Fermentation Guidelines Factsheet

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It is crucial that good manufacturing practices including cleanliness and proper hand washing be meticulously followed during all stages of the fermentation process. These practices include:

  • During processing, thoroughly wash fresh produce, the preparer's hands, cutting utensils/boards, and all containers.
  • Select vegetables that are sound, undamaged, uniformly sized and at the proper ripeness.
  • Fermentation vessel must be located in a secure location during fermentation.
  • Culture should not be backslopped.
  • The absence of oxygen is required during fermentation. Preparer must cover product with liquid to exclude air during fermentation. Seal the fermentation vessel to exclude oxygen and ensure anaerobic conditions.
  • If product becomes discolored (pink or dark) it should be discarded. This discoloration indicates spoilage.
  • Detailed records during production of temperatures and pH are required.
  • Equipment calibrations are required and should be documented.
  • Retain records for 2 years (varies for different products).
  • Once fermentation is complete, keep product under refrigeration (less than 40 °F).
  • Fermented foods that are processed for shelf stability require product testing by a process authority to establish an adequate thermal process specific to the product.
  • Fermented foods are not considered acidified and therefore do not require registration with the FDA to sell.

Fermentation Processes

Fermentation Guidelines (Optimum Salt Level)
Food Optimum Salt Level Optimum Temperature Range Time Range to Complete Fermentation
Cucumbers 5-8% (Brine) 59-89.6 °F
Cabbage 2.25% (by weight of cabbage) 60-70 °F *5-6 weeks
70-75 °F *3-4 weeks
Kimchi 4-6% (brine or by weight) 50-64 °F *5-20 days
Fruit 2-3% (brine or by weight) 50-59 °F 2-6 weeks

* Fermentation is complete when product reaches a pH below 4.6

Fermentation Guidelines (Starter Culture)
Food Starter Culture Optimum Temperature Range Time Range to Complete Fermentation
Kombucha Heat to rolling boil before adding 75-85 °F 12 days minimum

Guidelines for Kombucha production:

  • If using a dehydrated starter culture, such as SCOBY, the manufacturer's guidelines must be followed for rehydration with vinegar.
  • Fermentation may be performed at lower temperatures. If this is done, holding times must be extended to appropriately compensate for reduced microbiological respiration due to lower temperatures.
  • The pH must be tested by a Process Authority.
  • Must be lab tested to confirm that finished product contains less than 0.5% alcohol by volume.
  • Sterile bottles must be used if any bottling occurs.
  • Product should be kept refrigerated (below 40 °F) once fermentation is complete to avoid further alcohol production.
  • Product should be labeled as "keep refrigerated"

Additional fermented foods may be evaluated on an individual basis.