Our work at Houghton Mill

A person working on paddle wheel maintenance at Houghton Mill and Waterclose Meadows, Cambridgeshire. — Paddle wheel maintenance at Houghton Mill | © National Trust Images/Mike Selby

Find out about the work we do throughout the year to keep Houghton Mill running smoothly. It's the last surviving mill on the River Great Ouse able to produce stoneground flour from a water-powered wheel. We want to make sure we preserve it for visitors to enjoy now and well into the future.

Keeping the wheel turning

The impressive waterwheel you can see today at Houghton Mill is one of the largest in the UK. But when the mill was closed in 1928 the waterwheel was removed.

Bringing the waterwheel back to life

In 1983 The National Trust opened Houghton Mill to the public and, following repairs, the mill was able to start making flour once again. However, although the flour was milled using the original millstones, they were powered by an electric motor as the waterwheel had not been restored.

Finally, after over 70 years and with the help of a grant from the National Lottery Heritage Fund, we were able to reinstate a working waterwheel in 1999.

Keeping the mill running when water levels are low

These days the river flow is controlled by the Environment Agency. In 2013 we installed a new set of electric-powered millstones. This means that visitors can still experience the sights and sounds of the mill in action, even if the conditions aren’t right for the traditional waterwheel to operate.

Conserving the waterwheel

Every 10 years or so we need to carry out essential maintenance on the waterwheel to make sure it will continue to operate smoothly.

During the winter of 2019/2020 professional wheelwrights took apart and rebuilt the sluice gate. Over the summer of 2020 the volunteer team at Houghton Mill replaced 30 oak floats and 30 sole boards.

Two people working on millstone maintenance at Houghton Mill and Waterclose Meadows, Cambridgeshire. — Millstone maintenance at Houghton Mill | © National Trust Images/Mike Selby

Houghton Mill’s annual millstone inspection

When Houghton Mill is open for the season, it can produce up to 150kg of flour on each milling day.

The mill uses French burr stones and the same traditional methods used over 150 years ago. Milling flour using 18th-century machinery is a noisy and very physical process that can eventually take its toll even on even the most hard-wearing of millstones.

Each year specialist millwrights Dorothea Restorations and our experienced volunteer millers work together to inspect, clean and prepare both pairs of millstones for the year ahead. Here’s how it’s done:

The casing is removed and the stones are separated

Before the millstones can be inspected, our millers carefully take apart the wooden casing. This is what protects the millstones (and our visitors) when they are in action. A stone crane is used to raise the top running stone.

The inner surfaces of the millstones are inspected

The millwrights inspect the inner surfaces of the millstones to check for any uneven wear, glaze or moisture damage. They also measure how deep the furrows are.

The running stone is measured

The high-quality burr stones used at Houghton Mill should only need to be replaced every 100 years. However, every few years they will need to be redressed to make sure they work efficiently.

Any grain is removed from the bearings

The neck bearing is taken apart, any grain is cleaned away and it’s then greased.

The 'furniture' is replaced

The millstones are put back together and the ‘furniture’ (tun, quant, horse and shoe) is put back around the millstones before a test run of the waterwheel.

Ready to mill

When the millwrights and millers are happy everything is working, we’re ready to start producing freshly milled Houghton Mill stoneground flour again.