In a large preserving pan, combine the raspberries, granulated sugar, and lemon juice. Place the pan over low heat, stirring occasionally, until the sugar has completely dissolved. You can check by running a wooden spoon along the bottom to feel for any remaining crystals.

Increase the heat and bring the mixture to a rolling boil. Boil for approximately 7 minutes, then remove the pan from the heat. Drop a small amount of jam onto a chilled saucer, then place the saucer in the refrigerator for about a minute.

To test if the jam has set, run your finger through the chilled jam. If it wrinkles and holds a gel-like consistency, it’s ready to jar. If it hasn’t reached the desired consistency, return the pan to a rolling boil for 2-minute intervals, testing each time until set (usually around 9 minutes).

Using a small ladle, pour the jam into sterilized jars, filling them to the top. Seal with lids immediately to preserve freshness. This recipe makes approximately 2 jars (900 ml in total). Store in a cool, dark place, and refrigerate once opened.