Y E AS T S T O C K
P HOT O S BY T RAS K B E DO RT HA
THE YEAST CONNECT
Home brewers collab and reculture
I
n ancient civilizations, the transformation of
sugar into alcohol was a ritual performed by
diviners and seers. Vats of grape juice and
sweet grain nectar were left before altars,
prayed over by priests and, if given the proper
time and alignment, would morph into a
satiating and consciousness-altering beverage.
The ancient Sumerians took their beer with a
hefty dose of spirituality.
These days, however, home brewers and
commercial brewers alike have a slightly different
relationship with their beer. Not only do they have
access to a plethora of different yeast choices, but
many commercial brewers like Ninkasi keep close tabs
on their yeast by way of labs and chemists. Commercial
breweries also tend to have so much yeast that it’s
spurting out of their tanks by the gallon.
Yeast, as any home brewer knows, is the most
expensive ingredient involved in the brewing process.
So nowadays it’s standard practice for a homebrewer
to sterilize a Mason jar, bring it down to a local brewery
and get a free batch of house yeast.
Why does this hook-up exist? Why would a mighty
commercial brewer take time away from brewing to
help some mere homebrewer?
“It’s definitely related to Jamie’s home brewing
experience and his neighborhood-friendly methodolo-
gy,” Ninkasi cellar supervisor Louie Carter says. He is
referring to Jamie Floyd, Ninkasi co-owner.
Ninkasi started with a standard English ale yeast,
Fullers, and has been selecting the best qualities in that
yeast ever since. This yeast is also noticeably different
now than when it was first being cultured, no doubt
swayed and morphed by the environmental conditions
of the Whiteaker.
4 EUGENE WEEKLY’S STATE OF SUDS 2012
BY A ND R EW HI T Z
“Generally, we’ll select the healthiest or best-
performing, best-tasting yeast,” Carter says. “If it
coincidentally goes up above our normal 10-20
generations, then we might keep it [to reculture with].”
In brewing, a generation is equivalent to one batch
of beer. After the yeast has completely metabolized all
possible fermentable sugars in a batch of beer, it can be
used for reculturing another batch. For Ninkasi, this can
happen nearly 20 times before they deem the yeast
unviable and start a new yeast culture from a library of
yeasts. Yes, that’s right, they have a library of yeasts.
“We have a lab here, and every time we pitch we’ll
do a cell count and viability check and that’s mostly
what we base our preferences on when we harvest,”
Carter says. “We also have the beginnings of a yeast
bank. So we basically have our own library of whatever
yeasts we want.”
Selecting strains of yeast ensures consistency in
brewing and, at near craft-brewing size, as Ninkasi is,
it’s a necessity.
“I would say that [the yeast] has adapted to our style
of beers,” Ninaksi head brewer Mark Henion says.
“With the higher hop loads and alcohol levels, I think it
is fair to say only the strongest will survive.”
Ninkasi’s yeast is as domineering as the brewery’s
beers are delectable to the palate. For home brewers,
that means that fermentation time, depending on
yeast-to-wort ratio, will be shorter, and attenuate well.
For most brewers in the Northwest, hopheads and the
like, that’s exactly the desired effect. ■
L A B M A N A GE R D A N A GA R V E S AT N I N K AS I
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