I wanted to share this cool article with you from a trusted friend and mentor.
SOUR BEER
Immaculate Fermentation: Science, not
Sorcery
By Julia Herz "Craft Beer Coordinator Brewers Association"
Spontaneous
fermentation—what I am hereby referring to as nothing short of
"immaculate"—is an age-old practice, first by accident and then by
intention, that truly puts Mother Nature at the helm of brewing
magic. Ales are fermented with wild yeasts—from an open window, for
instance, or already residing in a barrel—rather than cultivated ones such as Saccharomyces
(brewers yeast).
The
newly published Oxford Companion to Beer(1) sheds some light on the
distinction between wild beers and sour beers, from a master of both, Vinnie
Cilurzo of Russian River Brewing Company.
"'Wild
beer' is generally used to describe any beer that displays the earthy
characteristics of Brettanomyces yeast strains, regardless of whether
the beer is a light golden ale or a strong dark stout. If the brewer adds
acidifying bacteria to the beer, it is termed a 'sour beer.'"
Sometimes
the finished version is blended with an intentionally inoculated beer. But to
be wild, to me, some part of that beer had to be spontaneously fermented.
A
myriad of flavors and aromas evolve because airborne (or other) funk found a
batch of beer and fermented its barley sugars. Again, wild beers are not
intentionally inoculated with yeast that has been '"wrangled" in the
laboratory. On a day-to-day basis most brewers, brewery quality control
professionals, and even some biochemists are yeast wranglers. However there are
also rogues who dabble in the wild side.
Sour and the Wild Side
When
sampling these beers, the sour descriptor comes up often. When it comes from
acidity, sourness in beer helps heighten and brighten food it is paired with.
This, by the way, is also why we use so much salt on our food. Both salt and
acidity help food flavors POP. Sour or acid in a craft beer is the yin to the
yang of the sweetness in foods. Try a sour beer with and without food and
you'll see what I mean. Add wild funk into the mix and you’ve got incredible
complexity to contrast and heighten much on the gastronomic side of the world.
Lucy
Burningham featured the topic of sour beers in a 2010 New York Times
piece, "Sour Beer Is Risky Business, Starting With the Name," where she states "...for
the brewers of sour beer, and its fans, the wait is worth it."
If you
travel in beer circles that go beyond the American light lager, then perhaps
you too have experienced sour or wild ales. The author of Wild Brews,
Jeff Sparrow, explains it this way, "The character of wild beers arises
not so much from the ingredients, but from the environment of the brewery: the
air, the walls, the wood, and the casks. A unique combination of environmental
conditions (winemakers call this terroir) present in every place where beer is
produced determines the character of a wild beer."
Recognized Styles of American Sour Beers
These
styles often have spontaneously fermented versions. Check out the Brewers Association's 2011 Beer Style Guidelines for further details.
·
Sour
Ale
·
Bière
de Garde
·
Lambic
·
Gueuze
·
American-Belgo
Styles
·
Brett
Ales
·
Wood/Barrel
Aged Ales
·
German
Style Sour Ales
·
Leipzig-Style
Gose
·
Old
Ale
·
Saison
·
Flanders
Style Red
·
Flanders
Brown
The Organisms Behind the Funk
So how
do these beers become immaculate and actually ferment without the manual
addition of wrangled yeast? They have made it to the promised land by gaining
alcohol as a result of wild yeast and microorganisms such as Brettanomyces,
Lactobacillus and Pediococcus.
Brettanomyces: A wild yeast.
Common in: Brett Ales, wood/barrel
aged ales, Leipzig-Style Gose, Bière de Garde, Lambic, Gueuze, Flanders, Old
Ale
Descriptors: Horsey, goaty, leathery, phenolic and light to moderate and/or
fruity acidic character
Lactobacillus: A microorganism that produces lactic acid and
carbon dioxide. Lactobacillus is how we get sauerkraut (fermented
cabbage) and is also what sours milk to give us the gift of creamy yogurt.
Common
in: Berliner Weisse, Flanders beers, Saison
Descriptors : Tart, sour,
tang, lactic acidity
Pediococcus: A microorganism that produces lactic acid and
diacetyl.
Can exist in Lambic and
Gueuze
Descriptors: Lactic acidity plus possible buttered popcorn or
butterscotch aroma and flavor
Acetobactor: A microorganism that produces acetic acid.Those
persistent little fruit flies you see in winery tasting room are carries of Acetobactor!
Common in: Lambic, Flanders Red,
and wood-aged beers
Descriptors: Vinegar, pickles, solvent qualities
These
beers are often more acidic (have a lower pH) than most styles. That's where
the sour, tart and mouth-puckering characteristics come from. Normally, 4.0-4.5
pH on the 0-14 scale of acidity to alkalinity is what to expect. Wild ales most
often are in the 3-ish range of pH. For perspective, wines are mostly more
acidic than beer and have a lower pH, rarely exceeding 4.0.
