By Jenny McCoy—Chef Instructor, School of Pastry & Baking Arts
As the summer nears its end, tables at the greenmarket abound with gorgeous fruits and veggies—produce that will be sadly missed in just a few months time. Yet in the modern kitchen, an age-old cooking technique exists to keep enjoying those summery ingredients during chillier months—preservation.
For ages, humans have applied a variety of methods to preserve food, through drying, curing, fermentation, pickling and salting. But in 18th century France, Nicolas Appert, a maverick chef, began researching how to preserve foods in a new way, one that would maintain foods closer to their original fresh state. Initially, he believed that removing the presence of air from stored foods would help them last longer. Though a lesser amount of air can aid the preservation process, he wasn’t quite right. Inspired by a contest organized by Napoleon as a means for feeding the military, Appert continued his food preservation experimentation. Eventually, he found a heating process that could allow foods to remain unspoiled for long lengths of time. A decade and a half of his research resulted in a method we still use today: glass jars filled with foods, then corked and sealed with wax. The jars are then boiled until hot enough to kill microbes that cause food to rapidly spoil, pasteurizing their contents.
Keep reading to get Chef Jenny's tips for canning plus a recipe for blueberry-thyme jam.