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Transcript of SourBeer%memphisbrewers.com/wp-content/uploads/2014/11/Sour-Beers.pdf · Whyis%beersour?% •...
Sour Beer
By Cris,an A. Sierra
What is sour?
• Taste percep,on • Vs Bi9er, Tart, Astringent
Why is beer sour?
• Chemical reac,ons • Metabolism • Op,mal pH and temperature
• Bacteria • Bre9
Sour Mechanism
Sour Taste Buds
Ace,c acid
• Same acid in vinegar • Sharper than lac,c acid • Produced by Acetobacter and Bre9anomyces only when oxygen is present
Funk
• Barnyard • Horse blanket • Damp basement
Lac,c acid
• SoK tangy flavor • Produced by lactobacillus and pediococcus
Sour
• Tart • Acidic • Tangy • pH of about 3.0 to 3.9
Enzymes 101
Substrate
Enzyme-‐Substrate Complex
Transi,on State
Product
Enzyma,c Ac,vity Grain
Enzyma,c ac,vity is Temp & pH dependent
Enzyma,c ac,vity is Temp & pH dependent
Enzyma,c ac,vity is Temp & pH dependent
Bre9anomyces
Yeast Pathways
Bre9anomyces • Produces esters, like brewers yeast • Can break down esters (fruity) • Produces ace,c acid with O2 otherwise no sourness only
funky • More interspecies varia,ons than brewer’s yeast • Pitch 100cells/mL • Pitch into already fermented beer • Alpha-‐glucosidase: dextrin catabolism • Beta-‐glucosidase: glucose/simple sugar catabolism • Cellobiouse: wood sugar • Absorbs nutrients when saccharomyces autolysis • 82 degrees F (growth) about 68 for flavor
Lactobacillus
Lactobacillus
• 104 to 111 degrees F • Homofermenta,ve: only lac,c acid; higher nutri,onal requirments
• Heterofermenta,ve: lac,c acid, CO2, ethanol • Lowers pH to 3.3 to 3.4 • Consume dextrins
Lactobacillus Pathways
Hops
• An,microbial • Inhibits lactobacillus >20 IBUs, aim for < 5 IBU’s
• Inhibits ability to transport sugars and amino acids
• For hops: dry hop aKer souring
Pediococcus
Pediococcus
• Slower working • Sharply acidic at ,mes • Produces diacetyl and exopolysaccharids that can be eliminted with bre9
• Most ac,ve aKer simple sugars are consumed • 86 to 90 degrees F
Pediococcus Pathways
Acetobacter
Acetobacter
• Requires O2 • Consumes ethanol • Produces ace,c acid: vinegar character
Wyeast
• Bre9 bruxellensis • Lactobacillus • Bre9 Lambicus • Pediococcus • Roeselare Ale Blend • Belgian Lambic Blend
White Labs • Berliner weisse blend • Bre9 bruxellensis trois • Bre9 claussenii • Bre9 bruxellensis • Bre9 Lambicus • Belgian sour mix I • Pedio damnosus • Flemish ale blend • Am. Farmhouse • Lacto brevis • Lacto delbrueckii
East Coast Yeast
• Bug Farm • Bug County • Flemish Ale • Farmhouse Bre9 • Dirty Dozen Bre9 Blend • Bre9 bruxellensis • Bre9 anomala • Bre9 naardenensis
BJCP: European Sour Ale
• Berliner Weisse • Flanders Red • Lambic • Gueze
BJCP: Historical Beer
• Gose • Lichtenhainer
BJCP: American Wild Ale
• Bre9 Beer • Mixed-‐Fermenta,on Sour Beer
• Soured Fruit Beer
How to make sours?
• Sour recipes • Sour mashing • Sour starters and pitching rates
• Starches and difficult to digest sugars
• Alcohol content
Guidelines
• 1040 to 1060 • <20 IBU’s • Bo9le dregs • Oak chips • Acidulated malt • Dextrins
Metabolism: Sugars vs Starches
• Unmalted grains • Gela,niza,on • Turbid Mash • Adjuncts: maltodextrins/refined starch
• Cellobiose, maltose, lactose, dextrins, glucose, galactose, fructose
Turbid mash
• Run off liquid through mash tun and boil • Add back at mash out to raise temp of mash • Provides food for bre9/bugs aKersaccharomyces fermenta,on
Gela,nizing unmalted starches
• Mash with near boiling water • Gelitanizes starch • Boil milled unmalted grain then add porridge to main mash
Adjuncts
• lower buffering capacity of wort so pH lowers more easily
• Adding adjucts (sugars) aKer souring feeds the dominant bacteria and Bre9
Blending
• Adds sweetness with fresh malty beers
Miscellaneous
• Secondary vs primary vs barrel
• English ale vs. belgian ale yeasts
• Pitching rates
Sanita,on
• Gaskets • Hoses • Boiling • Loca,on, loca,on, loca,on
The Least You Need to Know
• pH < 4.5 inhibits growth of Enterobacter • ABV > 6.5% inhibits souring • >20 IBU’s inhibits lactobaccillus • Shoot for OG of 1.040 to 1.060 • Starches can be broken down by bacteria and Bre9: ie unmalted grains