When in doubt, follow the recipe's guidelines. But if it doesn't specify, I always go with ten minutes for half-pints and 15 for pints, and then you don't have to sterilize the jars ahead of time.

Hope that helps--Gina

Here is a link that might be useful: Lindsey's Luscious (my food blog)

Normally jelly recipes say 5 min. That is because they are more delicate and it could be possible to break the gel if you process longer. Jams are done at 10 min. most of the time. I just skip the boiling of the jars and process all types for the 10 min. I don't have any problem with doing that. Most people I know process for the 10 min.
Any food needing 10 min. or longer just need clean, hot jars, not boiled for sterilization.
If your recipe says use half pints, then use them. Most jams and jellies say half pints because using pints or larger can cause them to not gel due to not the same amount of heat to the insides of a jar that size. This is why you don't see quarts listed for jams. It would cause more failures of the gel because it would require a longer processing time.

Pomona breaks all those rules about jar size, and breaking the gel. I made a quart of blueberry preserves with Splenda and Pomona pectin and it set up very well.

Thanks!

I used 1/2 pints and processed for 10 min. The thing is, I couldn't find anywhere in the sure-jell instructions that specified the size jars.

Oh, and the jam turned out pretty yummy. :)

Connie

Troublemaker, I think its defined in the end product quantity. Something like 5 eight ounce jars..

ksrogers said "I made a quart of blueberry preserves"... you can preserves in quart jars? I tried pints and found they took forever to gell. Do you go through that much blueberry preserve that fast you have to can it in quarts? Or are you like me...ran out of 1/2 pints?

Ok, I think I'm just making myself crazy(er). In the chart thingy it says it makes 8 cups, but doesn't specify jar size. (The freezer jam instructions do) Was hoping to use pints instead of halfs - I'm going through them like mad and I only made 2 batches of strawberriy. Ok, well on to cherry jam (and to Winco for more 1/2 pint jars).

Thanks again :)

Connie

A cup is an 8 ounce jelly jar, and it is assumed that your using stardard 8 ounce jelly jars. The quart of blueberry was just one jar, and I used the Pomona pectin as it was actually setting up on the ladle and the canning funnel while it ws being poured in. IUt set perfectly and was given to somone who love anything with blueberries, and it was done without sugar, so that was the biggest issue. I used a ffew dried blueberries along with the ones off my bushes and some that my dad had picked and frozen a long time ago. The quart of blueberry ws the one and only time I did that, and it was gone in less than a week.