I don'r know what grade of stainless steel this is, but I have never seen a pot discolor after only one use. I have been buying Tools of the trade cookware for the last 15 years, and still have all of them clean and like new. I bought this one for boiling pasta and making soup. After the first use it rusted on the inside only. The rust spots are permanent - can not scrub them off. I wont not use it again, as this cannot be good for your health. Would like to return it, but don't have the original packaging, and do not know when i'll be able to go to the store during this Covid -19 situation.