how long can I soak potatoes in water before they turn. I would like to prepare for the mashed potatoes before thanksgiving
They'll be fine for a day. Just make sure they're totally submerged, or the exposed parts will discolor.
As long as the potato isn't exposed to air, it will not oxidize.
We kept peeled potatoes in a bucket of water in the cooler of the restaurant i used to work at for about a week...so theyll be totally fine!