This image provided by the Statens Museum For Kunst shows the 1834 painting "The 84-Gun Danish Warship 'Dronning Marie' in the Sound" by Christoffer Wilhelm Eckersberg.

Danish painters in the 19th century had some special ingredients up their sleeves: They used materials from brewing beer to create their artwork, according to research published in the journal Science Advances on Wednesday, May 24, 2023.

This image provided by the Statens Museum For Kunst shows the 1834 painting "The 84-Gun Danish Warship 'Dronning Marie' in the Sound" by Christoffer Wilhelm Eckersberg.

Danish painters in the 19th century may have turned to an unusual source for some of their supplies: breweries.

Researchers examined paintings from the Danish Golden Age and found traces of yeast and grains. That suggests painters were turning to byproducts from local breweries to prepare canvases, they reported Wednesday in the journal Science Advances.

Study author Cecil Krarup Andersen said they went into the project looking for glue made from animals.

“Then, by surprise, we found something completely different,” said Andersen, a paintings conservator at the Royal Danish Academy.

The brewing leftovers would have been spread over the canvases as a paste, creating a smooth surface and preventing the paint from seeping through, Andersen explained. Today, this priming process is usually done with a white mixture known as gesso.

The authors said that knowing what’s on the canvases will help in conserving them.

In the study, scientists took a look at works by two of the first master painters to come out of Denmark — Christoffer Wilhelm Eckersberg, considered the father of Danish painting, and Christen Schiellerup Kobke.

To get a peek underneath their scenes of bobbing ships and family portraits, researchers used pieces of canvas that had been trimmed off the paintings in an earlier conservation project.