
Fermented baltic heering is a Swedish speciality. It is heering from the baltic sea that is slightly salted – just enough so it do not rotten. Then it is fermented in tin cans. Heering is named stroming. Sour stromming – syrstromming. This ends up surstromming, fermented baltic heering.
Fermented baltic heering smells so horrible that you have to open it outdoors. It is an experience of a lifetime and you will find many pages on the web about surstromming – fermented baltic heering.