Stainless steel sides burning food
"But disc bottoms make lousy sauce pans or fry/saute pans, because the sides burn food."
so on that website its said that the sides of a SS pan that only has alminum core in the bottom and not in the sides would burn food on the sides of the pan.
but if the base is encapsulated and the sides are not, i would think the sides are cooler than the base. how can food burn only at the sides? what is the explaination?
I think they're mostly talking about disk bottoms which don't go all the way to the edge. The metal is much thinner right on the edge (thinner than the parts covered with an aluminum or copper disk), and stainless won't diffuse heat as well, so if the heat is too high, that part of the pan will overheat and you may get some burning. With a small pot on a gas stove, having the flame very high may cause the flames to actually even spread up the side of the pan, making the problem worse.
It's a problem that bothers some people more than others, and may also depend on your heat source and cooking habits. I find that I can usually work around it as long as I don't use too-high heat, but sometimes with sauté pans and skillets, it is a minor issue. I have both types of cookware, and while I like multi-ply cookware, I don't think it's necessary for every application.
One other note - while I usually think that multi-ply fully clad pots are overkill for stockpots, I will say that I have a new tri-ply Vollrath "Tribute" 8 qt sauce pot / stock pot, and the aluminum cladding up the sides does seem to make it retain heat well; for example, after adding pasta to cooking water, the pot seems to return to a boil almost instantly, despite being a bit wider and shorter a shape than I'd usually use for this purpose.