The oil mill was already located on the Mühlbach stream in Unterweiler around 1700. Until around 1920, rapeseed and nut oil, but also grain, were milled here. The mill wheel was also used at times to operate a “grinding mill” (for sharpening tools), a “hemp mill” (for crushing and breaking up hemp stalks), or as a “gypsum mill”.

The adjacent vineyard site “Ölberg” derives its name from the oil mill.

In 1790, the stuccoist Fehner produced paints and “plaster” from the barite found in the valley for the construction of the new parish church.