Combine water, vinegar, sugar, and salt in a saucepot and simmer over low heat, stirring often, until the salt and sugar have dissolved. Set aside until ready to use.

Trim the onions and slice into thin strips. Toss onions with 1 ¾ tsp pickling salt and allow to sit for about 30 minutes, then rinse. 

Evenly distribute the peppercorns and bay leaves between the pint jars. Add about 1/2 lb of sliced onions to each jar. Gently press down with tongs to make sure the jar is loosely packed with onions. 

Cover with brine, leaving about ½ inch of headspace. Once the jar is full, tap the jar lightly to dislodge any air bubbles. Check the headspace again and add more brine if necessary. 

If making refrigerator pickles (not processing/canning), make sure your brine is hot when you pour it over the onions. 

Let the jars return to room temperature, put the lids on, and store in the refrigerator for up to two weeks. The longer they sit the more they’ll pickle. 

Clean the rims of the jars with a damp paper towel or clean kitchen towel. Place the lids on the jars and seal with the bands using just your fingertips so that they are not too tight. 

Process for 10 minutes using the boiling water bath method. As soon as the timer goes off, carefully remove the jars using the jar lifter. Place them on a clean towel and allow to cool undisturbed for 24 hours . 

After 24 hours you can remove the bands and test your seals by lifting the jar, by the lid, a few inches from the counter top. If the lid supports the weight of the jar, the seal is good. Jars with good seals can be kept in a cool dark place for up to a year. If the seal is broken, store in the refrigerator and use within 2 weeks.