Indeed, it’s weird. Like other “questionable” methods listed in Anne-Marie Desbiens’ book (the hot blanket, the slow cooker, the dishwasher, etc.), the microwave is not recommended, “among other things because the microwave oven does not heat evenly. Areas overheat, but the core of foods – like small beets, for example – don’t reach temperatures hot enough. It may therefore be insufficient to kill all the micro-organisms. Also, heat transfer is less efficient in the microwave than it is when using a moist heat source.”

“It doesn’t matter what you make – jam, marinade, etc. —, all canned goods should always be heat treated after potting. I think the most glaring mistake many people make is not treating the pots. We simply preheat the jars, boil the jam, put that in the jar, close and sometimes even invert the jar (which is not recommended either). And when you hear the “pop” sound, you feel like it worked. But this sound does not mean that we have sterilized the food and destroyed the microorganisms, it simply means that we have created a vacuum! When we put our acid preserves in a water bath, they are better, more nutritional, they seal better, keep longer and are safer. »

“There are several reasons why jars may not seal. First, you must leave an empty space in the jar, of a different height depending on the food you are canning. In general, the more oxygen the food has inside, the more space you need to leave. If there is not enough space, the liquid will tend to want to escape, because there is too much oxygen. Sometimes also, the jars do not seal because the disc was tightened too hard or not hard enough. Finally, it can also be linked to insufficient heat treatment or a poorly cleaned neck. »

“It’s the same rule as for all foods, canned or not: in general, the more liquid a food is, the more it is not recommended to eat it when there is mold on the surface. If we have a piece of parmesan that has mold, we remove an inch and we can eat it. But when the food is liquid, like yogurt or canned food, if the mold creates toxins and these toxins migrate into the liquid, removing the top is not enough. There could be toxins out there. It is therefore advisable to throw it away. In addition, if there is mold, it is a sign that the can has not been properly treated. »

“I hear that phrase often. There are many people who have bought an autoclave, but have never used it, because it scares them. It’s understandable – it’s still a machine under pressure – but it shouldn’t scare us. All modern autoclaves today are equipped with two safety systems that are activated if the pressure ever becomes too high. This fear is probably also caused by the lack of resources. When you buy an All American autoclave, for example, the entire manual is in English, and it’s not clearly explained. »

“I hear that very often too! People feel bad, because every year they throw away their aunt’s pickles or their friend’s ketchup. They are afraid and don’t want to take risks. I understand them: I don’t eat any canned food that’s given to me. As seen in my book, there are many things to consider when canning to ensure that it is truly safe and safe. But hey, if I were certain that the person was following the recommendations of the United States Department of Agriculture – the same ones that I share in the book – I would be reassured. When you follow a good recipe validated in the laboratory, it is very safe. »

In Anne-Marie Desbiens’ book, in bookstores since September 6, the first part is devoted to the fascinating history of the invention of canning.