Earthy Off Flavour – Possible Causes
Beer can have an earthy aroma and flavour, often described as soil-like or freshly dug earth. An earthy characteristic is usually caused by contamination, particularly from water or packaging. The compound responsible for the earthy taste is called geosmin.
What is Geosmin?
Geosmin is caused by the growth of microorganisms in any water that comes in contact with your beer or equipment. Beers with geosmin present are typically described as tasting and smelling earthy, dirty or contaminated.
Experiencing Earthy Off Flavours In Beer
To discover earthy off-flavours/aromas in beer, cover the glass with your hand and swirl it to release the aroma, then take short sniffs while holding the beer close to your nose.