Have you ever heard of Weck? They originated in Germany, and make the proshest canning jars. The sealing mechanism is a little different from the Ball jars that you usually see; The lid and jar are made of glass, and there is a non-reusable rubber ring that fits between the two. You fill the jar up as usual, and use a pair of clamps to hold the lid onto the jar while the cans are processed. The jars must cool completely, and then you can remove the clamps. If a vacuum formed, you should be able to pick up the jar by the lid alone. The tongue of the rubber gasket should point down a little, too. To remove the lid, you just pull on the tongue. You should hear a little psssst sound as the vacuum is broken. More detailed instructions are available on their website, along with order information.
We took advantage of the break in the heat wave last weekend and went strawberry picking. It was a perfect day for picking - overcast and the temperature was just right!
This year, we held back and only picked 10 lbs! It made about 12 8oz jars of jam. I decided to tweak last year's recipe; this time, I made two batches. I substituted a combination of 1 tbsp lemon juice/2 tbsp balsalmic vinegar for the straight lemon juice of the original.
I added 6 mint leaves and 10 grinds of black pepper to the second batch near the end of the cooking time, removing the mint leaves before I ladled the jam into the jars (inspired by Chocolate & Zucchini's recipe).
The balsalmic strawberry jam added a deeper flavor to the jam. The mint and pepper can only just be tasted, and lend a fresh and midly spicy taste to the jam. It's really very good - don't let the mint scare you away!
3 lb. ripe strawberries (4 1/2 pints), rinsed and hulled
Special equipment: eight or nine 8-oz canning jars with lids, funnel, clamp or tongs
To wash the berries, gently scoop them into a sink filled with water. Swish them around a little, and let them sit for a while. The dirt should fall to the bottom of the sink.
Hull and quarter the berries. Put them in a deep pot made of non-reactive material (stainless steel works well). Make sure that there is enough room in your pot! If there is less than 5" between your berries and the top of your pot, you might have a rather anxious time of it. When the jam boils, lots of air bubbles are trapped in the dense liquid, which will begin to rise very quickly.Pour on the sugar and lemon juice, and mix well with a wooden spoon. Cover the pot and let the berries macerate for about two hours. If you like your jam smoother, you can mash them with a potato masher instead.
While the berries macerate, wash your jars and set them in the oven. They should be in there for at least half an hour. Wash the lids and rings, and set the rings aside. Put the lids in a pot of boiling water to sterilize them, and to make the rubber around the edges a little more pliable.
Bring the pot of strawberries to a full boil (you need to boil off the liquid to achieve a jammy consistency). Make sure to stir often (with your wooden spoon) and skim off any foam from the surface. The foam will make your jam cloudy if it's left in the pot, although you can eat it separately.
After half an hour of boiling, your jam should be just about ready. Don't boil the jam for more than 40 minutes, however, otherwise the pectin in the fruit will break down and the jam will turn dark.You can test the consistency of the jam by chilling a plate in your freezer. Spoon a little bit of jam onto the plate, and check the thickness of the jam once it has cooled.
Take a jar out of the oven and ladle the jam in until within 1/4" of the rim. Wipe any jam off the rim with a damp towel, and use tongs to take a lid out of your pot of boiling water and put it on the jar. Quickly screw a ring over the lid (it has to be tight enough to hold the lid onto the jar). Repeat this process until you fill up all of your jars.
Put the jars into a deep pot filled with boiling water; make sure the water reaches above the rim of the jar lids. Cover, and let the jars boil for ten minutes. Remove the jars with tongs and let them cool on the counter. The lids should begin to pop within minutes. If you have any lids that didn't seal, throw them out or eat immediately.