formed in 1972, is a group of homebrewers dedicated to recreating beers from the 18th and 19th centuries. Led by the late Dr John Harrison, they delved into many old brewery records to uncover details of commercial beers from these periods. Often brewers used codes to keep their products’ composition secret from would-be competitors. After unraveling these codes to reveal the original recipes, the Circle endeavored to reproduce and critically taste the beers themselves. Some members even developed their own methods of producing old-style malts, such as brown and amber malt, which were no longer available in their original forms.

The group remains active and its research efforts are compiled in a book, which has undergone three revisions and is a mine of information on brewing beers from previous centuries. It contains details on the brewing techniques used to reproduce these beers, together with 131 recipes for such beers as London and Irish porters, stouts (both Imperial and Double), Scotch, amber, mild, March, and October ales. Also included is a section explaining the origin of each of these styles, along with descriptions of their defining characteristics.

Even more interestingly, there is a section showing how to decipher recipes from old brewing texts and brewers’ books. Examples are given, including one of a typical brewer’s code and its interpretation. Although this small book is aimed at homebrewers, it is a work of some significant scholarship.