks $22.00 (case of 12) prod. ID is 11520157. Use these for pre-prepared, sterilized yeast starter wort. If you're making 10mL starter tubes, you are likely to have lots of wort left over from a normal 1L batch, so you might as well make up some sterile starter wort to have on-hand when you need it (keep in the fridge, and of course, always rotate, first-in-first-out). You're going to need this later, one way or another, so....

    You'll want to filter the wort with one of those cheap, re-usable coffee filters and a funnel (both sanitized, of course—at this point, sanitized is enough, as you are about to autoclave everything to sterilize it).

  • Number 6 solid (non-drilled) rubber stoppers (for 250mL Erlenmeyer flasks). $5.25 (1 lb bag) - prod. ID is 12433609.

  • 500mL Erlenmeyer Flasks $16.00 (case of 6) prod. ID is 11520159; and 1 pound bag of #7 drilled rubber stoppers $5.75 - prod. ID is 12433641.

  • 1000mL Erlenmeyer Flasks $31.00 (case of 6) prod. ID is 11520161; and 1 pound bag of #9 drilled rubber stoppers $5.75 - prod. ID is 12433645. (You may wish to use a #9.5 instead, as the #9 can be a bit small.)

  • Parafilm for sealing tubes and plates. $17.95 - prod. ID is 12031080. A little goes a long way (you stretch it around what you're sealing). For tubes, aluminum foil or plastic wrap (or if you really want to be careful, plastic wrap covered by aluminum foil) works just as well.

  • You will need some ultra-light DME, Wyeast Yeast Nutrient (available from good homebrew stores in their section on yeast culturing), and some pellet hops for your starter wort mix. You'll need this same wort when making Malt Extract Agar (MEA) for agar slants and plates, as well.

• For working with the yeast:
  • Nichrome inoculation loop $1.50 each - prod. ID is 13225101.

  • a good self-standing torch lighter (check your local cigar shop) or alcohol lamp—both of these burn at a high enough temperature to sterilize the inoculation loop.

Supplies for Making Agar Media

So, you're getting serious now, and finding the pre-poured media is too expensive, huh? Ok, let's move on to the next stage: making your own culture media. Here's what you'll need in terms of supplies:

• A pressure cooker, as listed above.

• You can make a good agar using agar-agar from your local Thai (or Asian in general) market. Agar-agar comes in both a powder and long, stringy form. Buy the powder (I got 2oz for $1.75) if it's available.

  You can also buy agar in more expensive forms (some only slightly more expensive) if you prefer.

• Starter wort made from DME and vials for master and working slants: $7.75 (per pack of 12) - prod. ID is 11527910. You will need two tubes (master/working slants) per yeast strain you wish to maintain. I suggest keeping extras on-hand as well (for any new strains you decide you want—remember to keep two per yeast strain).

• Clear glass vials W/autoclavable cap, 12mL 12/pk - These are perfect for making master slant tubes. Master slant tubes are typically smaller, and are only used for making new slants, whereas working slants are used as a source for starting up yeast.
• Clear glass vials W/autoclavable cap, 16mL 12/pk - These are good (not perfect...would prefer slightly narrower with a length of around 100mm–120mm rather than 70mm, but I'm having trouble finding it now that Cynmar has hosed their online site.
• Glass petri dish, 75X15mm,10/pk - Borosilicate glass, autoclavable. You may not need these—they are for isolating yeast from a potentially-contaminated sample.

Note: I do NOT work for Cynmar, even though, as you look at some of this, you might think I do. I have, however, been a very satisfied customer of theirs for about the last decade or so, and have yet to find another vendor to even meet, much less beat, their prices AND quality.

Also be advised that all links to Cynmar pages are subject to a screwy error on their site saying something along the lines of, "Sorry, your session has expired." Just reload the page using your browser's reload/refresh and the page should come up. Sorry...not something I have any control over.