Determining recipes for some of the world's oldest preserved beers

Brian Gibson and colleagues explain that in 2010, divers discovered an old schooner at the bottom of the Baltic Sea near Finland. Archeological evidence suggested the ship went down about 170 years ago. It was loaded with goods including bottles of champagne and beer. The beer was diluted with salt water, but it contained enough of the original ingredients for the researchers at VTT Technical Research Centre of Finland Ltd. and the Technical University of Munich to analyze and get an idea of the initial recipe.

When the researchers took a sip, they weren't able to discern the beers' intended flavors. High levels of organic acids, produced by bacteria growing in the bottles for years, gave the samples vinegary, "goaty" and soured milk flavors that overpowered the original fruity, malt or hop profiles. However, analytical testing created a picture of what the beer may once have been composed of. For example, they determined that samples from two bottles were different beers based on their hop content. They also found that yeast-derived flavor compounds were similar to those of modern beers, though with a higher than usual content of rose-like phenylethanol.

The authors acknowledge funding from the Regional Government of Åland and the Stallhagen Brewery, which developed a replica brew based on the researchers' analysis.