Art conservation and historical remedies

​Posset, a mixture of wine or beer, spices, and cream that curdles and separates into a custard-like substance and an alcoholic liquid, may not tempt many palates today, but it was once popular in England and even considered medicinal for those who were ill. People consumed posset from a posset pot, a vessel with a spout and two handles, that was passed around a social gathering so that guests could both drink the liquid through the spout and dip a spoon into the mushy solids that rose to the top. Many posset pots can be found in museum collections, as Winterthur/University of Delaware Program in Art Conservation (WUDPAC) Fellow Haddon Dine learned this year when a 17th-century delftware, tin-glazed earthenware posset pot with a lid, accessioned in 2016 by the Winterthur Museum, became one of her treatment projects.

​The pot is decorated with blue butterflies and flowers painted on the white background created by the glaze. The date “1676” and the letters “C/WE,” possibly a monogram, are painted within the design on opposite sides of the pot. Overall the pot was in good condition, with chips and crazing common to tin-glazed earthenware, and museum curators hoped to put it on display. A major concern, however, was disfiguring earlier treatments. Haddon, an objects major with extensive pre-program experience in conservation science, found that these earlier restorations included replacement of the end of the spout, work on two areas of the lid where pieces had broken off and been reattached, and extensive overpainting of glaze chips.

​​After surface cleaning, Haddon used solvents to reverse the joins in the two reattached areas of the lid and to remove discolored overpaint. She was able to remove both the paint on the spout and the restoration fill material by applying cotton soaked with acetone and covering with plastic wrap.

Once the replacement piece and all remaining adhesive has been removed, and after researching the appearance of other posset pots, Haddon will sculpt a new, more appropriate-looking spout from a conservation-grade epoxy putty, and adhere it in place. She will also reattach the lid pieces and fill the small losses at the joins, using reversible acrylic paints to inpaint the replacement spout and other fills. Haddon looks forward to seeing the posset pot on display in the Winterthur museum once she completes her treatment and to knowing that her work will help introduce museum visitors to the history and wonders of posset.

A printable PDF version of this story is available here. Previous stories on projects from the Department of Art Conservation are archived and available here.