I poured the berries into a large pot full of water and began pulling them out one at a time, cutting off the crowns with scissors and placing the berries on drying racks. I employed the time-honored quality-control method of "eating the suspects" (not the disgusting ones, mind you, just the suspects). Most of the suspects I ate tasted delicious, indicating that I was erring on the side of caution in weeding out the berries.
Then I raided my stash of rhubarb, collected in the spring when it was perfect, then cleaned, chopped, frozen, and now ready to co-star in my strawberry/rhubarb jam.
There isn't space here for me to walk you through the whole process, but that's okay, because the wisest thing I could possibly tell you about jamming is that you should simply follow the instructions that come with your pectin.
Pectin? That's a plant fiber commonly found in the cell walls of certain fruits, and it's what gives jam its thickness. Each brand of pectin has the potential to act slightly different, which is why I recommend using the instructions included in whatever pectin you get. You have to be rather anal about following these directions, or it won't work. It may still taste good, mind you, but it won't be jam.
Most pectin requires massive amounts of sugar in order to thicken. This is a bummer for people, like me, who don't like their jam super-sweet, preferring instead to taste the natural sweetness of the fruit or berry they have jammed. I get around this by using "low-methoxyl" pectin, which gels by reacting to a calcium solution that you mix separately and add to the jam. This may sound intimidating and scientific, but it's pretty easy, and it allows you to add as much or as little sugar as tastes right to you. If you shop at a cool store, there should be boxes of the low-methoxyl Pomona's-brand pectin alongside the other kinds. Or you can order it online at pomonapectin.com.
When I jam, I like the berries to be as unaltered as possible. So I don't cut or mash my berries -- making them difficult to measure -- and I cook them as briefly as I think I can get away with. This approach can be problematic when making low-sugar jam, because sugar acts as a preservative as well as a sweetener. Determined, but in need of guidance, I called the telephone number printed on the jamming instructions that came with my Pomona's pectin. The number was called the "JAMLINE."
Alas, it was Saturday, and I could only leave a message. But the berries couldn't wait, so I jammed on. Following the instructions for no-sugar jam, I blended the pectin in hot juice -- frozen apple cider from last year -- and added it to my berries, which I brought barely to a boil. I added lemon juice and a little sugar to taste. When I processed the jars in a water bath, I left them in the boiling water a mere five minutes, conveniently forgetting to add an extra minute for each thousand feet of altitude above sea level that I was jamming at.
The next day as I was eating some of my excellent jam on French toast, the phone rang.
It was Connie Sumberg, the JAMLINE operator and, to my surprise, owner of the company -- which makes her the first company owner who has ever called me on a Sunday to talk about strawberry/rhubarb jam. She spoke with the slow drawl of someone with a lot of common sense, and I desperately wanted her to approve of my unorthodox and undercooked methods.
After listening to my story, she said, "If you see mold in a few months, and the seal on the jar is still good, then you know that live mold spores were sealed inside because you didn't boil it long enough."
Can you just scrape off the mold and eat the rest of the jam?
"That's up to you. It's a personal decision. In the old days that's what they did, because they couldn't afford to throw it away -- unless the whole thing tasted moldy. Then you know the tendrils of mold have permeated the batch."
But, when pressed, Sumberg couldn't recall a single instance of poisoning from undercooked low-sugar strawberry/rhubarb jam. That's good enough for me.