Jams processed in a dishwasher

Asked June 23, 2013, 2:09 PM EDT

My daughter told me she and her girl friends made strawberry jam they processed in a dishwasher rather than in a boiling water bath. Sounds dangerous to me. What is your opinion? Thank you.

Clackamas County Oregon home food preservation

1 Response

OSU Extension does not recommend using a dishwasher for processing jam. Jars processed in dry heat can explode and send broken glass covered with jam all over the place! Additionally, the heat penetration will be uneven and insufficient. These jars need to be brought up to boiling water temperature, 212 degrees F at sea level. Most dishwashers don't get above 165 degrees F.

For jams, a boiling water bath canner* should be used. Jams need to be fully submerged in water during processing to expell the oxygen that could help produce mold if left unprocessed.

To prevent spoilage from mold in the jam that they made, the girls can store the jam in the refrigerator for use in the near future or freeze it. If they choose to freeze the jam, be sure to open it and increase the head space by about 1/2" before it goes in the freezer. This way, the jar doesn't break from the expanding jam. The jar lids should be a little loose so air can get out while it is freezing. Tighten the jar lids after the jam has frozen.

*Home canners living on a buget can make their own water bath canners from an existing tall cooking pot, a metal tray that elevates the jars off of the bottom of the pot for good water circulation and heat penetration and a tight-fitting lid. The cooking pot needs to be able to hold water that will measure 1 to 2 inches above the tallest jar while the water is boiling. The metal tray could be from the bottom of a pressure canner (sold separately at stores that sell canning supplies or on-line), possibly a round cake cooling rack, the rack from a pressure cooker, or make a trivet of canning jar rings held together with twist-y ties.

There is no substitute equipment for a pressure canner.

You can send them this link for their future projects! http://extension.oregonstate.edu/community/food-preservation