Unfortunately, in our fast paced world of wanting everything NOW, restaurants and pubs tend to throw a bunch of soap on a beer mug, maybe dip it in a sanitizer, and than rinse it in a nana second, and stick it on the rack. This is not to say the glass is not ‘clean’ … but it is not beer clean! A dirty glass can kill the taste of a great beer.
One immediate tell tale is your beer appears flat – absolutely no head of foam and no bubbles floating to the surface – the mental image hurts! If the glass is properly cleaned, the sides of the glass should have a lacing effect with every sip from the head of foam; the head should remain in tact for most of the beer; bubbles should constantly rise to the top; and no bubbles should cling to the side of the glass.
You certainly do not want to appear as a pushy beer drinker, but if your beer appears flat, it is most likely not enjoyable and should be sent back and exchanged for a beer in a clean glass.
