Farmhouse ale
The Farmhouse ale is an ancient European tradition whereby farmers would produce beer for their own consumption using their own grain. Most farmers brewed ales for consumption during Christmastime and/or work in the late summer, but those with a plentiful-enough grain supply brewed for everyday drinking. Farmhouse ales do not constitute a single beer style; they vary significantly in terms of the ingredients and brewing process used, both of which follow ancient local traditions.
Many microbreweries and craft breweries in the present day market products as farmhouse ales, but in most cases, their connection with the actual farmhouse brewing tradition is rather tenuous. Breweries in Belgium and Northern France, for example, claim to sell beers derived from those traditionally brewed on local farms. This connection is not well-documented, however, and it is unclear how close these commercially-brewed offerings are to the farmhouse-brewed originals.
A notable exception are the commercial farmhouse breweries in Finland, Estonia, and Lithuania. These businesses brew on farms according to the ancient traditions, and some of them still use the original farmhouse yeast.