Fermenting Foods Safely

Fermenting your own foods or beverages can be a fun way to add more fermented foods or beverages into your diet. Last month, our post Fermented Foods and Health looked at why fermented foods and beverages are growing in popularity, while this post gives strategies to safely practice fermentation at home. Fermenting and food safety naturally go hand-in-hand since important fermentation steps that must be practiced ensure both a delicious and safe product.

Home Fermentation

Fermenting your own food or beverages can be intimidating because it involves a shift in mindset from getting rid of microorganisms, to respecting and working with the microorganisms. The fermenting microorganisms can be either “wild,” or already on the food (for example: on cabbage for sauerkraut), or added as a starter culture (for example: add to milk for yogurt). When provided a safe and suitable environment for growth, these fermenting microorganisms can outcompete the microorganisms that could potentially be harmful or cause spoilage. Your role is to monitor and control the factors important for microbial growth, or to manage the ecosystem.

Consider these tips as you practice fermenting your own foods:

• Follow a reputable and trusted recipe or resource, and also keep your own records of your process. This helps set the stage for a safe, desirable and repeatable end-product.
• Understand and apply best practices. The food, amount of salt, moisture, oxygen levels, and temperature all play a role in allowing the food to safely ferment.
  • With appropriate oxygen and temperature control, microorganisms, especially lactic acid bacteria, actually digest the carbohydrates in the food and create organic acids, such as lactic acid. These organic acids acidify the product to a pH level below 4.6, which would make it more difficult for growth of harmful microorganisms.
  • Salt is needed to support a suitable fermentation environment in many ferments, especially vegetables. Salt helps set up the environment to favor certain bacterial species over others, as well as block the oxygen exposure. Unlike most fermenting microorganisms, spoilage microorganisms often need oxygen, which is why a head of cabbage just left in the crisper drawer of your refrigerator will rot instead of ferment.
• Always practice proper hygiene. Wash your hands thoroughly, clean and sanitize equipment, and block exposure to pests and potential airborne contaminants.
• When finished fermenting, refrigerate. When maintained safely, fermented products can be kept refrigerated longer than the initial fresh product. The length of time depends on the end-product, plus oxygen exposure or potential contamination from use that might compromise the safety and quality of the product.
• And as always, trust your gut! If something doesn’t seem right, for example an off odor or unusual appearance, don’t taste it. When in doubt, throw it out! Even experienced fermenters have bad batches and need to start with a new culture and/or re-sanitized equipment.

Whether you are determined to start your first or hundredth batch of yogurt, kimchi, sourdough, or kombucha, always be mindful of the needs of your microscopic partners, and enjoy safely creating fermented products.

For more information, please visit the Fermented Foods resources on the Colorado Farm to Table website.