Strawberry-Balsamic Jam

photo: Eric Diesel

I remember August as the most relentlessly hot month in the sun belt, but in the northeast, we are experiencing our first cold snap. August juxtaposes sunny days with cool ones -- nothing drastic, just a few days of damp chill that allow for open windows rather than air conditioning. Today on the subway platform many of us were wearing light sweaters, and I believe I detected a couple of the first new fall suits. It’s a reminder of the transitional nature of August – though it’s the month of the last days at the pool, the last week at the beach, it is also the month that the back to school supplies appear in the stores.

As we’ve been celebrating all month, August is also the month of the first harvest, when the plants that reached maturity during the high point of summer now bear fruit and vegetables and grains. I’ve been canning every weekend. The tally so far: dill pickles, giardiniera, fennel relish, chili sauce, candied citrus, brandied cherries, and blackberry jam. Still to go: pear-cranberry jam, lemon jelly, pickled jalapenos, and my grandmother’s chow-chow and lemon-dill pickles.

The definitive expression of summertime canning is strawberry jam, for the taste of a fresh strawberry is the taste of summer itself: bracingly sweet but fleeting. We don’t get the right kind of light in our urban home for a strawberry pot, but, starting late spring, we get plump, plush berries from as close as New Jersey and as far as California. Just recently, I’ve noticed that the supply is dwindling while the price is rising, which tells me that the season for strawberries is drawing to its sad, inevitable close.

photo: Eric Diesel

Luckily, we captured ten jars of summer sweetness from when the berries were at their lush-est. At the suggestion of an Italian friend, we replaced the lemon juice typically used when preserving such low-acid fruit as strawberries with balsamic vinegar. It is necessary to introduce an acid or the sugars will crystallize. The results were spectacular. The vinegar adds a caramel note to the jam, underscoring the sweetness of the berries the way a bass note underscores the sopranos in a boy’s choir. This jam will be perfect for leisurely weekend brunches and rushed weekday breakfasts.

Here is an easy, rewarding recipe for strawberry-balsamic preserves. As with all canning processes, it looks like a lot of steps, but it goes quickly once you get your rhythm going. Be sure to follow safe canning procedure – I’ve included two good links. As you make the jam, you may find, as I do, that the process of canning is as much a celebration of the transitory nature of these August days as the jam itself is.

STRAWBERRY-BALSAMIC JAM

A bottle of good balsamic vinegar is a worthwhile investment for your pantry; here’s one I like. It is best to over-estimate the number of berries to obtain for making jam; set aside those you don’t discard or use for the jam to make fruit salad.  Remember: it is crucial to follow safe preparation, canning and storage procedures.

2 -3 flats strawberries
1 1.75 ounce box fruit pectin for canning
¼ cup balsamic vinegar
1 vanilla bean
7 cups white sugar

1. Prepare canner, jars and lids. For instructions on safe canning, click here: http://www.uga.edu/nchfp/publications/publications_usda.html, or here: http://www.freshpreserving.com/getting-started.aspx

2. Set an in-sink colander in place. Place the strawberries in the colander and rinse well under cool water. Place a small sharp knife, a cutting board and a large bowl near the sink. Place a large stock pot on the stovetop.

3. Pick through the strawberries, discarding any that evidence mold or soft brown or black spots.

4. Place a strawberry on its side on the cutting board. Use the knife to cut a circle under the leaf. Pull out the leaf, taking the internal hull with it, and discard. Use the knife to cut away and discard any unripened white or yellow flesh. Turn the strawberry cut-side down and cut downwards to halve the strawberry. For large berries, halve the halves to form quarters. Scrape the cut strawberries into the bowl.

5. As the bowl starts to fill, use a potato masher to lightly mash the berries. You just want to express the juice; it is desirable for some large pieces of berry to remain. Use a glass measuring cup to measure out two cups of mashed berries; place mashed berries into the stock pot. Continue hulling, cutting, mashing and measuring berries until the pot contains 6 cups of mashed berries.

6. Measure the full amount of white sugar into a large bowl and set the bowl near the cooking pot.

7. If necessary, wipe down the cutting board and rinse the knife. Lay the vanilla bean lengthways on the cutting board and use the knife to slice the vanilla bean lengthways into two long strips.

8. Working carefully to protect the vanilla bean seeds, hold each half over the bowl of sugar. Carefully scrape the knife down the inside of the bean so that the tiny seeds fall into the sugar. They will also stick to the knife; swirl the knife in the sugar to release those seeds into the sugar. Place the scraped vanilla bean into a glass jar for future use as an infusing agent.

9. Turn the heat under the cooking pot to medium-high. Use a heavy wire whisk to stir the berries. They should start bubbling and expressing more liquid. Stir constantly, turning down the heat if the mixture starts to steam too much, until the mixture reaches a full rolling boil that cannot be stirred down, approximately three minutes.

10. Once the berry mixture reaches a full roiling boil that cannot be stirred down, add the balsamic vinegar. The mixture may flare so step back before adding the vinegar; be prepared to lower the heat if the mixture flares. Use the wire whisk to incorporate the vinegar into the berry mixture; one or two stirs of the whisk should suffice.

11. Empty the envelope of pectin into the berry mixture. Use the wire whisk to incorporate the pectin into the berry-vinegar mixture; two to three stirs of the whisk should suffice.

12. Add the sugar all at once to the berry mixture. Use the wire whisk to incorporate the vanilla sugar into the berry-vinegar mixture, stirring well to dissolve the sugar. Readjust heat to medium-high and cook, whisking constantly, until mixture reaches a full rolling boil that cannot be stirred down.

13. Once mixture reaches full rolling boil that cannot be stirred down, use a slotted spoon or skimmer to skim foam off of jam and into the bowl that contained the sugar. Turn off the heat.

14. Place a clean towel on a counter near the canner.

15. Use canning tongs to remove hot jars from water bath. Do your best not to touch the hot jars; let the tongs do the work. Place hot jars mouth up on the clean towel.

16. Wrap a clean tea towel around a hot jar, being careful not to let the towel touch the rim of the jar. Use the towel to transport the jar to the pan containing the hot jam. Place a clean canning funnel into the mouth of the jar. Use a clean spoon or ladle to fill the jar with jam to the ½-inch mark. Continue until all of the jars are filled. It is okay if there is jam left over; refrigerate it for use within 1 month.

17. Check for and remove air bubbles if any (see instructions).

18. Use a clean, damp sponge to wipe the rim of each jar. Center a clean, hot lid (see instructions) on each jar. Screw a band down on each jar until it meets resistance; increase just until tight.

19. Use canning tongs to return the jars to the boiling water bath. Add more water if necessary to ensure that the jars are completely covered by boiling water by 1 inch. Process in boiling water bath for 10 minutes.

20. After jars have processed for ten minutes in the boiling water bath, turn off the heat. Remove the canner lid and set aside. Let jars sit in hot water ten minutes.

21. After ten minutes, use the canning tongs to remove the jars. Being very careful of the hot jars, lids and liquid, place jars upright on the towel. Allow to sit 24 hours. After 24 hours, check for a vacuum seal (see instructions). Label each jar with the contents and the date prepared. Safely prepared, stored and sealed, the jam will keep for one year from date of preparation.