Urban Food Chains

the links between diet and power

Seasonality

It might seem odd to a modern observer that 1925 the UK’s ministry of labour classed the following foods as seasonal: fish, milk, butter eggs and potatoes. The fact that prices and availability might change quite widely across the seasons is the argument advanced for ignoring such basic foods when calculating a retail price index, putting the cart before the horse.

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A good read

William Sitwell’s book Eggs or Anarchy tells of the logistical struggle to feed the UK during the second world war. Its quality lies in the author’s insight into the interplay of power, politics and military muscle. Verging on understatement, Sitwell’s account of a gargantuan effort to achieve the almost impossible.

Among the illustrations that appear is a map of the world showing the sea routes taken by different wartime food imports, listing the distance travelled by each  commodity. The map once hung in the Minister of Food’s office and carried a stern warning about not wasting food that had travelled so far and was part of the war effort.

A seasoned business man, Frederick Marquis was elevated to the House of Lords, taking the title Lord Woolton. He was appointed food minister by Neville Chamberlain. Retained by Winston Churchill, Woolton worked tirelessly to overcome the ever steeper challenges that he faced in office. His lack of experience in political life was both a hindrance and a blessing in disguise, giving him the freedom to pursue policy targets without compromising political goodwill.

Woolton demonstrates the complexity of real world logistics and how political considerations can deflect attention from operational necessities.

Eggs by rail
pic Bo Jess om, Wikimedia Commons

The common sense, sturdy construction of this wooden egg crate and thousands like it ensured that once the eggs had been wrapped with a layer of crepe paper, they were good for journeys across Europe. France, Holland and Denmark all exported eggs to England in the latter half of the 19th century and on into the 20th.

Eggsistential threat

When the second world war broke out in 1939, nobody would have imagined that the ministry of food would disappear off the map. Stranger still was the process by which the ministry morphed and started to manage the nation’s food procurement arrangements from a top secret seaside town in Wales. A narrow strip of sea separates Colwyn Bay from the country’s pivotal international port of Liverpool, routinely a target for German air raids.

Had this been known to the Luftwaffe, the British food procurement system would have been destroyed in a matter of days and European history would have taken a very different course. At the time it was a well-kept secret, today the story is told by William Sitwell, in his book Eggs Or Anarchy. http:williamsitwell.com/books

The book traces the challenges that faced food minister Lord Woolton, who applied the lessons he learnt in the world of business to a series of desperate logistical impasses. These were complicated by the antipathy of a less than enthusiastic civil service with its procedural agenda.

Conventional economics makes no allowance for the inherent costs that are part and parcel of animal products. Every egg producer faces regular bills as part of raising chickens, regardless of whether or not they are in lay. If the birds are to live, let alone lay eggs, feed bills are non-negotiable.

For most of the egg-buying public, this upstream reality is literally history. Without an idea of the real world implications, an egg is no more than a disembodied food ingredient. Its price is more complex than than any monetary value that might be assigned to it. In one context it can be priceless, when it is part of a cohort destined for breeding the next generation. This is also the start and the end of humanity’s grasp of the forces of nature.

What “by numbers” is about

Across this website, readers will have seen posts such as butter by numbers or cheese by numbers. The purpose is not spelt out in these posts, so here is the thinking behind the “by numbers” coverage.

First, most of the figures cited go back to the end of the 20th century and are volume measurements. The choice of tonnages over the more usual measurement of currency is intended to give an idea of the additional capacity that imports generate for their economies.

In its simplest terms, importing food occupies production capacity the exporting country cannot use for the local economy. For countries like New Zealand, rural populations are so sparse and urban populations are so far apart that this is  not a problem.

Market gardeners close to urban centres in countries such as Kenya, on the other hand, can find themselves left with crops of green beans for which they have no local outlet. Having promised to grow premium vegetables for affluent industrial economies, there is no wriggle room for producers if  retail customers change their minds.

By looking at tonnages, it becomes possible to calculate the agricultural resources that are occupied by export production.

The use of data going back to the late 1990s is a reflection of the fact that multiple retailers invested heavily in electronic point of sale and data management for food sales during the early 1990s. The later years of the 1990s mark the moment that the results started to become visible.

Butter by numbers

A cow producing 5000 litres of milk in a lactation (a lot by the standards of the 1990s) would give enough cream for two and a half tonnes of butter. Converting the remaining output into skim milk powder (SMP) would add a further couple of tonnes of powdered milk to the final output. There are other ways of splitting up milk fractions, some of them with limited use and application. Some standard variables appear in the first table, while the second outlines UK butter import tonnages for packet butter (retail product) and bulk butter for 1996-8, when the Common Agricultural policy was in full swing.

