The nine Biodynamic preparations 500-508 are the essence of and are unique to the Biodynamic way for farming and wine-growing. The names of these nine preparations (‘preps’) are Horn manure 500Horn silica 501, Yarrow 502, Chamomile 503, Stinging nettle 504, Oak bark 505, Dandelion 506, Valerian 507, and Equisetum arvense 508 (Common horsetail). Their regular application to the land via compost or liquid sprays is a pre-requisite for any vineyard or other agricultural enterprise to be considered Biodynamic by Demeter, the organization which has regulated Biodynamic farming since it was first described in 1924 (see also Biodynamic certification).

The nine ‘preps’ are made from one or seven wild plants, or cow manure, or the mineral quartz (silica). The preps help regulate the farm and the crops, be they perennial wine grape vines, annual vegetables, or farm animals. The idea is that all function healthily, and in a way that also allow them to tune in to both the Earth’s seasonal cycles (autumn, winter, spring, summer) and celestial cycles as a whole, so that the formative forces which Biodynamic farmers see as being able to shape matter (vines, shoots, leaves, buds, vine flowers, grapes, pips, tannins) can do so in the best way.

Three Biodynamic field spray preparations 500, 501 & 508 are sprayed directly on the vineyard or farm individually and at different times during the season. They are Horn manure 500, Horn silica 501, and Equisetum arvense 508 (Common horsetail). Each one is used in isolation and first stirred or ‘dynamized‘ in water. This stirring allows the ‘formative forces’ in each preparation to be transferred to the water and then onto the cropland. The use of water also makes practical sense as it would be impossible to spread Horn manure, Horn silica, or Equisetum arvense across large areas of cropland when only handful or so of each prep is required per hectare per treatment. 

Six Biodynamic compost preparations 502-507 are added to the compost pile. They are Yarrow 502, Chamomile 503, Stinging nettle 504, Oak bark 505, Dandelion 506, and Valerian 507. The Biodynamic idea of composting waste generated by the farm/vineyard and returning it to the land aims to maintain each farm as self-sustaining living organism. The ‘farm organism’ idea later became the origin of the term ‘organics’ which followed on from Biodynamics and dates from the mid-1940s. Vineyards able to create and maintain their own fertility might be said to be practising ‘terroir-enhancing’ wine-growing.

Those who are unable to apply the six Biodynamic preparations to the land via compost may insted do so via sprays such as Maria Thun’s Barrel Compost, Peter Proctor’s Cow Pat Pit, or as Alex Podolinksky’s 500P. In addition, plant-based sprays (decoctions, teas, liquid manures) are also used in Biodynamics (and of course organics) on the ‘use a plant to cure a plant’ principle.

Measuring the effects | Diagnostic tools to gauge whether the often fairly left-field (‘unscientific’) practices used in Biodynamics actually work include–most obviously in wine’s case–comparative blind tastings between conventional, organic, and Biodynamic wines. Less conventional diagnostic techniques peculiar to Biodynamics include sensitive crystallization and chromatographySee also setting up a comparative trial between Biodynamics and organics. 

See also the work of Claude and Lydia Bourguignon