- 1L (4 cups) granulated sugar
- 1L (4 cups) raspberries
- Warm sugar in an ovenproof shallow pan at 250°F/120°C for 15 minutes.
- Place berries in a large stainless steel saucepan. Bring to full boil over high heat, mashing berries as they heat. Boil hard for about a minute, stirring constantly.
- Add warm sugar, return to a boil and boil until mixture forms a gel, about 5 minutes. See notes for an easy gel test.
- Ladle into sterilized jars and process for 5 minutes in a canning bath.
Dip a cool metal spoon into the hot fruit. Immediately lift it out and away from the steam and turn it horizontal.
At the beginning of the cooking process, the liquid will drip off in light, syrupy drops. In a minute or two, the drops will be heavier. When the drops are very thick and the two run together before falling off the spoon, the jam is done.