Food Safety and Preservation

What's New? Get updates on food safety issues that affect you today.

Resources: Get handouts and instructions on how to prevent food borne illness, store and preserve food to eat later.

Frequently Asked Question on Home Preserving Food: Why didn't it seal? Where did the liquid go? Many problems with home preservation are the result of using improper equipment or methods. To start DO NOT use recipes or methods written before 1994.

What's New?

11/2/09  Holiday Food Safety Website
Ideas and resources on how to have a safe, fun, easy and delicious holiday celebration at home.

10/25/09  Turkey Fact Sheet from OSU    Spanish Version
Get your questions answered on how to defrost, stuff and cook your turkey without getting sick.

Holiday Food Safety Hotline -1-800-354-7319 Get your questions answered on how to handle holiday foods safely including turkey preparation. 
Monday, November 16-Thursday November 19 and Monday, November 23-Wednesday, November 25. 9:00 am - 4:00 pm. Staffted by certified Volunteers and Extension Staff.

10/09 Food Safety Tips on Holiday Eating 
Parties, family dinners, and other gatherings where food is served are all part of the holiday cheer. But the merriment can change to misery if food makes you or others ill.

10/09  Troubleshooting Guide for Canning and Food Preservation 

Home Food Preservation: Frequently Asked Questions
Source: University of Minnesota Extension Service, Updated July 2009

Jars Did Not Seal 
-Use of jars other than official canning jars and/or lids.
-Chipped or uneven rim on jar.
-Using one-piece caps instead of two-piece lids.    
-Screw bands are rusty or bent, causing poor contact.
-Bands not screwed down tightly or too tightly processing. (Turn until you meet resistance, then turn it one-quarter turn.)
-Rim on jar not clean. (Wipe rim well befor putting lid on)
-Liquid leaks out of jar during processing, leaving food particles on to the sealing edge.
-Insufficient heat during processing – air not removed from jar so a vacuum seal never forms (Remove air by inserting a rubber spatula or plastic knife inside the jar gently lift food to remove trapped air)
-Lids were improperly prepared before placing them on rims. (Follow manufacturer’s directions to prepare lids)
-Rapid, forced cooling of a pressure canner can cause a rapid pressure and temperature change inside the canner, causing the liquid to “boil” out of the jars, leaving particles on the sealing rim and unsealing the jars. (Canners should not be forced into cooling rapidly)
-Insufficient processing of raw-packed food – the air may not have been completely driven out of the food, leaving residual air in the jar so the seal does not form.
-Use of canning procedures which are not recommended, such as open-kettle canning, microwave canning and oven canning.
-Incorrect amount of headspace.
-Failure to clean the rim before sealing.

Reprocessing Procedure If a lid fails to seal on a jar, you have 3 options:
1) Remove the lid and check the jar-sealing surface for tiny nicks. If necessary, change the jar, add a new, properly prepared lid, and reprocess within 24 hours using the same processing time.
2) Adjust headspace in unsealed jars to 1½ inch freeze instead of reprocessing.

3) Refrigerate unsealed jars and eat canned product within seven days of refrigeration 


Food Loses Liquid During Processing

-Jars filled too full (leave recommended headspace, may need to increase some at higher elevations)

-Fluctuating pressure in a canner.

-Forced cooling of a pressure canner.
-Jars packed too tightly.
-Removed jars from water bath canner too quickly. (After removing cover, let jars sit 5 minutes in canner before moving to reduce boil overs and ensure a tight seal.)
-Removed jars from canner too quickly. After pressure returns to 0 and weight is removed, let jars sit in canner for 10 minutes before removing.
-The canner stood too long after pressure returned to zero.
-Not exhausting pressure canner long enough. Allow steam to escape for 10 minutes before closing vent/valve.
-Starchy foods absorb some liquid. Water not 1 inch over jar lids during process.


Food Turns Dark (Not Spoiled)
-Insufficient processing time.
-Processing temperature too low – water not at a full boil at beginning of processing or drops below full boil during processing.
-Water not 1 inch over jars lids.
-Packing foods raw that should be precooked (pears).
-Liquid loss during processing, causing fruit at the top to be out of the liquid.


Food Spoils
-Processing at an incorrect temperature due to: Inaccurate pressure canner gauge (Dial gauges should be checked every year. Free testing available. Contact your local Extension Office.)
-Failure to exhaust canner.
-Failure to make altitude adjustment. (In Klamath, process at altitudes between 4000-5000)
-Heat source fluctuates – inaccurate pressure or fluctuating pressure.
-Water not at a rolling boil when jars are put into canner.
-Water not covering jar caps by 1 inch throughout processing.
-Water not at full boil throughout processing.
-Not processing long enough.
Use of canning procedures or recipes which are not recommended or haven't been tested for safety.

-Improper cooling of jars after processing.
-Failure to remove jars from canner when processing time is up (or when pressure gauge reads 0).
Failure to set jars at least 1 inch apart during cooling.
-Covering jars which retains heat – vacuum does not develop.
-Attempting to cool either the canner or the jars very rapidly.
-Using damaged (freeze-damaged), spoiled, under-ripe or over-ripe food – the pH may not be correct for the type of processing you used (water-bath vs. pressure).
-Ingredients were added that were NOT in an approved recipe. 

Fruit or Tomatoes Float or Separate from Liquid
-Using overripe fruit.
-Packing fruit too loosely.
-Syrup too heavy. 
-Processing too long – destroys pectin.
-Processing at too high a temperature (pressure canner).
-Raw packing – food contains a lot of air.
-Smashing or pureeing food prior to heating it activates enzymes which break down pectin in the juice so the food pieces are lighter and rise to the top. (Heat or crush while heating any food to   be pureed or food to be packed in its own juice to help prevent separation.)
-Enzyme changes during handling causes separation of juice (especially tomato).   (Heat tomatoes quickly to simmering temperatures.)

Sediment in Jars (not necessarily a sign of spoilage)
-Starch in vegetables like peas and dry beans.
-Minerals in water. (Use soft water.)
-Fillers in table salt. (Use pure or refined canning salt.)
-Yellow sediment in green vegetables or onion (natural occurrence).
-White crystals in spinach (natural occurrence).
-Overripe fruit.

Discoloration in Canned Foods
-Overcooking or heating at a higher temperature in hot-packed products.
-Excessive heat changes all natural food pigments
-Very dry, hot weather, fruit often turns pick (natural occurrence). 
-Red pigments in beets fade if the beets are overcooked before canning or over-processed during canning.
-Garlic has an iridescent greenish or purplish coloring, this is the result of using immature garlic – it -was not completely dry.
You can eat the food if the liquid is clear, the odor is natural, and if you used the recommended processing methods, time and temperature.




Share this