This was a new experiment, based on this recipe for quick pickled jalapeños.
6 oz. water (3/4 cup) 6 oz. white vinegar (3/4 cup) 0.6 oz. Kosher salt (2 tbsp.) 1 clove garlic, minced 1/2 tsp. oregano (dried) 5 jalapeños, sliced, with seeds and ribs
Bring all of the ingredients except the jalapenõs to a boil in a small saucepan.
Fill a pint canning jar with sliced jalapeños. The original recipe said 10, but I only got 5 in, though they were unusually large jalapeños. And once they settled I could probably have added one more.
Let cool, then refrigerate. Store in the refrigerator.
Update #1:The really want to float when you add the brine, until it gets absorbed. Sticking a 4 oz. canning jar on top of the jalapeños in a 16 oz. wide-mouth canning jar until cool works.
There is a possibility that as the peppers settle and cool, the jar will sink in to a point where the brine overflows the jar, so beware of that. Now I just wait until I vacuum seal the canning lid on the jar, then flip it upside down. That's much easier and it reduces the chance of contamination and mess.
Update March 16, 2015: I removed the sugar and doubled the salt, which makes about 1:20 brine ratio from Michael Ruhlam's Ratio cookbook. I like it better this way. The original recipe was:
3 tbsp. sugar 1 tbsp. Kosher salt