The leading brown sauce in Britain is HP. The leading brown sauce in the US is A1.
Broadly speaking, A1 is a cross between HP Sauce and Worcestershire Sauce. HP is sharper and thicker, whereas A1 is a little more fruity. You can find the imported American sauce in larger Tescos in the UK (£5.50). It is an excellent accompaniment to beef, and goes well in casseroles and meatloaf.
A1 is a British invention, introduced by Henderson William Brand in 1862, when he was co-manager of the cuisine at the International Exhibition in Hyde Park. He submitted the sauce before the Royal Commission for use in the Exhibition’s restaurants. The Chief Commissioner reportedly declared the sauce to be “A.1.”
The A1 name as applied to sauce was first trademarked in Britain in April 1890. The trademark was first registered in the US in June 1895. It was initially distributed in the US by Del Monte, until Heublein acquired the rights in 1906. Heublein later gained production rights as well.
A1 was phased out in Britain in the 1970s, forced out of a crowded brown sauce market which included HP, Daddies and supermarket own-label nationally, as well as OK, Heinz Ideal, Hammonds and Fletcher’s Tiger Sauce at a regional level.
The brand is currently owned by Kraft in the US. In Britain, the trademark is currently owned by the British food giant Premier Foods, who acquired the former owner Rank Hovis McDougall.