Canning summer squash properly can keep you from developing food poisoning when the squash is later consumed. Summer squash, like other vegetables, is considered a low acid food. As such, precautions need to be taken to avoid bacteria growth while stored in the canning jar after the process is complete. Use a pressure canner to prepare the recipe and this bacteria won’t have a chance to spoil your finished product.
Sterilize the canning jars by boiling them for 10 minutes. Remove the jars from the water using tongs or leave them sitting in the water until ready for use. You may also boil the rims but do not boil the lids. Lids should be washed in cool water before use.
Prepare the squash per recipe directions. This can be chopped, sliced or diced in large chunks.
Fill the jar with squash allowing for 1/2 inch head space.
Fill the jar with fresh clean water, leaving the required 1/2 inch head space unfilled. Wipe the rims of the jar clean to avoid any debris keeping the jars from sealing properly.
Run the lid under warm water for the best seal possible. Place the lid on the jar then place the rim over the lid and tighten to finger tightness. Finger tight means turning the rims with just your fingers, not applying intense pressure or using tools to tighten.
Fill your pressure canner according to the canner’s instructions. This varies by canner.
Place the filled jars in the canner and place the lid on the canner. Double check to make sure the lid is closed securely.
Place the heat on high and cook per the recipe directions. Adjust for high altitude as needed per recipe directions as well. Once done, turn the heat off and allow the canner to cool completely before attempting to remove the lid. Remove the jars carefully using canning tongs and place on cooling rack to cool.
References and ResourcesCanning Food: How to Can
Canning Basics: Canning Vegetables
ResourcesCanning Basics: Canning Squash
Paul and Bernice Noll's Window on the World : Canning Summer Squash Recipe