I love making jam. Fruit, water, sugar, and maybe a little lemon thyme or rosemary to pique the taste-buds while they savour a little toast and jam brekkie. Since I tend to have a problem with restraint at the farmer's market, bringing home four pounds of apricots when one would have done just nicely for after dinner treats and lunches, a love of jam making is a good thing. I made the first batch of the season yesterday, in fact, using David Lebovitz's easy to follow instructions. It's not hard to make jam, you just need to keep an eye on it so it doesn't burn, and you can't get impatient and take it off the heat to early or it won't gel.
What I am not a fan of is canning. This is the process of making sure that all the air and micro-organisms are out of the jars so that you can put the jars on a shelf in your pantry and not be afraid of contracting botulism with your breakfast 6 months down the road. It isn't hard, it's just hot and sweaty work, involving giant vats of boiling water and a hyper aware, operating room level of cleanliness (boiling and sterilizing all tools, etc). The good news is that sugar is a great preservative, and if you are able to give your jam real estate in the refrigerator, you can keep it there for at least six months (if it lasts that long!).
But what about back in Mrs. Black's day, when your average house keeper didn't have a fridge? She is an ardent believer in the ability of sugar to block spoilage, but still recommends putting a lid on it - albiet one of paper...
"As this is the season for making preserves, it may be useful to young housekeepers to tell them what I consider the best way of covering jelly. First of all make a little common paste, then have the papers cut the size necessary, and the names written upon them. Proceed to put the paste over the inside of the paper near the edge. Do all this while the preserve is boiling; then fill a can and instantly put the paper on, sticking it securely all round, and so on till all are finished. With a damp cloth wipe the outside of the cans, and they are ready for storing in a dry place. Unless you put the paper on the very moment the jam is put into the jar you must allow it to get quite cold. This will be found an effectual plan to prevent mouldiness, if the preserves are properly boiled with enough sugar."
I am assuming that "common paste" is just a little flour and water combination mixed together based on the recipes I found here. So, a little paper label glued in with some flour paste to keep out the flies and "mouldiness." Blurg. I suppose it did an admirable job, but I'm just happy we've worked out better ways of keeping bacteria at bay.
In the meantime, I'll be enjoying my mould free apricot jam on toast!