Making Raspberry Jam

All you need to make raspberry jam is half-and-half raspberries and sugar by weight. I have used 3lbs of each, which is manageable. If you notice how much the mass expands while boiling, you will see that you need a very big pot to make more than that, and the bigger the batch, the longer it takes to gel. So here's what you do.

First you must sterilize your snap-lid jars in a canner (the big black pot in these pictures) at a rolling boil for minimum 10 minutes. It can take 30 minutes for one of these babies to reach a full boil. Note that the jars must be completely immersed. I add the lids and my tools on top, in a strainer basket.

Meanwhile, very gently wash the berries and discard any dirt, sticks, bugs or rotten ones. Here, the berries have just been washed:

Heat the berries in a preserving pan, or at least a pot with a thick bottom that distributes heat well. (There are times when I have done it in a cheap enamel pot, but it's riskier because it's so easy to burn the fruit.)

Combine the fruit and sugar off the heat; let the sugar dissolve completely.

Cook at a rolling boil, stirring occasionally and carefully watching out for burning. When the liquid thickens and turns glassy on top, when it runs thickly off your spoon, and when it gels solid if you drop it on a saucer that you've chilled in the freezer, it's ready (5 to 20 minutes, depending on many variables). Skim off any scum on the surface. Don't stir any gel from the edges of the pot back into the pot, and don't put any into your jars.

Use a funnel to fill your sterilized jars (which have been waiting in the covered canner). Leave a little "head room" (air space at the top). Wipe any spilled jam off the rims and lay a lid over each one. Very gently finger-tighten the metal bands, but don't close completely; the expanding jam must be able to expel steam. By the way, it's worth investing in the standard set of tools for this: tongs, a jar-lifter and a funnel, which are available at hardware stores for a modest cost.

Set the jars back into the canner and sterilize again for a minimum five minutes at a rolling boil. When you lift them out, don't tilt. Stand the jars on a dishtowel and don't touch them. You should hear a loud pop from each one as the cooling air inside the jar creates a vacuum and pops the lid tight. When the jars are completely cool, each lid should be sucked inwards. If not, put the jar in the fridge and eat it before it goes bad. Label the others with the date; they will keep for at least a year.

Enjoy!