I don't know if this is common knowledge or not, but I just came up with a great storage method for potato water and wanted to share. When you boil potatoes, save the water and put it in the fridge. Once it's cool, I pour it into ice cube trays! Then it's divided into nice 3/4-1 oz. pieces that'll keep for pretty much forever in a freezer bag. I was inspired by Alton Brown's similar method of storing egg whites.
It seems to me that if its cool, all the starch has settled towards the bottom...
If I don't use it within 6 hours, it gets refrigerated. If I don't use it within 24 hours it gets pitched. I would never freeze it unless I would use the icecubes soon after to cool down the dough, say in summer. It looses it quality quickly so best used quickly.
An update on this: I used the potato water for the first time yesterday, and it worked out! The bread tasted normal and the crumb was very tender.
Also, I was reading Peter Reinhart's WGB and noticed that he suggests refrigerating potato water for up to 5 days, or freezing it for months.
Is the potato water salted? And if so, how do you know how much to adjust the salt content of the dough?
-Elizabeth