Loss of Liquid in Home Canning - Home Canning Problems Explained: Loss of Water or Syrup Solution in the Jars During Canning
This month's notes: April 2014: Spring is just around the corner. Strawberries are here in Florida, Texas and California, next in late March and April for much of the South, then in May for most of the country and June in cooler northern areas. See how easy it is to make strawberry jam or strawberry-rhubarb jam!
Why did my jars lose so much water? The liquid level in some of the jars went down by half! What causes water loss in home pressure canning?
Sometimes after processing, some of the water or canning liquid in the jar is lost and doesn't cover the product. Lost water is most common when pressure canning, especially with starchy foods. Typical causes and solutions are:
- Packing the food too tightly or too loosely in the jar. Snug but not hard packed would be the best way to describe optimum packing.
- Starchy foods, such as corn, peas or lima beans, absorbed all the liquid. Use more liquid with these starchy vegetables.
- The jars filled too full (too much vegetable/fruit compared to the amount of liquid).
- Water bath canning only: The jars are not totally covered with boiling water during the boiling water bath processing.
- Pressure canning only:
- Fluctuating pressure in the pressure canner.
- Cooling too quickly. Let pressure return to zero gradually, avoiding the sudden release of pressure through the vent. Do not hasten the cooling with cold water. (If the canner cools too quickly while the contents of the jar remain at a much higher temperature, the liquid will boil over. The contents of the jar and the canner have to cool down gradually from 240°F to 212°F. The "coming down" period should be gradual and even.)
- Pressure canner not sufficiently exhausted.
- Opening the petcock or removing the weight before the pressure has returned to zero. (When the pressure has returned to zero, open the petcock very cautiously and if steam escapes, close and wait a few minutes. This avoids cooling the atmosphere around the jars too fast which causes liquid to boil over.)
- Letting the canner stand too long after pressure returned to zero. It should be opened within a couple of minutes after it returned to zero pressure.
- Removing the jars too quickly after removing the cover. Let the jars remain in the canner a few minutes after removing the cover, or until the boiling in the jars is less vigorous.
- Having an inaccurate dial pressure gauge that does not return to zero. (The petcock in this case could be opened too soon or not soon enough.)
- Leakage of steam from pressure canner.
- Air naturally entrained within the fruit or vegetable that wasn't released (generally this happens more with raw pack than hot pack)
- The food was not heated prior to filling (when using the Raw pack method). Said another way: Liquid added to cover cold raw food was not hot enough when poured in the jars and placed in canner.
- Air bubbles were not removed prior to sealing the lids and rings on the jars. Of course you can't get every single air bubble or tiny ones, but do get the large ones out using a knife or bubble freer.
- Headspace problems: Leaving wrong amount of headspace when filling jars. Follow the directions in each recipe; in general, leave:
1 inch headspace for LOW ACID foods such as most meats and vegetables.
1 ¼ inch headspace for chicken and rabbit.
½ inch headspace for HIGH ACID foods such as fruits, tomatoes, and fruit juices.
¼ to ½ inch headspace for pickles and relishes as directed.
¼ inch headspace for jams and jellies.
- Not removing particles of food, seeds, seasonings, or pulp of fruit from top of jar or threads with damp paper towel before putting on lid. Particles left on rim of jar can because of lid sealing, then loosening..
- Screwing band too tight can cause lid to buckle. A band MUST be tight enough to hold the rubber sealing compound closely against the top of the jar. However, if the band is forced as far as it can be turned with a strong hand, the jar cannot vent. When the jar can't vent, pressure within the jar causes the lid to buckle. We suggest you tighten bands comfortably tight to prevent buckled lids.
- Not screwing band tight enough. As above, we suggest you tighten band comfortably tight so rubber sealing compound will be held closely against the top of the jar.
- Insufficient heat to seal the lid such as "open kettle". Do follow recommended processing times and methods.
What will happen if there is loss of liquid? Can I eat the food?Loss of liquid may cause the food to darken, but it does not interfere with the keeping qualities unless the liquid that has been lost has caused food, grease or seeds to lodge under the lid and prevented a seal from forming. If liquid has been lost, do NOT open jar at the end of the processing to replace liquid. Opening the jar will result in spoilage of the food unless you use the contents immediately.
NOTE: Fruit packed raw must have 1 ½ inch of space for syrup - fruit juice cooks out of fruit, and fills jar with liquid. Otherwise too much liquid will boil over and siphoning will cause loss of liquid and possible sealing failures.
As long as the jars remained sealed, they'll be ok, but they should be checked more frequently and used up first!
Should liquid lost from the jar during processing be replaced?
No. Loss of liquid does not cause food to spoil, though the food above the liquid may darken. As long as the jars were processed in the canner for the specified amount of time and they sealed, they should be fine. If, however, the loss is excessive (for example, if at least half of the liquid is lost), refrigerate the jar(s) and use within 2 to 3 days.
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