Procudure for Starting Yeast from Slants
The following assumes you are right-handed. You may wish to reverse
things if you are left-handed.
- Turn off ALL sources of air movement, close any open
windows, etc., and while yeast is exposed, no breathing, either.
ABSOLUTELY NO AIR MOVEMENT CAN BE TOLERATED WHILE YEAST IS EXPOSED.
- Clean your work area completely and spray the entire area
with 73–75 percent (max kill) isopropyl alcohol (equal parts of
the weaker 50-something percent and the 92 percent available
from any pharmacy) or ethyl alcohol (153 proof Everclear or
cheaper generic). You'll want to have both of these on-hand, in
spray bottles (clearly labelled so you don't use the toxic
isopropyl for anything except outer surfaces).
- Cover your work area with paper towels and spray the paper towels
with isopropyl. Be extra careful when using any flame!
- Get everything you are going to be using out, and arrange for
quick and easy access while you are working with the yeast.
Your yeast slant and 10mL starter tube should be positioned on
your left, with the torch or alcohol lamp directly in front.
Keep the flame on a medium setting (too high and you burn
yourself; too low and it won't do the job well).
- Loosen both the slant tube's cap/stopper and the 10mL starter
tube's cap just enough to break its grip on its
respective tube.
- Take the inoculation loop in your right hand and hold it like
you would a spoon or fork; run the loop end of the inoculation
loop, and the twisted nichrome wire leading up to the loop, over
the flame until it glows bright orange. Finish at the loop end.
- Now, working over the flame, pick up the slant with your left
hand, and without letting go of the inoculation loop, grab the cap
from the slant tube with your right pinky finger and hand, and open
it (do not let go of the cap when you do this).
- While still working over the flame (until you are completely
finished), put the inoculation loop into the slant tube and push
it under the agar (opposite from the yeast) to cool it (it will
often hiss as it cools rapidly). Then use the loop to take a
small scraping (it only takes one cell) from the yeast
colony on the slant. Remove the inoculation loop from the tube,
keeping everything over the flame (be careful not to torch the
yeast!).
- Once again, flame the open end of the slant tube to destroy any
bacteria that may have gotten into the area of the tube opening,
and then close the tube and set it aside. As you do this, grab
the 10mL starter tube with your left hand.
- Open and flame the 10mL starter tube as you did the slant tube.
- Put the loop of the inoculation loop into the 10mL tube's wort
and stir vigorously. Remove loop.
- Flame and close the 10mL starter tube. Shake vigorously to
aerate and provide oxygen for the yeast.
- As often as is practical, up to as much as every six hours or
so, shake the starter tube and open about a 1/4 turn or less to
allow any pressure that has built up to escape. Once the yeast
gets going really well, shaking will make a definite foam, and
when you vent, you will hear a very distinct hiss, and the foam
level will rise significantly. At this point (which may be as
soon as a 12 hours, or as long as two days; after three
days, worry).
- When your yeast is ready, take one of your prepared starters
in 250mL Erlenmeyer flasks out of the fridge, and let it
filter it through your sanitized coffee filter into another
sanitized 250mL flask (to remove the cold break goo), add your
yeast (again, NO AIR MOVEMENT while yeast is exposed),
and cap off with a stopper and air-lock. After yeast is at
high krausen, repeat, stepping up to the quantity you need to
pitch. Follow the instructions found in
the previous section, on
starters from Wyeast smack packs and White Labs vials, except
of course for the source of the yeast and the amount of wort
you'll need to use to bring it up to your final pitching level.