Tag Archives: low-acid foods

Your Favorite Salsa Recipe…Is it Safe to Can?

Raw ingredients for salsa

Maybe you inherited a delicious salsa recipe from your father and you’d like to ship it out the entire family, or maybe you got creative in the kitchen with your kids and would love to store jars of their salsa for a surefire snack throughout the school year. But then you wonder: is that unique blend of ingredients safe to can at home? Here are a few reasons why that’s an important question to ask, and a few resources to help answer it.

Cutting tomatoesChopping jalapenos

  • Salsas are a mix of acid and low acid ingredients. Overall pH is what determines if a product is safe to be processed in a boiling water canner. If a salsa is not adequately acidified to a pH of 4.6 or below, then processing in a boiling water canner will not provide enough heat to prevent toxin-production by botulism-causing bacteria. Sufficient, carefully calculated amounts of vinegar or another acid are necessary ingredients for acidification.
  • Without detailed knowledge of the ingredients, proportions, and procedure used for a salsa recipe, there is no way to tell is the product is safe for boiling water canning. Unfortunately, we at the National Center are not able to fund and staff product testing for individual recipes. Here is a link to learn more about the science behind determining the Heat-Processing of Home-Canned Foods.
  • If you are determined to can your own salsa, please call your local Cooperative Extension office and ask if they have contact information for private testing companies. This link will help you Find Your County Office.
  • Fortunately, USDA and Cooperative Extension have a variety of tested recipes and processes for canning salsa at home. Ten different and diverse salsa recipes as well as background information and step-by-step boiling water canning directions can be found in the University of Georgia publication Sensational Salsas. If you want to view the recipes by themselves, follow this link to the NCHFP webpage “How Do I?…Can Salsa”. From there you’ll see that each salsa recipe is also available in Spanish.
  • Some equipment and home preserving ingredient manufacturers also offer more recipes to try, but first do some research to find out if they are indeed reliable companies with tested recipes.

Mango Salsa Raw Mix

Why can’t I can what companies can?

As a home canner looking for new recipes to try out, you might sometimes be inspired by commercial products found on grocery shelves. But even after scouring through all your recipe books, magazines, and online resources there are still some products for which you cannot find home canning recommendations. Why is this? What do these companies have that you don’t?

Well, in summary, companies have two things that home canning does not have: 1) special equipment and 2) lots of money for research.

Commercial facilities have industrial equipment that can reach higher temperatures more quickly than what can be achieved at home. With specialized equipment, they are also able to control the consistency and maturity of ingredients. This control reduces the variability of the canning process, which allows for more reliable research (and therefore more product development) than can be done for home-canning practices.

Companies pay to conduct expensive research in order to determine safe product formulas and processing methods for each and every product. Even if just one ingredient is added to an already approved product, that new recipe must be carefully tested before being manufactured for sale. Acidity levels, water activity, and heat penetration are all critical factors influencing processing times, and these factors vary greatly among different recipes.

Proper studies to establish processing times for both commercial and home-canned recipes are crucial to the safety of canned foods. Without proper processing times, there is significant risk of botulism resulting from under-processed canned foods, especially low acid foods. Experimentally determining safe processing times requires a lot of time and money, and there is no easy formula to take into account the way that each product heats in each canning situation. Commercial and home-canning processes are not interchangeable. That is why there are fewer recipes and processes for home canning than many people would like.

For more information about heat processing of home-canned foods, read this ‘Backgrounder’ by Elaine M. D’sa.

Ummm…what exactly is botulism? (Part III)

Botulism: Surprises

Before moving on to the brighter sides of home food preservation, a few more interesting and perhaps less known facts about botulism:

  • Home canned products may be the most well-known source of botulism, but in recent decades botulism has also been linked to unrefrigerated homemade salsa, baked potatoes in aluminum foil, garlic in oil, traditionally prepared salted/fermented fish, and honey (the primary cause of botulism in infants).
  • This might startle you, but we actually consume C. botulinum spores regularly and they generally do not harm adults. Adult human bodies prevent the growth of spores, such that no toxin can be produced.
  • However, spores have been found to germinate, colonize and produce deadly poison in the intestinal tracts of infants. Therefore, USDA recommends that honey is not given to children under 1 year of age and that fruits and vegetables be washed very well before fed to infants.
  • Clostridium botulinum toxin is among the most toxic substances known.
  • Cases of botulism have been reported in which people showed symptoms only 4 hours after ingestion. The longest time reported between ingestion and illness is 8 days.

Information in the entry comes from the USDA factsheet Clostridium botulinum and So Easy to Preserve.

Umm…what exactly is botulism? (Part II)

Botulism: Prevention

After reading last week’s entry you know where botulism comes from and the effects it has on people. But perhaps even more importantly, are you confident that you know how to prevent it?

There are essentially two ways to prevent botulism: 1) thermal destruction (heating) of spores and 2) inhibiting spores from germinating into toxin-producing vegetative cells.

Even in favorable conditions, C. botulinum vegetative cells and toxin should be destroyed when held at the temperature of boiling water (212°F at sea level) for a relatively short period of time. There are some other inactivation heat processes available for different types of food, also.  However, C. botulinum spores are much more heat resistant and need temperatures much higher than boiling to be killed in  reasonable times.  For home canning, we use temperatures of 240°F or above. It is very important to note that, unlike most bacteria, C. botulinum and other spores are NOT destroyed by normal cooking or boiling procedures. The spores require higher temperatures (240°F or above) that properly operated pressure canners create.

dial=gauge pressure canner

To prevent botulism, use approved processing methods and times as recommended by USDA. Carefully follow recommendations for pressure canning low acid foods. If you are still concerned if you did everything right, you can boil home-canned products in a saucepan on the stove for ten minutes before serving (add one minute more for each 1,000 of elevation).

Also remember that C. botulinum spores cannot germinate and then produce the toxin in pH levels of 4.6 or below. Acid foods and properly acidified food products have pH levels equal to or less than 4.6, so the toxin formation is prevented. Examples of acidified foods include pickles to which vinegar is added and salsa to which lemon juice is added.

pickled green beanspeach apple salsa

You can further help prevent botulism and other foodborne illness by practicing general food safety; refrigerate all leftovers within 2 hours after cooking, and after just one hour if temperature is above 90°F. Discard, without tasting, any containers of food that are swollen, bulging, leaking, or cracked. Also immediately discard any product that spurts liquid or foam from a container once opened (unless it’s carbonated and shaken, of course).

Information in the entry comes from the USDA factsheet Clostridium botulinum and So Easy to Preserve.