Conkers, which are the nuts of the horse chestnut tree, are not safe to eat raw as they contain a toxic compound called aesculin. Eating raw conkers can cause stomach upset and nausea. While conkers can technically be made edible by cooking and processing (such as making conker flour and leaching out toxins), they have a bitter taste and are generally considered unpleasant to eat. Thus, conkers are not commonly eaten in the UK and should be avoided as food. In contrast, sweet chestnuts (from a different tree) are edible and widely enjoyed, but horse chestnut conkers are distinctly toxic to humans and many animals. Some mammals like deer and wild boar can eat conkers safely, but they are toxic to others including dogs. Conkers are mainly used for crafts, games, and sometimes in soaps and shampoos due to their soap-like chemicals called saponins. In summary, in the UK, conkers should not be eaten raw and are generally regarded as toxic and inedible , though they can be processed to remove toxins but still do not taste good.
