Zucchini Dill Pickles

INGREDIENTS

• 2 pounds small zucchini (preferably about 4" or 8" long), trimmed
• 4 tablespoons coarse sea salt or pickling salt, divided
• 12 fresh dill sprigs
• 2 teaspoons yellow or brown mustard seeds
• 1 teaspoon coriander seeds
• 1 teaspoon dill seeds
• 1/4 teaspoon saffron threads
• 4 garlic cloves, halved
• 4 red jalapeños or Fresno chiles, split lengthwise
• 2 1/2 cups white wine vinegar
• 1/4 cup sugar