Steralize and dry a glass jar having a lid (min 500mili litres capacity) and allow it to dry

Wash and blend the berries into a smooth liquid using a blender.

Keep sugar and fresh lemon juice ready to use before you start.

Seive the berry mix into a non stick heavy based cooking pot to get rid of seeds, if any.(if you can get rid of tiny seeds on strawberries, blackberries before blending or comfortable with the seeds in the jam, you can avoid this step)

Add the sugar and lemon juice into the mix and keep cooking on medium flame. You can stir occasionally. (The mix will splutter as it heats up)

Keep cooking till you see the mix thicken and check with a steel spoon. If it's runny/liquidy, you need to continue cooking.

Once the desired thickness has reached, turn off the heat

Ideally this jam can stay out, but storing in a refrigerator is optional.

This jam can stay good for 6 months and beyond.

Tip:the quantity of sugar depends on you

Tip: the jam ideally thickens within 20-25mins on medium-low flame.Depends on the vessel used, you may need more or less time too