Skip to Main navigation Skip to Left navigation Skip to Main content Skip to Footer

University of Minnesota Extension

Extension > Extension in your Community > Rice > County Agriculture Educator > Articles > Resources for safely preserving surplus produce

print icon email icon share icon

Resources for safely preserving surplus produce

It’s the time of year that excess garden produce is stacking up on the countertop, and you may lament that you simply can’t eat it or give it away quickly enough. Preserving your surplus produce may be the solution to your problem. Your preserving options are abundant: can, dry, freeze, pickle, or make jelly. The University of Minnesota Extension website has recommendations for all of these practices. Visit UMN Extension’s website, for specific recipes, guidelines, and other resources; there are plenty to choose from.

UMN Extension’s Food Safety webpage has numerous resources for information regarding preserving produce, along with tips for preserving meat, fish, eggs, and poultry. I mention the webpage because I suspect that the UMN cooking and canning tips may be an underused University resource. These tips and recipes are University-tested and provide safe guidelines for preparing and preserving food based on scientific research.

There are just a few basic principles behind safely preserving food, and they have to do with the concept of preventing spoilage. The high percentage of water in most fresh foods makes them perishable. They spoil or lose their quality for several reasons, including the growth of undesirable microorganisms such as bacteria, molds, and yeasts, the activity of food enzymes, reactions with oxygen, and moisture loss. These issues must be addressed when preparing and preserving food. It is critical that home preservers use up-to-date and credible methods for preserving food, and recipes from books or old, passed-down recipes from before 1994 are not recommended.

When proper preservation practices are followed, they control potential spoilage by removing oxygen, destroying or preventing the growth of undesirable bacteria, yeasts, and molds, and by forming a high vacuum in jars or controlling microbial growth with cool temperatures. Old recipes may not properly accomplish this microbe control and may not recommend the correct amount of acid. Even canned tomato recipes, which you might think would be acidic enough, call for extra acid to ensure a safe level of acidity which is at a pH of 4.6 or less (high acid level). Acidity is vital to prevent the growth of C. Botulinum bacteria, which causes botulism. It is important to follow current recipes which reflect our current understanding of food safety.

Preserving food can be a personally rewarding way to reduce food waste, and the UMN Extension Food Safety webpage provides reputable resources to ensure that your food preservation methods are truly safe. Some of the resources online include: articles, lab-tested recipes, lists of frequently asked questions, instructional videos, mini-module videos, self-teaching handouts, and links to preserving and food safety classes. UMN also offers Cottage Food Producer Food Safety Training and Home Food Preservation courses in person or online.

In addition to the UMN Extension Food Safety webpage, you can find safe preserving practices and recipes by contacting the UMN/ISU AnswerLine at or 1-800-854-1678 (from Minnesota), visiting the USDA-sanctioned National Center for Home Food Preservation  website at, or using Ball Blue Guides dated after 1994.

  • © Regents of the University of Minnesota. All rights reserved. The University of Minnesota is an equal opportunity educator and employer.