ANDREW BROOKES, NATIONAL PHYSICAL LABORATORY / SCIENCE PHOTO LIBRARY ANDREW BROOKES, NATIONAL PHYSICAL LABORATORY / SCIENCE PHOTO LIBRARY
Beer. Five different beer brews in various types of pint glasses. The varying colours are due to the different conditions that each beer is made under. Such influences include: the alkalinity of the brewing ingredients (higher alkalinity gives a darker colour), the brewing time (darker beers are brewed for longer), the colour of the hops (plants fermented in brewing) and the degree of filtration (a highly filtered beer has a clearer and lighter colour).
Model release not required. Property release not required.