3teaspoonscoarse sea salt (or 2 teaspoons fine grain sea salt)
Preheat oven to 375. Scrub sweet potatoes and pat dry. Line a large baking sheet with nonstick foil and spray generously with cooking spray.
Thinly slice sweet potatoes into round discs. You can use a mandolin slicer if you have one, I did not, so I used a really sharp knife and that worked great. Place all of the potato discs in a large plastic zip lock bag. Add malt vinegar, seal, and shake to coat the potatoes. Allow to rest at room temperature 10-15 minutes.
Drain the bag and place all of the potato discs in a single layer on prepared baking sheet. Sprinkle with half of the sea salt and spray generously with cooking spray. Bake 15-20 minutes. Use a thin spatula to flip the potato discs over. Sprinkle with remaining sea salt. Bake another 15-20 minutes until chips are crispy. Remove and allow to cool completely. Store in airtight container at room temperature.
Store in airtight container at room temperature up to five days.