Editor’s note: The original, vintage recipe does not contain directions for jar size or for water bath processing times. We’ve added those in .
To make twelve small jars [1/2 pints]:
8 cups fresh raspberries, washed
8 cups sugar
In a large pot, break apart and mash the raspberries with a wooden spoon and/or potato masher until there are no large pieces left. Constantly stirring, place the pot over heat until bubbles form when you are not stirring and cook for 15 minutes. Add the sugar in small increments, and when all sugar is added, allow the jam to bubble again and cook for another 30 minutes, constantly stirring to avoid the jam scorching. Skim the foam “well after the sugar is added, or the jam will not be clear” (or so says Mrs Beeton). Spoon into [sterilized] jars and put the lids on.
[Process in a water bath canner for 5 minutes.]