The OPAGA Spudbin by Golf Charlie and Mike Delta

Potato Storage Bin (Inset: fan assembly)

Potatoes in Store

This novel potato store idea was sent in to us - we're always happy to consider articles for the site.

The problem: feast or famine? Each year, our allotment delivers a healthy crop of spuds, but there is then the problem of storage.

Leave them in the ground until they are needed? Okay, but then that piece of ground is unavailable for other crops during the late summer and autumn, until the spuds have been lifted.

Dig them up and store? But we have not got a garage, shed, cellar, cool indoor place or suitable piece of ground for an old-fashioned ‘potato clamp’. Yet, we eat potatoes most days; if we could find a way to store them at home, it would minimise waste and weightlifting at shops, maximise convenience, and free up ground for other crops as soon as the spuds have been lifted.

So was born the outdoor OPAGA Spudbin. The idea went through several iterations (old fridge;freezer chest, cabinet?) before arriving at the current solution.

How the farmers store potatoes

The first step was to look on the Internet to find out how the professionals store potatoes. The answer was: on the floor of a dark storeroom, with forced under-floor ventilation, at a temperature of between 5 and 8°C, and humidity-controlled. So, how could we emulate these arrangements as closely as possible and at minimum cost?

The resulting Spudbin is a modified plastic wheelie bin with a combination of outside and inside treatment to keep the contents cool and well ventilated.

Outside of the Spudbin potato store

The bin has been sprayed metallic silver to reflect the sun; the outside sidewalls have been wrapped in an old mattress overlay blanket, folded double. The fold accommodates some old newspapers. The mattress and newspapers retain rainwater from the roof down-pipe and take heat from the bin by evaporation. The blanket is secured to the bin by a simple wire harness, which has upward extensions to holes drilled in the bin neck. The wet blanket is heavy.

Inside of the Spudbin potato store

A wire griddle is placed inverted at the bottom of the empty bin under a 4 ft length of plastic drainpipe for ventilation. The griddle and ventilation pipe are linked by four plastic cable ties. Four notches were cut in the top rim of the plastic drainpipe to receive a 12 Volt dc computer fan. The computer fan rectangular housing has corner holes, which serve as convenient attachment points for a cruciform wire bracing arrangement to holes drilled in the bin rim. This keeps the ventilation pipe upright under all load conditions.

There are some small gaps between the fan housing and the pipe, which have been plugged using blue tack to maximise vent pipe throughput. The computer fan is orientated to pump air downwards to emerge through the griddle and up through the spuds, and is driven by a solar panel.

Setting Up the Spudbin Potato Store

The Spudbin is located in a shady spot at the back of the house where it gets almost no direct sunlight and is adjacent to a rainwater down-pipe. In the summer, the blanket gets a weekly squirt of rainwater from the water butt as necessary to keep it wet. The solar panel is raised on an aluminium rod to which it is secured by a hose circlip and plastic cable ties. It points to the sky, southeast. The whirling fan is almost silent even in the hot summer sun, but delivers a satisfying, perceptible continual daytime draught through the spuds.

Storing the Potatoes

Before the potatoes were placed in the bin, any showing signs of disease or poor quality were separated. Any loose soil on the tubers was removed. The bin was placed on its side at a shallow angle and the potatoes rolled into the bin to minimise impact bruising. The wheelie bin has a big strong handle for returning to the upright position.

Experience of the Potato Store

Our allotment provided well over a hundredweight of spuds, which represented something over half a green wheelie bin. We measured the internal temperature at intervals with a probe lowered down the vent pipe to the bottom of the bin. In the summer, the temperature in the bin was generally about 5° C below ambient; in the winter, about 2°C below ambient.

The bin contents (including some parsnips) have remained in good condition throughout (as of end-January). The Spudbin also provides excellent protection from pests, which have no chance of illegal entry. When the bin contents get low, barbecue tongs have a good reach.

Construction Costs

You could build a Spudbin for next to nothing if you are good at scrounging.

• Green bin: free from the Council (if you do not already have one)
• Old blanket: ‘volunteered’ from the bottom of a pile of disused items; thanks Mariann.
• Newspaper: Bristol Evening Post or Thornbury Gazette
• Silver Paint: Leftovers from car spray job that I never did. White would do.
• Steel Wire: String will do, or a length of redundant electrical cable.
• Griddle: About £6 less the OPAGA discount in Thornbury.
• Plastic Pipe: Thanks, Angus
• Computer Fan: Thanks, Steve
• Blue Tack: Village Post Office
• Solar Panel: Maplins. Special offer, £12; (try before buy).
• Plastic cable ties (brilliant invention): a few pence at Maplins. Do yourself a favour and buy a big box full).
• Circlip: B&Q ( £1. 10% Wrinkly discount on Wednesdays).

We had a lot of fun putting this together (I hesitate to say ‘design’). But the bottom line is: it works