Set your sous vide water bath to desired temperature according to the chart above .
In a large bowl, toss shrimp with ½ teaspoon kosher salt and the baking soda. Place shrimp in a heavy duty zipper-lock bag or a vacuum bag. If desired, add 1 to 2 tablespoons (15 to 30ml) olive oil or butter and aromatics. Remove all air from bag using the water displacement method or a vacuum sealer. Press shrimp into a single layer.
Add bagged shrimp to preheated water bath and cook for at least 15 minutes (see note) and up to 1 hour. Remove shrimp from bag to a paper towel-lined plate. Serve hot, or chill and serve cold.
