What Can You Change in a Canning Recipe?

An unsafe practice is making up your own canning recipe or changing ingredients in a tested recipe. Changes could dilute the acidity of the product and can cause botulism poisoning.

What Determines the Time and Amount of Heat Needed in Processing Canned Food?

• Acidity of the food. Adding extra onion, peppers, or other vegetables to salsas and tomato products dilutes the acidity of the product. Never increase the total amount of low-acid vegetables added to the product. Reducing vinegar in salsa or pickled products may result in the contents in the jar being low acid. Vinegar and bottled lemon juice are the high-acid ingredients, making them safe for water bath processing.
• Density of the food. Starchy lima beans take longer to process than more porous green beans.
• Size and shape of pieces of food in the jar. Whole versus crushed tomatoes.
• Water activity. Sweet pickles versus corn.
• Rate of heat penetration. Adding extra starch or thickeners to a recipe changes the rate of heat penetration into the product and can result in undercooking.
• Size of the jar. Use the size jar specified in the recipe.

Changes that are Safe to Make in a Recipe:

• The salt level in anything except canned pickles and sauerkraut
  • Salt is only added for flavor in vegetables, meats, and soups. It is not a safety issue to omit the salt in these foods.
  • The correct salt concentration is essential in fermented pickles and sauerkraut. Don't experiment there.
• The sugar level in syrup used for canned fruit.
  
  • However, sugar does firm the fruit and preserve color.
  • It is safe to can fruit in juice or water, but you may notice a difference in quality.
• Cider vinegar and white vinegar can be used interchangeably.
• In salsa recipes, it is safe to replace vinegar with lemon juice but not vice versa.
• It is okay to decrease any vegetable in salsa except tomatoes and to substitute bell, long green, or jalapeno peppers for each other as long as the total amount is not increased. 
• The types and amounts of dried spices and herbs may be changed, but do not add extra fresh herbs to recipes.

References

LaBorde, L., Zepp, M. & Hirneisen, A. (2019, September 3). "Let's Preserve: Ingredients Used in Home Food Preservation."  Penn State University.

Powers-Hammond, L. (Revised 2014). "Salsa Recipes for Canning."  A Pacific Northwest Extension Publication, PNW 395. Washington State University.

Zepp, M., Hirneisen, A. & LaBorde, L. (2023, March 1).  "Let's Preserve: Basics of Home Canning." Penn State University.