• Lactic Acid — Lactobacillus & kefir cultures
• Alcoholic/Yeast — Yeast & ethanol fermentation
• Acetic Acid — Acetobacter & SCOBY cultures
• Alkaline — Bacillus bacteria
• Fungal/Mold — Koji, Rhizopus, etc.
• Specialty Bacterial — Propionic, aged cultures