Strawberry Rhubarb Confiture

Preparation

1. Step 1

   In a large nonreactive bowl, combine the strawberries, rhubarb, sugar and lemon juice. Split the vanilla bean lengthwise and scrape out the pulp. Add the pulp and bean to the bowl. Mix gently but thoroughly. Cover, refrigerate and allow fruit to macerate 6 to 12 hours.

2. Step 2

   Fit a large pot with a rack or line it with a folded kitchen towel. Fill with water and bring to a boil. Sterilize 6 half-pint canning jars by running them through a dishwasher cycle. If boiling them, add jars to the pot and boil for 10 minutes. The jars may be left in the dishwasher or pot until ready to be filled.

3. Step 3

   Strain the liquid out of the berry mixture into a heavy-bottomed large pot. Allow liquid to drain for a few minutes, pressing on the fruit. Set the fruit aside. Place the pot over medium-low heat and slowly bring the syrup to 220 degrees Fahrenheit on a candy thermometer, a strong boil that won't stir down. If your pan is broad and the syrup is not very deep, tilt the pan frequently and place the candy thermometer deep into the syrup, to measure the temperature more effectively. This could take about 45 minutes. Stir frequently.

4. Step 4

   Place the canning rings in a small saucepan, cover with water and bring to a boil. Turn off the heat and add the lids to soften the rubber gaskets.

5. Step 5

   Remove the vanilla bean from the fruit and stir the fruit into the syrup. The boiling will slow, but will come back quickly. Watch the bubbles in the boil as you stir. Foam will form because the water in the fruit is drawn out, to be replaced with the syrup. In about 10 minutes, when the confiture is almost ready, the foam will begin to dissipate, the bubbles breaking more slowly and exposing a clear syrup below.

6. Step 6

   Turn off the heat. Let the bubbling stop. The fruit should have absorbed the syrup and be suspended through the jam. If the fruit is floating, return it to the heat for another 2 minutes of boiling.

7. Step 7

   Some foam may remain in the syrup; add the butter and stir to dispel the last of the bubbles. Ladle the hot preserves into the warm jars, leaving ¼ inch at the top, just below the first ring on the jar's neck. Wipe the rims of the jars clean with a damp towel. Place the lids, rubber gasket down, facing the glass rim; tighten the rings, and lower the jars into the stockpot of boiling water. Return to a full boil and boil the jars for 10 minutes. (This is called processing.)

8. Step 8

   Transfer the jars to a folded towel to cool for several hours; you should hear them making a pinging sound as they seal.

9. Step 9

   Test the seals by removing the rings and lifting the jars by the flat lid. If the lid releases, the seal has not formed. Unsealed jars should be refrigerated and used within a month or reprocessed. Rings and the jars may be reused, but a new flat lid must be used each time jars are processed. Reheat preserves to the boiling point, then continue as before. And relax: If your preserves are on the runny side, just call them syrup and serve warm over pancakes.