Chocolate and Coffee Fermentations

“Sweatings”

Fermented juice (made up of ethanol and acid) from the (sugars in the) mucilage (ethanol and acetic acid liquid pooped out)

• Pectinases break long sugar/protein chains that hold moisture and break it to release the liquid

• We need to do this to dry them out

“Cut Test”

To check if bean has been fermented long enough, color

Considerations for Flavor - Fermentations

Drying and roasting have largest effect on flavor than fermentation

Why is this different from other fermentations?

Fermented substrate is not consumed

Microbial Stage in Cocoa Ferments

1. Yeasts —> Ethanol peak

2. LAB —> Lactic acid peak (from flies)

3. Acetic acid bacteria —> acetic acid peak (aerobic) and temp peak

• Eat the ethanol from yeasts

Metabolite Succession

• Glucose and fructose main sugars

• Citrate also consumed early on

• Ethanol (alcohol) seen FIRST

• Mannitol from fructose, to combat acidic environment

Graham Fleet

Yeasts contribute to essential for proper flavor

• He fermented chocolate in presence of yeasts and bacteria and addition of natamycin (anti-fungal)

• People didn’t like yeastless (antifungal) fermentation

• For LAB nisin (antimicrobial, bacteriocin) and lysozayme (bursts open cell)

  • When bacteria was absent people liked it more

Coffee Process

Different: wash/clean cherries, uses an inoculant, and uses dry or wet processing

• Wet processing uses fruit without skin and part of pulp

Why do a Coffee Bean Fermentation?

• Fermentation goal —> mucilage is degraded whole fruit is dried to low moisture

• Fermentation microbes produce enzymes that depolymerize and hydrolyze the pectin in mucilage

• Removiung mucilage facilitates drying and produces metabolites that go into interior of the coffee bean

• Can prevent problematic fungi such as ochratoxin producers (like cassava)

Microbes and Terroir

Microbial makeup will be different based on where the fermentation happened