Hi Lois,

Al is right. Potato starch and potato flour are two very different things. I've run across sites that say they are the same and interchangeable - apparently those people have never tried baking with them.

I've been substituting a small amount of potato flour in place of the same amount of potato starch in some recipes. The buns I've made doing that have come out moister, more tender, and not crumbly. Substitute too much and the end product will be very dense, very heavy, very moist, and may not bake completely. Yup, that loaf got tossed. Baked it 2 hours and it still wasn't done!

I have heard of some people who have used instant mashed potato flakes in place of potato flour - not potato starch, but I haven't tried it. If you do, make sure to check the ingredients to make sure it's pretty much just potato.

You can sub corn starch in place of potato starch. I had to do that when making buns one day, and they came out just fine. I believe you can sub arrowroot as well, and others I think, but I haven't tried any of them either.

Good luck!