Step 1

Wash the jars, lids, rings in warm water and rinse well. Set aside to dry or dry completely by hand.

Step 2

Rinse the asparagus under cool running water and drain well. Halve them if using short, pint-sized jars. Leave whole if using a quart jar.

Step 3

Add the garlic, red pepper flakes, mustard seeds to the jar. Tilt the jar on its side. Tuck the dill sprigs in first, then stack the stalks inside the jar, orienting them so that they will stand up vertically when the jar stands upright. Pack the jar as tightly as possible with stalks. A full pound should fit into a one-quart jar, or about 1/2 pound in two pint jars.

Step 4

In a small saucepan over high heat, combine the vinegar, water, sugar, and salt. Bring to a boil. Pour the pickling brine over the asparagus, leaving about 1/2 inch headspace at the top.

Step 5

Gently tap the jars against the counter a few times to remove all the air bubbles. Top off with additional pickling brine if needed. Place over the jars and screw on the ring until tight.

Step 6

Let the jars cool to room temperature, then store the pickles in the refrigerator. Wait 24 hours before opening. The pickled asparagus will get more flavorful as they age.