The way I've written the recipe, this is a rather low-sugar jam. I used 1/2 the weight of the berries in sugar. I had 2 pounds of berries, so I used 1 pound of sugar. You can also use a higher proportion of sugar and most likely end up with a jam that sets with less cooking and also one that will keep longer under refrigeration. You can use 3/4 of the weight of the berries in sugar or even 1:1, so for 2 pounds of fruit, you'd use 2 pounds of sugar. For my money, my jam was plenty sweet enough and has a ton of berry flavor.