Quick pickled summer squash

Adapted from the Gramercy Tavern Cookbook

2 1-pint mason jars with lids (or other heat safe containers)
2 lbs summer squash (about 4), sliced thin with a knife of mandolin
1 1/2 cups rice vinegar (unseasoned)
½ cup water
½ cup sugar
2 tablespoons kosher salt

1. Pack half the squash into each jar. 
2. Make pickling liquid: Add rice vinegar, water, sugar, salt, and mustard seeds to a medium saucepan; bring to a boil over high heat, stirring occasionally so the sugar doesn’t scorch.
3. Pour hot pickling liquid over kohlrabi, leaving about ¼ inch headspace; place lids on loosely; let cool to room temperature (~1 hour); tighten lids and refrigerate. Keeps in the fridge for a few months.