I keep a whole cupboard just for saving jars. My idea is to always use whatever comes my way. If someone offers me 30 kilos of plums I will say yes, even if it means three days cooking plums. As right there I'd have pudding in the freezer, crumbles for during winter, jam, plum sauce, pretty jars of these for gift baskets and so on. Using this example as someone did give me 30 kilos of plums last year. We picked lots of apricots of our tree and had 20 kilos or so of nectarines from a neighbours tree.
When making jam the easiest thing in the world is using the microwave. It's a better colour. It looks like gem stones! I use half a lemon (this helps it set) about a kilo of fruit, 3/4 a kilo sugar. I roughly cut fruit taking out seeds, pour over sugar and lemon. Use the largest heavy bowl your microwave will fit. Uncovered. Blast for 10 mins. Stir. Blast another 10 stir. Another 10... then I use my stick blender to break it up more. VERY carefully as a splash would burn badly. I wouldn't even do this with kids around. Another 10 minutes and its done. You can be sure its set point if its coming up and threatening to overflow so keep an eye in the last two sets of ten. You can also take a teaspoon and let it cool. If then you press your finger on it and it holds a dent or print, its set. Another ten minutes wont hurt.
Now and then you get a jam that hasnt set hard. Keep it in the fridge and use it on pancakes as sauce! Properly set jam sealed immediately in spotlessly cleaned jars will keep a couple of years.
I wash all my jars well and lay them in a cold oven. You turn the oven on and heat it up then turn it off. When cool these jars are sterilised. If you do this your jam will keep.
The thing is you always need to have plenty of jars on hand. Thrift shops sell them very cheaply and I buy cellophane toppers in the supermarket, also very inexpensive. Sometimes drinking glasses are an idea, small pretty ones are great for jam.
Bottles are easy to save. Lots of wine or spirit bottles are beautiful quality thick glass. If the labels are soaked off they are lovely for flavoured vinegar or olive oil, dressings and sauces, even homemade bubble bath or hand wash.
So in my mind a cupboard full of jars leads to all sorts of good things.
Im getting ready now. The apricots are green little balls... it won't be long. And if anyone says would you like some fruit I'll say yes please. And if I see amazing specials I'll grab those too. Last year I got cherries and strawberries very cheaply as they were going soft. They made the most beautiful jam that looks like rubies!
This is some apricot from last year...