I've been using a Sekonic light meter in spot mode for over a year now with the zone system, and I have consistent issues with snow. Despite putting the snow on zone 8, that area of the negative ends up being very dense, more like I would expect zone 9.5 to be. I originally thought I was doing my calculations incorrectly, or that I was measuring snow + rock and therefore not really reading the snow, but I've recently confirmed that a solid zone 8 placement was dramatically overexposed and required significant burning to get any detail. To correctly expose snow I have to assume 1-2 stops of light beyond what the light meter records.
Is this an issue with my light meter? How do others correctly expose snow in their black and white film shots? Do you just assume an overexposure and underdevelop the negative?