WSU Thurston County
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Thurston County Extension
Food Safety: Food Preserving
Vacuum-seal Jelly to Prevent Mold Growth
The Olympian, August 5, 1998
QUESTION: There is mold on the top of my jelly, Can we eat this jelly?
ANSWER: When spoilage occurs in jams and jellies, it is usually due to mold growth. Some molds produce toxins that make the product unsafe to consume. You should throw it away. Mold can occur with an imperfect seal, when using paraffin, with a lack of good sanitation and with recipes with too little sugar.
This year, prevent mold spoilage by heating jars of jam or jelly in a boiling water bath using two-piece lids so they are vacuum sealed. You can also prevent mold growth by freezing for long-term storage or refrigerating for short-term storage.
QUESTION: My grandmother always used paraffin to seal the top of the jelly jars. Is this a good practice?
ANSWER: Jelly and jam can easily weep around paraffin and break the seal if it is too soft or stored in a warm place. When there is contact between the jelly and air, there is the potential for mold and yeast to grow and multiply. Additionally, the lack of heat processing in a paraffin-sealed jelly makes spoilage by yeast or mold even more likely.
Washington State University Cooperative Extension recommends the use of canning jars, self-sealing two-piece lids and a five-minute process in a boiling water bath in your preparation rather than paraffin.
QUESTION: Could you explain what perishable food means?
ANSWER: Perishable food is food that can spoil and serve as a growth medium for bacteria. In other words, it's food and food products that must be kept either cold or hot to ensure safety. Not all food has the same potential for bacterial growth or spoilage. Bacteria require temperatures between 40F and 140F, water and adequate food for growth and multiplication. Generally, foods that have a higher protein content and adequate water are considered perishable. They more readily support bacterial growth. Meat, poultry, fish, mil and dairy products, cooed salads such as potato and macaroni and recipes that contain these items are more susceptible to spoilage and bacterial contamination.
QUESTION: Do you have examples of things we can do to increase the margin of safety for picnics?
ANSWER: You can increase the opportunity of serving an consuming quality food at family reunions and picnics in a variety of ways:
Choose items that don't require refrigeration: fruits, vegetables, canned meat or canned fish, snack foods, crackers, butter, jelly, mustard, and pickles.
Cook perishable foods before the picnic and cool them in your refrigerator before you pack the cooler.
Use two coolers, one for perishable foods and one for drinks. Remember the more you open an d close the cooler, the less likely inside temperatures will stay out of the danger zone. Keep thins simple and try to plan for appropriate amounts of food. That way, you won't have to worry about the storage or safety of leftovers.
Put the cooler insider the car, not the trunk.
If you're taking carry-out food, such as fried chicken, you should consume the food within two hours of pick-up, or you can purchase the items ahead of time and chill in the refrigerator before packing them into your cooler.
B. Susie Craig
Area Faculty
WSU Cooperative Extension Thurston County
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WSU Extension programs and employment are available to all without discrimination. Evidence of noncompliance may be reported through your local Extension Office. Cooperating agencies: Washington State University, U.S. Department of Agriculture, and the county of Thurston.
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