Safe canning for food operators
Canning is growing in popularity as people look for simple ways to preserve fresh, seasonal, and locally sourced foods, often with more environmentally friendly packaging.
To keep canned foods safe, operators must follow proper preparation methods and meet Ontario’s food safety requirements under the Health Protection and Promotion Act.
If you’re starting a canning business in Peel
You must notify Peel Public Health at least 14 days before opening.
Canning must be done safely
Canning is a food preservation method that uses heat treatment, often combined with controlling acidity (pH) and water activity. Food is stored in hermetically sealed containers. This process destroys bacteria, yeasts, molds, and enzymes that cause spoilage or illness. The combination of heat and airtight sealing creates a vacuum, allowing canned foods to remain safe and shelf-stable for long periods without refrigeration.
Improper canning can lead to botulism, a life‑threatening illness caused by Clostridium botulinum (C. botulinum), as well as other foodborne illnesses.
Canning methods fall into 2 categories: high-acid (lower risk) and low-acid (higher risk). Each requires a different heat‑processing technique to prevent the growth of C. botulinum.
Boiling water bath canning (100 C)
This method involves submerging filled jars into boiling water (100 C) for a set processing time, which can change based on the food’s type and acidity.
- Used for: High‑acid or acidified foods with a natural equilibrium pH less than or equal to 4.6
- Examples: Fruit jams and jellies, vinegar‑based pickles, relishes
Pressure canning (116 to 121 C)
Pressure canning uses a pressure canner to heat jars in a sealed chamber where temperatures exceed boiling, typically 116 C to 121 C by increasing internal pressure.
- Used for: Low‑acid foods with a pH > 4.6
- Examples: Vegetables, meats, soups, chutneys, mushrooms, chili sauces
Start with a validated recipe
A validated recipe is one that has been scientifically tested to ensure the final product is safe to eat. It provides precise instructions such as required ingredients, preparation steps, processing methods, heating times, and temperatures and includes key safety factors like the correct acidity (pH) and water activity. When followed exactly, a validated recipe consistently produces a shelf‑stable product that won’t spoil or cause illness.
Where to find validated recipes
To ensure canned foods are safe, all low‑acid/higher‑risk products must be made using a trusted, scientifically tested (validated) recipe. These recipes come from reliable, science‑based sources that have tested processing times, temperatures, container sizes, and acidity levels.
Examples of trusted sources include:
Low‑acid foods require extra precautions
Low-acid (high risk) foods have a pH greater than 4.6. Low‑acid foods must always be canned using a scientifically tested (validated) recipe and processed in a pressure canner that can reach high temperatures (116 to 121 C). These foods must be heated at the correct temperature for a specific time, usually 20 to 100 minutes, and both time and temperature must be carefully monitored and recorded.
If you sell or serve low‑acid canned foods
Food operators selling or serving low‑acid canned products must:
- Have a Food Safety Plan that documents how the product is prepared safely.
- Provide lab test results for pH and water activity (aw) for low‑acid or higher‑risk foods, if requested by your public health inspector.
Using your own recipe must be done safely
If an operator wants to use a non‑validated recipe such as a family recipe, they are responsible for having it validated by an accredited laboratory. Once validated, the recipe must be followed exactly as written, with no changes to ingredients, quantities, equipment, or processing steps. Validation test results should be reviewed and kept on file by the Public Health Inspector (PHI).
A list of accredited laboratories is available through the Standards Council of Canada.
Low‑risk and high‑acid canned products
For high‑acid (low‑risk) canned products, shelf‑stability testing through an accredited laboratory is required.
Shelf‑stability testing is a controlled laboratory assessment that evaluates whether a product remains safe, high‑quality, and suitable for eating for its intended shelf life under normal storage conditions.
A food safety plan should identify potential food safety hazards and outline the controls needed to reduce the risk of foodborne illness.
Operators should work with their Public Health Inspector to ensure they have a complete and appropriate Food Safety Plan in place for their products.
Access the food safety plan template
Clean and sanitize
- Wash hands with soap and warm water before and after handling food.
- Wash all fruits and vegetables including items with rinds before preparing them.
- Clean and sanitize work surfaces, utensils, and equipment throughout the entire canning process to prevent cross‑contamination.
- Sterilize jars by washing them in hot, soapy water and boiling them as directed in your recipe.
Equipment
- Use separate cutting boards: one for washed produce and another for raw meat, poultry, or seafood.
- Use only new self‑sealing lids and ensure the sealing compound is intact. Screw bands may be reused.
- Inspect jars to make sure they are free of cracks, chips, or defects.
- Discard any rusted or dented screw bands.
Cook
- Use only current, tested, and validated canning recipes.
- Do not substitute jar sizes, ingredient amounts, or equipment specified in the recipe.
- Use the correct heat‑processing method based on the food’s acidity.
- During processing, ensure recommended temperatures are reached and maintained.
Labelling requirements
All products must be clearly labelled with:
- Lot numbers
- Labels indicating ingredient source
For details, refer to CFIA food labelling
- Home canning safety - Canada.ca
- Home canning reference document - Public Health Ontario