Ostfriesentee is a special, strong tea mixture from East Frisia; It consists of up to ten black tea varieties, especially Assam tea. But also tea from Ceylon, Africa, Java, Sumatra and Darjeeling teas are mixed to it.
In East Frisia are three large tea houses located (Bünting, Thiele, Onno Behrends) of which each offers several own tea blends. Usually, only tea that has been mixed in East Frisia, referred to as genuine Ostfriesentee. The genuine Ostfriesentee is mixed from over 20 different types of tea, since only the composition of many varieties consistently high quality results and in this way small variations in quality of the individual components (tea batches) are compensated.
The designation "Ostfriesentee" is not protected, so that many teahouses outside of East Frisia also offer black tea blends under this name or as an "East Frisian blend". Only word marks such as "Bünting Tee echter Ostfriesentee" are registered as registered trademarks at the German Patent and Trademark Office.