How to Make the Ultimate Umami-Bomb Vegetarian Demi-Glace
1 cup kosher salt
1 1/2 gallons water
5 1/2 pounds Kirby cucumbers, sliced crosswise on a mandoline 1/8 inch thick
5 cups cider vinegar
5 cups sugar
1 1/4 pounds onions, thinly sliced
2 tablespoons yellow mustard seeds
1 tablespoon celery seeds
1 tablespoon turmeric
1 tablespoon coarsely cracked black pepper
In a very large bowl or pot, dissolve the salt in the water. Add the cucumbers, cover and soak overnight in the refrigerator.
In a large, heavy pot, combine the vinegar and sugar and cook until the sugar dissolves. Stir in the remaining ingredients. Drain the cucumbers and add them to the pot. Stir gently and bring to a boil, then turn off the heat. Ladle the hot cucumbers and their liquid into 6 hot 1-pint glass canning jars, leaving a 1/2 inch of space at the top. Close with the lids and rings.
To process, boil the jars for 10 minutes. Cool the pickles to room temperature and serve immediately or store them in a cool, dark place for up to 1 year. Refrigerate after opening.