Transcript malt - CSU, Chico

Flow chart for malting and brewing
Harvest
Malting
Steeping
Germination
Kilning
Milling
Oxygenation
Trub removal
Hops
Boiling
Decoction
Infusion
Pitching
Yeast strain
Fermentation
Lagering
Packaging
Conditioning
Mashing
Barley and
Malt processes
Wort production
Conversion of
Wort into Beer
Malting
Barley is received from the
farm in trucks.
Mycotoxin analysis is
performed to determine
contamination levels.
Most maltsters will not
accept barley with over 2
ppm fusarium toxins.
www.crc.dk/flab/danish.htm
Steeping and germination
The dry barley is hydrated to 4546% moisture with repeated
steeping. Additives to steep
water included gibberillins and
calcium hydroxide.
At 45% moisture, the barley has a
small germ tube extending
from it.
The barley is then germinated in
large aerated bunkers at 15°C
It is constantly agitated to
remove heat. After 3-5 days,
the green malt is ready for
kilning.
Enzymes are active at this time.
Kilning
Kilning is a two step process designed to prevent the
enzymes from being inactivated while providing a dry
malt. Low temps 50-60°C are used initially, then
higher temps are used – 80°C.
Enzymes developed during germination and
used during mashing
Amylases: Produce food for yeast and mouthfeel for the beer.
a – amylase is a random a 1-4 cutter.
Cleaves amylose into random pieces and amylopectin
into
dextrins. Temp opt. 70-75°C
b – amylase cleaves off maltose units from starch.
Leaves dextrins. Temp opt 57-67°C.
Glucoamylase – produces glucoses from all starch. Low calorie
beers.
Proteases: Provide nutrients for yeast, aid in foam, can cause haze
At 60°C results in high MW peptides
At 45-50°C results in low MW peptides and amino acids.
Protein rest in decoction mashing to allow proteolysis
b-glucanases: cleave glucans found in the malt. Reduces viscosity of
wort.
Hops
Hops Components
resins
3-20 %
essential oils
0.5-3.0 %
Resins : most important component is alpha-acids
(responsibile for bitterness of hops)
HUMULENE OXIDATION PRODUCTS
Humulene
Humulene epoxide I
Humulene epoxide II
Humulene epoxide III
O
O
Humulene diepoxide I
O
H
OH
Humulenol II