In another jar, combine the salt, sugar, mustard seeds, sliced shallots, vinegar and white wine (add dried herbs if using) and shake until the salt and sugar dissolve. Add 1 cup of water and pour the brine over the vegetables.
Tuck the tarragon sprigs between the vegetables. Add enough water to cover the vegetables and keep them submerged. Close the jars and refrigerate overnight or for up to 1 month.
Notes
Kosher Salt - do not use iodized table salt, can also use pickling salt.
Mustard Seeds - white or brown.
White Wine Vinegar - preferably 6% acidity
Tarragon Sprigs - can substitute dry, but fresh is ideal.
Use fresh herbs when possible. If using dried, depending on the strength of the herb, one half to one teaspoon per jar is usually enough.Refrigerator pickles need to age for a couple of days before sampling to let the pickled flavor develop. You can eat them earlier, but they are best if allowed to brine for a couple of days.You can reuse refrigerator pickle brine two times as long as it is not murky or cloudy and hasn't been heated up. So, if you pick up another bunch of asparagus, make another batch!You can also use other vegetables with this brine - cucumbers or zucchini would be good!