Esthetics. Looks prettier without. Sometimes though, especially if fruit was cooked with skins, removing the foam also takes off some of the floating non-soluble bacteria (so I was told). I usually let the cooked mixtures cool off the burner for about 5 minutes. By then a lot of the foam bubbles have popped. Stir it a little and more will disappear and then fill the jars. The mixture will still be hot enough to process.

Nancy is right, it's just prettier without the foam. I usually put the foam into a small bowl and the kids eat it!

If you let it cool off heat like Nancy suggests it can also help to distribute the fruit more evenly through the preserves, and that prevents fruit from floating to the top when processing too.

those preserves sure are good, aren't they?

Annie

"non-soluble bacteria" I've never heard that bacteria dissolve, like salt or something?

Annie: I only made a small batch to see if I liked them. After tasting I remembered that I had made them before and like them a lot. I'm seriously thinking about going to the store to get the 4# of pears and making more because my one pint jar of preserves isn't going to even make it to T'day.

And, thanks for the answers to my question! I kinda wondered if it might not be for looks.

Kate, a pint wouldn't last long at my house either, they're my favorite. Fortunately my husband prefers tomato marmalade, so they are all mine!

I'm always happy to help a fellow canner if I am able to, so you are very welcome.

Happy canning!

Annie