A Couple Quick Questions on Glassware

1. Unless the glass is significantly thick, any affect is minimal. Thickness affect heat transfer from environment and hands to the beer. I wouldn't worry much about this affecting the overall experience, but more so the shape and size of the glass for a given beer.

2. Can't say I've heard either of these claims, but dirty glassware, evident by masses of bubbles clinging to the side of the glass, just makes the pour unpleasant to look at. Maybe more dirty = more bubble = more "retention"? Probably not significant either. The presence of head depends on the beer, batch, etc., but again, also the shape of the glass. Teku for example is outstanding at maintaining head retention due to the way it's shaped. That said, bubbles lasts longer in colder temperature because the evaporation rate is slower, causing less bubble retention. That probably affects the head retention.

 

1. There are some claims that thinner glasses help keep temperature and provide a better flow of the beverage onto your mouth improving taste. Caveat Emptor.

2. Dust, soap residue and small fibres (from towels for instance) decreasing head accumulation and retention. You definitely want a clean, well rinsed, air dried glass if at all possible.