However, it seems reasonable that melted snow contains less, or even no, mineral salts. What should the difference be? If any, water without the minerals is a somewhat less polar than water with the minerals. Melted snow might give a different extract since most of the extracted compounds from coffee are nonpolar. If mineral-free water does result in over-extraction, so should distilled water, since this is an efficient way of removing minerals (of course, there is the matter of dissolved gases such as CO2 etc.).

Any knowledge whether blind tests have been conducted comparing melted snow and distilled water for any kind of coffee or tea? Or maybe analyses of coffee made from distilled and non-distilled water?

One example of the mineral salt effect: isopropanol (i.e. “dry-gas” fuel additive) and pure water mix well. If salt is added to this mixture, the two solvents separate; salt water on the bottom and isopropanol on top (the isopropanol would represent compounds extracted from the coffee). The reason is that the salt dissolves in the water, rendering it more polar and less miscible with the isopropanol (the isopropanol represents the aromatic compounds from coffee).

Btw: using snow for drinking water and cooking is rather common for those hiking (or staying in primitive cabins etc.) during wintertime in areas with the appropriate climate.

Snow is not groundwater (duh) so therefore has no minerals. Thus it is super soft.
soft water over extracts because it naturally wants to take on minerals, thus sucking more out of the coffee – just like a sponge wants to take on water!

though a touch overextracted

Does that mean that you should have used less snow?

As a Norwegian I can confirm that I grew up learning that I shouldn’t eat snow because it might have worms in it, the same way we parents make up silly stories in order to prevent kids from doing stuff we don’t want them to do. Nowadays, kids aren’t that easy to deceive (they’re all postmodernists). Hence, we’ve switched over to discouraging eating snow from the streets and the yellow snow along lamp posts..