The Immaculate Explained
Whatever
the characteristics, the process takes guts, passion, and practice on the part
of the brewer, and a little mojo from Mother Nature. Many imported examples exist
that are worthy of study, but these are modern beer times with New World U.S.
craft brewers venturing beyond their Old World mentors. Here are a few examples
of these gems described by their immaculate creators themselves.
Beatification
Brewmaster
Vinnie Cilurzo explains: We start out with a sour mash in our mash tun on a
Friday night. On Saturday, we go back into the brewery and run the wort
(unfermented beer) off to the kettle just as we would do for a non-funky beer.
In the kettle, we use aged hops and sometimes boil for as long as three hours.
During this period, we remove the spent malt from the mash tun and rinse it out
with cold water to remove all the residual grain.
Once
we are done with the kettle boil, we’ll heat exchange the wort back to the mash
tun and let it sit overnight. During this period, the wort will pick up some of
the bacteria that was left behind from the sour mash. On Sunday morning, we’ll
remove the wort from the mash tun and fill used Russian River wine barrels that
once housed other sour/barrel beers. The barrels are moved into our barrel room
where they will ferment (hopefully) at 62°F. The beer at this point is called
Sonambic, our term for 100-percent spontaneously fermented beer. We’ll make
several batches of Sonambic a year and pull from several batches to blend and
make Beatification.
Petite
Sour Wild Ale
Crooked
Stave's Chad Yakobson explains: Nothing quite like it exists as far as I know.
The beer is a blend of two beers and two brewing traditions. The first is the
base beer, a rustic farmhouse-type ale with 50-percent wheat base and fermented
in our oak foeder. This portion of the beer is primary fermented with Saison
yeast which we have added to the fermentation. During fermentation, Brettanomyces
and Lactobacillus naturally present in the oak foeder start to take
over in the beer, developing their flavor characteristics.
The
second beer blended into the foeder after primary fermentation is a very
traditional Berliner Weisse-type beer produced completely from spontaneous
fermentation (the wild part of the beer). We don't boil the wort and instead
collect it into the kettle without heating and then transfer it to the
fermenter where it sits for about 10 days as it naturally sours and ferments
from the indigenous microbes present on the malt and in the brewhouse. The idea
behind this brew is to blend a rustic Farmhouse wheat-type beer with
spontaneous German souring methods to produce a crisp sessionable table beer
coming in right around 4.5 percent ABV.
Flor
de Lees
The
second beer, which is not available yet, is Flor de Lees. This is our Colorado
indigenous sour. Many of the details are under wraps for the moment, but we
start fermentation with a fruit grown here in Colorado known for its great
microflora. The fruit is macerated after being freshly picked and added to a
15-barrel batch of wort in our oak foeder with the natural microbes from the
fruit responsible for 100-percent of the fermentation. The beer is then racked
into barrels to age. We plan to blend two- and three-year-old sour beer to
produce something similar to the Gueuze of Belgium but with a Colorado
identity.
Coolship
Project
Allagash's
Jason Perkins explains: The Coolship project started four years ago, modeled
after how lambic beers are traditionally brewed in the Senne Valley and
Brussels. A coolship is a large, shallow pan used to cool wort overnight using
outside air temperature. During the cooling process, naturally occurring yeast
from the air inoculates the wort. In the morning, the cooled wort is
transferred into barrels where the fermentation process begins.
Ingredients
for the base lambic are: Pilsner malt, unmalted wheat (40-percent of grain
bill), aged hops, and, yes, it is all fermented by Mother Nature. During the
brewing process, each batch does go through a decoction mash where we will not
only boil all the ingredients together, but we pull off some of the unfermented
wort and boil it separately there by concentrating it further, and then blend
it back into the overall batch.
US Sour Beer Producers to look out for:
- · Russian River Brewing Co. – Santa Rosa, CA
- · Avery Brewing Co. – Boulder, CO
- · Jolly Pumpkin Artisanal Ales- Dexter, Michigan
- · Lost Abbey Brewing Co.- San Marcos, CA
- · New Belgium Brewing Co.- Ft. Collins, CO
- · Cascade Barrel House- Portland Oregon
- · The Bruery- Placentia, CA
- · Crooked Stave Artisanal Ales. Denver, CO
- · Boulevard Brewing Co. Kansas City, MO
- · Odell Brewing Co. Ft. Collins, CO
- · Goose Island Brewing Co. Chicago, IL
- · Allagash Brewing Co. Portland, ME
- · New Glarus Brewing Co, New Glarus, Wisconsin
International Sour Beer Producers:
- · Brasserie Cantillon
- · Brouwerij Drie Fonteinen
- · Brouwerij Lindemans
- · Brouwerij Timmermans John- Martin
- · Brouwerij Girardin
- · Brouwerij Van Steenbergef
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