If you mention the topic of oven canning, prepare to get an earful of advice against trying the technique. Warnings include: Your jars will blow up! You’ll get botulism! It’s old-fashioned! To which we reply, really?
We’re big fans of oven canning–Alexa swears by it, in fact, after taking a class at Blue Chair Fruit Company–if you’re making jam with fruit that has high sugar levels to prevent the growth of bacteria. Alexa has oven-canned batches of blueberry, strawberry, plum and apricot jams, as well as blood orange marmalade:
Above: The basic technique for oven canning: While preparing the fruit mixture on the stovetop, sterilize jars in the oven at a low temperature for 30 minutes. Pour fruit mixture into jars, and return them to the oven for 15 minutes. For step-by-step instructions, see Shutterbean.
Above: There are caveats. For instance, your oven should heat evenly to ensure all the jam is finished at a consistent temperature. Image via Shutterbean.
Above: Ms. Saunders leading a Jam Making 101 class in Oakland, CA. Photograph by Blue Chair Fruit Co., via Flickr.