Fermented foods safety guidance: A new resource for public health practitioners

Fermented food safety is a shared challenge for many public health practitioners across Canada. While many of these foods are generally safe, emerging fermentation trends such as the selling of fermented foods at farmers’ markets or the preparation of fermented foods at food premises, may exacerbate food safety risks. Assessing the food safety risks of fermented foods can be difficult for public health inspectors (PHIs) who may not regularly encounter them during their practice. To support PHIs and food safety specialists in assessing the food safety risks related to fermented foods, the newly released Fermented Foods Safety Guidance website has been launched by the Canadian Fermented Foods Working Group (FFWG). The FFWG are a group of PHIs, food safety academics, food safety specialists, and industry fermentation experts from across Canada. The group aims to identify and contextualize common fermented foods encountered by PHIs and operators and to develop evidence-based food safety guidance for these foods. This blog post outlines the three chapters that are completed. The group continues to finalize the remaining chapters (see below) and these will be published online when available.

Food safety risks of fermented foods

Fermentation is a range of techniques that are used to preserve and add flavour to foods. The fermentation process produces alcohol or acids that kill harmful bacteria that may lead to food spoilage or foodborne illness. However, if proper fermentation conditions are not met, harmful bacteria may not be adequately killed. An effective fermentation process requires specific conditions to be met including proper sanitation, temperature, and fermentation time. These conditions vary depending on the type of food being fermented and the type of fermentation process being used, which can make assessing food safety risks for fermented foods challenging for public health practitioners.

About the Fermented Foods Safety Guidance

The guidance website is a tool that can be used by PHIs, food safety staff, and owners and operators of food processing facilities. The guidance does not replace or supersede federal or provincial guidance or regulations for fermented foods or food safety. The guidance should be used to supplement and inform decisions related to assessing the food safety risks of fermented foods.

The Fermented Foods Safety Guidance discusses specific food safety risks for common types of fermented foods and provides guidance to mitigate these risks. This includes information that will be useful for PHIs, food operators, and researchers, such as critical limits, critical control points, and food flow charts. The guidance draws on the best available evidence as well as the experience of food safety specialists and fermentation experts.

The Fermented Foods Safety Guidance website includes an introduction to fermented foods and an overview of how fermented foods are described by substrate, fermenting agent, or end-product. It also describes common types of starter cultures such as lactic acid bacteria, moulds, yeasts, and symbiotic cultures of bacteria and yeasts (SCOBY)-based fermentations.

Each chapter of the guidance focuses on a specific type of fermented food and includes:

• The background of the food,
• The method of preparation,
• A food flow chart,
• A review of the potential issues with food preparation, and
• Food safety control points.

The following chapters are now available on the Fermented Foods Safety Guidance website:

• Sauerkraut: a traditional European wild lactic acid fermentation of cabbage and salt.
• Kimchi: a traditional Korean wild lactic acid fermentation of cabbage and salt, including red pepper powder, garlic, ginger, onion, and other ingredients.
• Dosa and idli: a traditional South and West Indian dish made of fermented cereals that are ground and then fermented with salt, wild yeast, and lactic acid bacteria. The dough is fried (dosa) or steamed (idli).
• Plant-based cheese: a fermentation of ground nuts (e.g., cashews) or nut liquids (e.g., coconut milk) made with commercial lactic acid bacteria and added flavour ingredients.
• Koji fermented foods: these include traditional Asian foods such as miso, soy sauce and a sweet beverage called amazake made with rice and cereals, such as wheat or barley. Koji foods are fermented with commercial Aspergillus oryzae molds creating enzymes that break down carbohydrates into sweet (amazake) and savoury (miso, soy sauce) flavours.
• Kombucha and Jun: fermented beverages of Asian and Russian origin made of black tea and sugar (kombucha) or green tea and honey (jun). Symbiotic cultures of bacteria and yeasts (i.e., SCOBYs) are re-used to create these carbonated, vinegar-based flavoured drinks.

What’s next?

The following chapters will be posted on the Fermented Foods Safety Guidance website as they become available:

• Fermented vegetables: including lactic acid bacterial or lacto-based crock ferments such as cucumbers or pickles, as well as vinegar-based preparations of fermented vegetables.
• Fesikh: a traditional Egyptian fish dish that involves drying, salting, and wild lactic acid bacteria fermentation.
• Yogurt: pasteurized milk that is cultured with commercial lactic acid bacteria.
• Natto: a traditional Japanese fermentation of boiled soybeans with commercial Bacillus subtilis.
• Tempeh: a traditional Indonesian soybean cake fermented with commercial Rhizopus.
• Kefir (water and milk): fermented beverages of Russian origin that use a combined fermentation method with lactic acid bacteria, acetic-acid bacteria, and yeasts.
• Fermented sausages: meats that are fermented with commercial lactic acid bacteria, nitrites, salt, and other ingredients.
• Pidan century eggs: a dish that uses alkaline processing, which is not technically fermentation, but uses a microbial culture.

New chapters will be posted on the Fermented Foods Safety Guidance website as they become available.