I love making fruit butter instead of jam. This year I have made apricot butter and pear butter. In the past I have also made plum butter but I don't have a plum tree anymore. Anyway, my question is do you have to be precise on the amount of sugar you use for fruit butters? I know it matters when making jam and using pectin but as far as butters go the ingredients are usually fruit puree, sugar and lemon juice. Then cooking it to a desired consistency before putting it in jars. The recipes I have for these fruit butters use less sugar than jam but I am wondering if I can use even less as they are plenty sweet enough. Do I need all the sugar to help in preserving or is it just a taste and consitency thing?
Sugar is a natural preservative but so is the naturally occurring fructose in fruit and the pectin that is often in fruit as well. I would think if you just made sure that your butters were canned hot so the jars seal, you could give it a try with less sugar. Sealing the air out will cut way down on spoilage. I love experimenting like this in the kitchen and will often sub in Splenda too so it's not so sugary! If all else fails and you're really concerned, freeze your butters until it's time to eat them and I seriously doubt you'll have any issues by adding less sugar.
Hope that helps!
"Come to the cliff, " He said. "We are afraid," they said. "Come to the cliff," He said. They came. He pushed them. And they flew.
Sugar does not change the pH of a solution so you can add as much or as little as you like in your fruit butters.
If you are using a boiling-water canning method for preservation the only real issue to making sure it is done safely is keeping the pH under 4.6. That's why almost all recipes call for citric acid, lemon juice or vinegar which you list as one of your ingredients so you are okay.