Pressure Canning Butternut Squash

Asked October 5, 2019, 11:03 AM EDT

Hi, I’ve done two batches of butternut squash in my pressure canner. I used 10 lb pressure @ 90 minutes with one inch headspace. When I opened the first batch, the jars were seriously boiling inside and thought they were going to explode. Fortunately they did not but they did lose some water. The second batch I toned down the pressure a little so the thingy on top just rocked very gently and not as much as first batch. When I opened them they were boiling a little, nothing like the first batch though. They did lose water again though. Here are my questions : Do I have to go 90 min with quarts? I was hoping they wouldn’t be cooked so much in the jar as they appear to be and I’m assuming that’s from the time in processing? Also, is it normal to lose water in the jar in processing? Thanks

Kent County Michigan

2 Responses

Hi, sorry for my delayed response - I've been out of town and unfortunately your request did not get re-directed.

According to the science based pressure canning guidelines, you must process quarts for 90 minutes (at 10 or 11 pounds of pressure - depending on which gauge you are using). Is it possible that you were processing it at a higher pressure for the ones that were "really boiling"? It is important to read the manual for your canner to know how your gauge should be "rocking" - the frequency and intensity of it - as they can all be a little different.

You might lose a little water during processing, but there are reasons for losing a large amount, the following was taken from the Fresh (the Ball brand website):

What causes a loss of liquid during processing?

  • Food not heated before canning.
  • Food packed too tightly.
    • Pack food loosely when using the hot pack method.
  • Air bubbles not removed before lids and bands applied.
    • Use a Ball Bubble Freer to release air bubbles and measure headspace.
    • Slide a nonmetallic utensil between food and jar to release trapped air. Repeat 2 to 3 times.
  • Bands applied too loosely.
    • Make bands finger-tight. DO NOT force or use a lid wrench to apply bands.
  • Pressure canner not operating correctly.
    • Continuously regulate heat to maintain consistent pressure. Avoid sudden changes in the heat level.
  • Starchy foods absorb the liquid.
    • Pack all starchy foods loosely.

      If you would like to talk with a Food Safety Educator, you are also welcome to call our food safety hotline at 1-810-285-9565. Thank you.

    Thanks Kara, I think I’m good. I’m fairly new to pressure canning. I didn’t realize that the squash would cook as much in the canner. I think the second batch was better and going to do more soon.