A history of flour milling at Molino la Ratonera

The Mill site

Before investigating the past one must understand the current layout of the site.

The mill tower, clearly seen on the right of the picture, is a conduit which carries water from the large mill pond to the 19th century mill building which is just visible immediately below the tower.

A culvert takes the water from underneath the modern mill to a channel on the far side of the mill owner's house, the building near the centre of the picture.

Beneath this building there are two ten metre deep shafts that take the water down to the old mill building which was situated to the left of and below the owner's house.

The old lower mill as it might have looked

The sketch shows the probable layout of the old lower mill.

This was a large site capable of processing considerable quantities of wheat with its three water wheels and three sets of millstones.

The technology used was the horizontal water wheel, known as a rodezno, with a direct drive shaft to the millstones.

The sketch shows it in a simplified form with the paddle wheel being propelled by a jet of water and turning the upper stone.


The arch on the modern mill bears the date 1894 but this is the recent past in terms of the history of the site.

The structure of the mill room suggests that it predates the arch and the discovery of an old floor under the current mill room together with the presence of the old mill wheel bearing (see photo) confirms the existence of a building on this footprint hundreds of years earlier.

The mill owner's house is a later structure some 100 years old built on older foundations.

The modern mill used a cast iron turbine to provide power to the mill stones and other milling equipment and was purchased second hand by the previous owners some 30 years ago.

The old lower mill site

The next photo was taken after the remains of the old mill earth and stone floor had been removed and shows the two mill arches with a bedstone above each.

The small metal rod to the right of the far millstone is part of the control mechanism, which would have raised or lowered the water wheel and therefore the upper mill stone (runner).

The Waterwheel

Although the rodezno was cheap to build it was very inefficient, requiring a huge head of water to provide sufficient power to turn the waterwheels at the required 110-120 rpm.

The upper mill utilized a wheel of approximately 1.8 metres diameter and, thanks to the massive mill tower, was powered by a 19 metre head.

The lower mills used slightly smaller wheels at 1.6 metres and were powered by a 10 metre head.

There are very few rodeznos left in working order in Spain but this old photo shows all the details.

The lifting control rod can be seen on the extreme left of the picture, the water jet, or chorro, protruding from the back of the arch and the wooden water wheel in the centre.

The water jet can be adjusted to control the amount of water and thus the speed of the wheel.

Feeding the mill

Horizontal mills like this were known in Spain as early as A.D. 800 with the vertical mill not introduced until the mid tenth century.

There is little evidence of widespread replacement of the rodezno with new mills being built during the middle ages.

Dating Molino la Ratonera is very complex.
The existing mill arches are unlikely to be earlier than sixteenth century due to the style of the stone work.
Parts of the mill tower appear to be pre-Christian and the style of the two kilometre channel that carries water from the river to the mill pond is identical to the Moorish acequias found in other parts of Granada province.

We have heard that some of the stones used in the tower came from Zagra castle when it fell into disuse after the routing of the Moors in the fifteenth century.
The mill tower has been made taller at some point in its history and this is most likely to coincide with the building of the mill pond.
Originally the water channel would have fed directly into the top of the mill tower.

Horizontal mills were cheap to build even when vertical mill technology was available but unless the river flow was unreliable in summer months the saving would not justify the construction of two kilometres of water channel, a large mill pond and 19 metre high tower.
The possibility of milling on this site before the sixteenth century is a very real one with the current structures being a modernisation of more ancient constructions.
This would explain the presence of the mill pond, tower and more modern rodeznos.

The used bedstone

What has happened since the sixteenth century is also difficult to understand.

One of the shafts to the lower mill has been blocked for many years, suggesting that was insufficient water to power both millwheels.

This idea is reinforced by the lack of any evidence of an actual wheel or iron drive shaft in one arch and the pristine state of the bedstone.
It has clearly never been used. These bottom stones lasted approximately 4 years so it may not be original but the miller is unlikely to have installed a new stone weighing over one ton and then not use it.

Adjacent to the other bedstone, which clearly has been used as seen in the picture, we found an unused runner (upper stone).
These lasted about three years and again weighed over a ton.

Its presence suggests an unplanned cessation of milling at the lower mill perhaps due to some catastrophe.

The old bread oven?

It was very common for bread making to accompany milling on the same site and this was the case at La Ratonera.

The upper mill contains a small selection of late nineteenth/early twentieth century bread making equipment and has been the site of the bread oven for many years.
This photo shows the ruins of what we believe to be the original bread oven to the side of the lower mill.

The section of wall on the right of the picture is one of the few parts of the lower mill that were still standing.

In living memory much of the land now devoted to olives was cultivated with wheat.

This was processed at the mill and bakery which employed 20 people with bread being transported to nearby Zagra by mule.

Milling at the site ceased in the late eighties while the last bread was baked in November 2004.