Old Margarine Powder, Old Milk Powder

I decided to start opening every old can in my food storage.  I figured it would either be good, and I would eat it, or it would be bad, and I would throw it away, thus clearing a space for some new food storage.

So I opened this can of margarine powder from 1988, and used this milk powder from 1991 (which I knew was good, because I've been using it for a few months already.)

I made some buttercream frosting, from powdered sugar, margarine powder, milk powder, and water.

My oldest son was visiting, so I offered him a snack of graham crackers with the frosting.  I was curious to see if he would notice any difference with the taste.  He ate it happily with no comment.

So, the verdict is that 22 year old margarine powder still tastes fine in buttercream frosting.