First, you need to pick your berries. This may take some time, but it will be worth it in the end. Make sure to choose ripe berries that are free of stems or leaves.

In a separate bowl, combine the sugar with xanthan gum. If you are using freshly squeezed lemon juice, add it to the bowl as well. Set aside for later use.

Rinse the berries under running water to remove any dirt or debris. Remove any stems or leaves that may still be attached.

Using a food processor or meat grinder, crush the berries until they are liquefied. This will create a smooth texture for your jam.

Transfer the liquefied currants into a large pot. If you have a large quantity of berries, you may need to use multiple pots.

Add the sugar mixture to the pots with the crushed currants. Stir well and make sure that the sugar dissolves completely.

Now place the pots on the burner and set the temperature to high. Stir continuously until the sugar is fully dissolved and the berries release their juice. This should take about ten minutes.

As the mixture heats up, you will notice it start to foam. To prevent overflowing, only fill the pots halfway with crushed currants initially. Stir the mixture every minute or so to prevent ingredients from settling at the bottom and burning.

Once the jam starts to bubble, reduce the heat to low/medium and let it simmer for about 15 minutes. Stir occasionally to prevent the jam from settling at the bottom and burning.

While the jam is simmering, wash the canning jars and lids with soap and warm water. Place them on an oven rack, including the lids. Preheat the oven to 250°F and let the jars and lids sterilize for the entire time the jam is simmering.

After the simmering time is up, turn off the heat on the jam. Using kitchen gloves, carefully remove one jar and lid at a time from the oven. Place canning rings over the jars to keep the mouth of the jar clean.

Using a large serving spoon or scoop, fill the jars with the jam, leaving a ½-inch headspace at the top. This will allow room for expansion during storage.

Remove the canning ring, place a flat lid on top of each jar, and reattach the canning ring tightly. Set the jars aside to cool completely before storing.

Once the jam has cooled, it will have a thick consistency. Store the jars in a cool, dark place until ready to use. Enjoy your homemade blackcurrant jam!