Flag Porter is brewed from a traditional 19th century British recipe using yeast salvaged from a vessel which sank in the English Channel in 1825. In 1988, several bottles of the brew were raised from their resting place 60 feet deep in the Channel. They were in their original containers, with their wood stoppers and wax seals intact. When opened, however, they "tasted like old, wet boots" according to Dr. Keith Thomas, renowned brewer and microbiologist. When he examined the beer under a microscope, he found a small percentage of the yeast to be still living! After months of growing this yeast, he brewed a porter using an 1850 recipe. Adhering to the practises of porter brewers of the era, Dr. Thomas uses barley and hops grown without pesticides or chemical fertilizers.