Taking the 1998 total packet butter imports total of just over 20,000 tonnes and when the total is divided by 2.5 (tonnes per lactation) it becomes clear that you will need at least 8,000 lactations — or lactating cows — to generate this tonnage. Bulk butter imports for that year topped 66,000 tonnes, needing a further 24,000 cows. Figures on this scale pose two serious questions.

First, is the UK economy capable of generating sufficient demand to increase domestic production by a comparable tonnage? Second, where would the UK accommodate an additional 30,000 dairy cows and the same number of calves that would trigger the necessary lactations? The chances are that the UK economy is not vigorous enough to generate investments in domestic production on that sort of scale. It is equally probable that the UK landscape would not absorb thousands of additional cattle and their calves.

The attraction of imported stock such as bulk butter is that it can be diverted into seasonal products like mince pies, which are planned into shifts after Easter and stored in a freezer until needed in the run-up to Christmas. Energy prices have made this pattern uneconomic this year, but it was a successful venture in previous years.

Butter comprises 80% cream and is transported in a refrigerated system. If there is no refrigeration, butter can be clarified. The process removes the water and heat sensitive protein, turning it into ghee. This can be kept in hot climates at ambient temperatures.

Milk by numbers

Milk is around 90% water, so it makes sense to stabilise it as butter or cheese or milk powder before trying to move it anywhere. A good example would be New Zealand, which has a network of butter/skim milk powder plants, where milk is centrifuged to extract the cream. This is made into butter, while the remaining skimmed milk goes to a drying tower and leaves as skim milk powder (SMP).

The UK has a tradition of marketing its milk as liquid milk, which is either pasteurised, sterilised or put through an Ultrahigh Heat Treatment (UHT) line. UHT cartons will have a life of around a year at ambient temperatures, sterilised milk should be protected from the light, but will last indefinitely in unopened bottles.

Using a centrifuge, milk for pasteurisation or UHT lines will be standardised at 4% or 2% or zero percent for full cream; semi-skim or skim respectively. Surplus cream is usually collected in a tank for sale on the industrial market. A milk packing plant can quite easily generate a tanker load during the course of a week, for most of the year, with the exception of a Christmas peak in UK sales of cream. Before Brexit, tanker loads would often travel as far as Germany and be a viable proposition.

See Butter by numbers.

See Cheese by numbers

Milk powder footnote

All milk for powder making must be centrifuged before it goes through the drying tower. Any remaining cream or protein would block the fine nozzles used to spray the milk into a rising column of hot air. The fat-free Skim Milk Powder is collected from the bottom of the tower.The fat content is restored if there is a need for Whole Milk Powder or a custom formulation for food manufacture or baby foods.

Cheese by numbers

When you come to realise that milk is made up of water — 90 percent or more — it becomes clear that it needs to be turned into something a bit more user-friendly to be transportable. Making cheese has routinely been a convenient way of stabilising fragile milk and preparing it for a longer journey to its end user. Milk proteins will be retained and a proportion of the cream will be either removed or additional cream will be added, depending on the recipe. Cheddaring cheese is basically a technique for extending the working life of milk, using the existing solids. The progression is laid out in the table below.

Having made curd with the milk, there is inevitably some loss of the finely divided protein particles that are retained in the whey. The whey was traditionally fed to pigs, which is why the history of livestock farming in Denmark was so closely integrated. A significant component of Danish bacon in the nineteenth and twentieth centuries started out as whey from cheesemaking.

Depending on the density of grazing livestock — the example here assumes 20 lactating cows to the hectare — there will always be a certain amount of agricultural land that will be blocked from local use by the commitment to export the production it supports. This is a topic to which we will return. For now, it is sufficient to assume that dairy producers will need three lactations (integer values) for every tonne of milk solids that are recovered and transferred into cheesemaking. In addition, there will be a need for three twentieths of a hectare of grazing land to meet the Livestock Unit level in this model.

There is a greater diversity among cheeses, reflecting their moisture content and how the whey is removed during the cheesemaking process. As a cheese ages, it will go from being a crumbly wet curd and solidify into increasingly dense cheeses. Whole cheeses are matured for up to two years in the case of hard cheeses like parmesan or Grana Padana, a year or more for mature grades of Cheddar, to just six weeks for soft cheesses like Camembert or Brie. The protein can be more or less elastic, depending on how much heat has been applied to the curd and other factors in the process.