So you brought home a slant or a suspension with yeast on it. Now what?
First off, put it in the refrigerator. The rest will come later.
On your way to the fridge, take a peek at this thing. The clear glass container is a culture/test tube. The film around the cap may be parafilm (green in my case) or electrical tape. It serves to ensure the cap stays on and will also keep the lid/opening area cleaner.
The brown gelatinous stuff is the media, effectively solidified starter wort.
The chunks in the media are hot break, just like in your brewkettle. The media was made from DME an boiled (sterilized, actually) in a pressure cooker so you can think of each tube as a 5cc kettle. :-)
The creamy looking stuff on the surface of the media is the actual yeast. You can probably see the back-and-forth motion the instrument made when inoculating the media. Since yeast don't fly or move, when placed on a solid medium they grow outward from where they were deposited.
using your yeast culture
Ready to use this yeast? Let's get started. If you get lost in some of the jargon you you may want to review some terms.
Here are the steps required to get your culture from the test tube to the fermenter.
remove some yeast from the culture tube. Normally you will do this with a flamed "noc loop". Flame it until glowing, "quench" in sterile water. Dip into the culture and retrieve a bit (a "matchhead" size is fine).
If you intend to come back to this culture again and again be certain to cap it (and maybe flame the opening) ASAP. Normally lab workers keep the culture tube cap trapped in the pinkie finger of their noc loop hand for this purpose. Sounds weird, but easy to do once you've done it or seen it done. If you are not going back to the original culture for another dip then you can just set it down open.
stick it in a small amount of starter Sometimes you have to swish the loop around a bit to get it off the loop. Cultures can be sticky.
build up the starter until you have the appropriate volume. A stirplate will help cut down the generational times. You can do on a stirplate in 3.5-4 days what might otherwise take 7 days
you can go 10ml --> 100ml --> 1000ml, or whatever you like. I usually do 10ml --> 25ml --> 250 --> 500/1000ml, as I work with low/medium grav beers and it suits my current inventory of lab glassware.
some tips and overall precepts
Here are a few key ideas to keep in mind as you go:
working with cultures seems alien but it is as simple once you do it a time or two. Remember how weird and magical mashing seemed before you did it?
you will require more lead time than you need with just making a starter from a pitchable culture (ie, tube or smackpack). I usually start stepping up a culture about a week before I want to pitch.
Working with cultures requires careful sanitation, and for best results will involve actual sterilization (pressure cooker or autoclave).
although the initial starter sizes are tiny, the stepping-up process is exactly the same as you currently use for building up starters
contamination is very easy to spot in a pure culture; they are bursts of non-yeasty life. Blue, green, black, furry, ugly. Chunk it if this happens to you. No harm, no foul.
Culture tube - a small tube used to hold cultures. Usually have screw-on caps.
Test tubes are usually bigger and use rubber stoppers instead of lids.
Either way, borosilicate (aka pyrex) tubes with autoclavable closures are reusable.
flaming loop - heating the noc loop in a flame until it glows. Then the loop is quenched (cooled) in sterile water so you don't kill your yeasties when you touch them...
inoculation loop - aka "noc loop". A piece of lab gear with a thin steel wire (sometimes looped) at the end. The loop is sterilized between each step by flaming/quenching to prevent cross contamination between cultures. There should be no "double dipping" in the yeast ranching world. :-)
media - the stuff that yeast grows on or in. Slant and plate media is usually DME, nutrient, and a congealing agent (usually agar although gelatin can also be acceptable).
plate - a petri dish that holds a few milliliters of solid media. Used for streaking out cultures for isolation, verifying viability, etc. Generally not used for anything but growth and short-term storage.
slant - a container (generally a test or culture tube) that holds a few milliliters of solid media. The media is cooled with the tube at an angle so the media is slanted, thereby increasing the surface area.
streak - a thin line of pure culture gently dragged across the media, usually with an inoculating loop. The resulting yeast growth is only on the contacted area and makes a distinctive, cream-colored streak on the media.
suspension - a container (generally a test or culture tube) that holds a few milliliters of sterile, distilled water. Less common than slants, though suspensions are stable at room temps.
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