Stirring equipment for biodynamic preparations: vessel, stirrer, stirring machine

What do you need to stir the preparations?

Horn manure, horn silica and barrel compost are stirred in water before they are applied, the dynamisation. This takes two things: a vessel in which a deep vortex can form, and a stirring tool that offers the water resistance. How much water you stir decides which technique fits. In the garden a bucket or a stirring pot and the bare hand are enough. On the farm a stirring barrel with a suspended stirrer or a stirring machine is added.

The stirring vessel

• Shape: round in cross-section, cylindrical, with smooth walls. Bulging wine barrels and vessels with pronounced shoulders make the vortex collapse early. A slightly conical barrel, wider at the bottom, stirs easily and hardly spills.
• Proportion: taller rather than wide, roughly diameter to height 1 to 1.6 or 2 to 3.
• Filling level: two thirds at most, a bucket only half. The water rises at the edge while stirring.
• Material: wood, stoneware, glass, copper, stainless steel or enamel. Galvanised metal, aluminium and rusting oil drums are ruled out; plastic only where nothing else is available. The vessel must be clean and must never have been in contact with chemicals or essential oils.
• Bottom: a curved bottom collects no sediment in the corner.

A 200-litre barrel is about 58 centimetres across. That is too wide for most people to stir vigorously. How to stir is explained under dynamisation.

Hand stirring tools

The stirring tool must offer the water resistance. A thin stick slips through the water and the momentum is lost. Tightly bound bundles of birch twigs, turned wooden tools and star-shaped stirrers made of slats have proved their worth. The immersion depth matters: if you only stir in the upper half, the lower half never gets moving.

Stirring with the bare hand has its own advantage. You feel the temperature, notice when the horn manure does not disperse well and correct it at once.

How much water you can stir by hand

For most people 120 litres is the upper limit if the stirring is to be really vigorous. The measure is whether you get the water moving at once so that it carries you along. Masson advises stirring no more than 120 litres at a time by hand and no more than 250 litres by machine (Masson 2015).

Building your own stirrer: the suspended stirring tool

With a suspended stirrer the stirring pole hangs from a pivot centred above the barrel. Its weight is no burden and the leverage allows the largest quantities of water. You stir standing, can stir together and take turns without interruption (Stappung, ch. 16.6).

The parts of such a set-up are the supporting frame, the suspension and pivot point, the stirring pole and the stirrer itself. The suspension is carried by a ceiling beam or by two or three beams or poles fixed to the barrel. Georg Merckens gave the most precise dimensions in 1960 (after Stappung, ch. 16.6):

• a broom of coarse birch twigs, about a quarter as thick as the barrel diameter
• at the top it just sticks out of the water, at the bottom it is cut straight 5 centimetres above the barrel floor
• a perfectly straight stirring pole
• the barrel filled to three quarters at most, usually no more than 160 litres

While stirring, the elbows are best just above the rim of the vessel. Smaller vessels are therefore raised.

Stirring machines

Large farms and special crops that spray often also stir by machine (Masson 2015). Most stirring machines imitate hand stirring with a motor and reverse direction on a timer. Machines on the Australian model trigger the reversal with a level sensor as soon as the vortex reaches a certain height, which brings them closer to the rhythm of hand stirring (Masson 2015; Wistinghausen et al., application, ch. 2.3.6). Flowforms are also used, cascades in which the water runs in oscillating vortices.