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
| 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
| 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.