Add the potatoes to a large saucepan and cover with cold water by 1 inch. Add the baking soda and 1 tablespoon salt to the water. Cover, place over medium-high heat and bring to a boil. Uncover and continue to boil until the potatoes give easily when pierced with the tip of a knife, 15 to 20 minutes. Drain the potatoes and set the strainer over the top of the pan for a few minutes so the outsides of the potatoes can dry.