1. Macerate the berries
Place the mixed berries and sugar directly into a large pot or Dutch oven. Stir gently to combine and let sit for 30–60 minutes, allowing the berries to soften and release their juices.

Chef’s Tip: If using frozen berries, this step helps them defrost and start breaking down naturally—no need to thaw completely first.

2. Start the jam
Place the pot over medium-high heat and bring the mixture to a gentle boil, stirring occasionally as the sugar dissolves.

3. Simmer and reduce
Once boiling, reduce the heat to low and simmer for 40–50 minutes, stirring occasionally, until the fruit breaks down and the mixture thickens.

Chef’s Tip: Stir more frequently towards the end of cooking—this is when the jam can catch and burn on the bottom.

4. Skim if needed
As the jam cooks, skim off any foam from the surface using a slotted spoon.

Chef’s Tip: Don’t worry about removing every bit—just the thicker foam. This keeps your jam clear and glossy.

5. Check for setting point
The jam is ready when it reaches 104°C (220°F) or when it coats the back of a spoon and slowly drips off.

Chef’s Tip: No thermometer? Use the chilled plate test. Place two small plates in the freezer before you start cooking. When you think the jam is ready, spoon a little onto the cold plate and let it cool for 1 minute. Gently push it with your finger—if the surface wrinkles and holds its shape, the jam is set. If it’s still runny, continue simmering for a few more minutes and test again.

6. Finish the jam
Stir in the lemon juice and vanilla extract (if using). Remove from heat and let the jam cool for 5–10 minutes.

7. Jar and cool
Spoon the jam into warm, sterilized jars, leaving about 0.5 cm (¼ inch) headspace. Seal and allow to cool completely.