How can a wine with moderate to low alcohol, no RS, taste high in glycerol?

Glycerol only imparts a slight sweetness to the wine. While the wording of your question is rather economical, I suppose you are refering to something else than that sweetness? It is generally ascribed a lot of properties, but viscosity is only affected byt it very little.

You are correct. Looking for why a collection of wines, from the same winery in Alexander Valley, many different varietals, all taste very viscous.
Thank you so much for your responding. I've been looking for some time.

Are you talking about white wine in particular? I had a very interesting tasting of 05 Chardonnays over the weekend. Half the samples had not gone through ML while the other half had fully completed the secondary fermentation. Both sectors were dry (>2% RS) but the ML portions were as thick as Sauternes at this stage. My best guess so far is that the wines you are talking about have gone through ML, hence the increased viscosity. The lactic acid (same as in milk) is much heavier and can give you the impression you are describing.

Interesting information on the effect of glycerol on viscousity here and here.

PH

Great links PH. It would be a very tough task to argue with Waterhouse or Noble in this area.