Wash the figs and dry them.

Remove the stems and cut them into halves, quarters, or small pieces depending on the consistency you want for your jam.

In a bowl, mix the figs with the sugar and lemon juice. Cover with plastic wrap.

Let macerate for 2 to 4 hours at room temperature or overnight in the refrigerator.

Sterilize the jars and their lids by placing them in a large pot and covering with water. Bring to a boil and count 15 minutes from the start of boiling.

Turn them upside down on a towel and let them air dry.

Once the figs and sugar have macerated, pour them into a large pot and bring to a vigorous boil.

Add the tablespoon of butter (optional) and stir well.

Cook for 10 to 15 minutes from the start of boiling, stirring occasionally to prevent the jam from sticking to the bottom.

The jam should be translucent and shiny.

If you want a smooth jam, crush well with a slotted spoon or blend it.

Check the consistency by pouring a bit of jam onto a frozen plate. The jam should set and not run.

If you have a sugar thermometer, remove the jam from the heat at 105°C (221°F).

Fill the jars with the hot jam using a funnel, leaving 0.5 cm (0.2 in) from the top.

Close with the lids, ensuring they are tightly sealed.

Immediately turn the jars upside down on a towel.

Let the jars cool completely upside down.

Turn them right side up and store in a cool, dry place away from light.