Kumquats are delightful little citrus fruits with sweet skins and tart flesh. Here in the Bay Area you can buy kumquats at Trader Joe's or at the farmer's market, depending on the time of year. Kumquat skins contain pectin, a natural thickener, which adds body to the tangy syrup.
I'm from Vermont so happen to have Bragg's Farm Maple Sugar in my pantry, but white or brown sugar will work well, too, and you could try adding a shot of maple syrup to your cooking liquid to give it a maple-y depth of flavor, if you're inclined. I haven't tried them, but am certain that agave sweetener or honey would work beautifully, as well, though you might have to adjust the cooking time.
I have used white, red wine, and apple cider vinegar with good results. I'm sure white or champagne vinegars would also be great. Red wine and apple cider vinegars will result in pickles with a darker, almost amber color.
I love the savory warmth and flecks of color that red pepper flakes and black peppercorns add to these pickles. Other possibilities are vanilla bean, pink peppercorns, anise seed, or grated fresh or sliced candied ginger.
Step 1: Gather Your Ingredients
• 340 g (12 oz) of kumquats
• 1/2 cup of sugar (maple, white, or brown sugar)
• 1 cup of vinegar (apple cider vinegar, red wine vinegar, or white)
• 1 teaspoon of salt
• 6 - 8 peppercorns
• 1 tablespoon of red pepper flakes (use only 1 or 2 teaspoons for a less spicy pickle)
Step 2: Prepare the Fruit
Slice kumquats in half lengthwise, and carefully pick out the seeds with the tip of your knife.
Step 3: Cook the Kumquats
Bring the pot to a boil over medium heat. Reduce heat slightly and simmer for 15 minutes, at which point the fruit should be starting to get tender. Give it a stir occasionally, so the ones close to the bottom of the pot don't get more cooked than the ones at the top.
Step 4: Season and Reduce
Let cook for about 15 minutes more, stirring occasionally. The objective here is to continue to soften the fruit, to combine all of the flavors well, and to cook off as much water as possible, until you have a nice light syrup.
Taste your pickles and adjust the flavors to your liking by adding more seasonings, sweetener, or vinegar. Let them cool down and put them in the fridge overnight.
Step 5: Adjust Flavor and Enjoy!
Spicy kumquat pickles are great as a condiment with pork chops or roasted chicken, served like marmalade alongside a savory breakfast, added to salads or sandwiches, or as an appetizer paired up with crackers and cheese. Use the spicy juice in cocktails or mixed with sparkling water for an unusual and zesty flavor!