Urban Food Chains

the links between diet and power

Autoclaves and retorts

Autoclave and retort are two names for pressure cooking vessels used in food manufacturing to sterilise canned food and in later versions by engineering firms to cure rubber tyres. The starting point was known as a steam digester, attributed to French scientist Denis Papin, in 1679.

The hazards of working with steam under pressure very quickly became apparent and Papin devised a safety valve to mitigate the risk of explosion, leading many to refer to it as the Papin digester. It was called a digester because it was generally used to apply heat and pressure to bones, leaving cooked bones soft and friable for bonemeal. Other processes were developed for this piece of equipment, from which Papin developed a prototype steam engine. This was subsequently developed into the static steam engines built by Thomas Newcomen.

Chevalier-Appert, a nephew of Nicolas, invented the first reliable pressure gauge for retorts and autoclaves in 1852. This was an essential accessory to prevent explosions and standardise the process. Early retorts comprised a steel vessel, with a metal basket to hold filled bottles or cans. Later versions were fitted with systems that allowed product to be rotated as it cooked, reducing the cooking time. To start a cooking cycle, the vessel is loaded and the door closed. Steam is brought into the cooking chamber and the contents cooked for the required time at the necessary temperature. Once cooked, the steam was turned off and the retort allowed to cool.

A cooking cycle can last for hours, not finishing until the centre of the load had been subjected to a predetermined temperature and for a set period of time. The result is overcooked product on the outside to be sure that the centre cooked properly. Later refinements include automated loading, a key advance to raising throughput.

The Shaka principle

The next milestone, in the late twentieth century, was reached by Richard Walden, a process engineer working for Carnaud-Metalbox. Convinced that it was time to make retorts more efficient, he devised what is now referred to as the Shaka retort, which shakes its load backwards and forwards, driven by a reciprocating actuator at speeds of more than 100 cycles per minute.

Richard Walden

It was clear from the outset that when the prototype reached a certain speed, the load underwent a quantum cooking effect, a “sonic boom” for food, so to speak. Depending on the consistency of the product, cooking time went down dramatically. Further details are available here: https://shakaprocess.wordpress.com/what-is-the-shaka-process/

Walden fixed the amplitude on the prototype at around 150mm and varied the speed or rpm on reciprocating arm. For any given product viscosity, Walden could identify a threshold at which a quantum heat transfer took place in the cooking vessel. Further increases in the rpm had no significant effect on cooking times.

John Emanuel signed up manufacturers

Shaka is an undisputed milestone achievement, but has yet to persuade mainstream food manufacturers to scale down their investments in energy-hungry retort lines. The technology has been licensed to two retort manufacturers, Steriflow in France and Allpax in the USA. Prototype, pilot and production models are all available. Although the Shaka units are smaller than their conventional counterparts, they can achieve the same throughput with multiple shorter cooking cycles.

Worst of both worlds for UK farmers

UK farmers exporting to Europe have faced the full cost of third country status from the start, while EU exporters of animal products to the UK have effectively had a free ride in the absence of routine food safety checks on animal products arriving in the UK.

“For the past three years, our farmers have faced the full reach of EU controls on our exports while the EU has enjoyed continued easy access to the UK marketplace,” NFU president Minette Batters told Urban Food Chains. “This is not just an issue for competitiveness, with British farmers faced with additional costs and paperwork, but also for our nation’s biosecurity.”

Pic: NFU

“Proportionate and effective controls are necessary if we are to prevent outbreaks of pests and diseases that threaten human, animal and plant health, the safety, quality and biosecurity of our food products and the confidence of our trading partners.”

More detail on this paradox can be found here.

“It is vital that the government uses the latest delay wisely to raise awareness among EU exporters and to address the concerns expressed by many in the supply chain. This includes horticulture growers who continue to see the shift of controls away from their business premises to border control posts as a major point of jeopardy, with unknown costs and heightened biosecurity risks. This time should also be used to minimise unnecessary delays at the border once the new system is finally up and running.”

Restoring checks on animal products will push up import costs

The UK is at last preparing to complete the Brexit process. For two years randomised routine physical checks on imported animal products have not been carried out. In 2024, ports with Border Inspection Posts (BIPs) will start to undertake physical inspections. These will be comparable to those which have been carried out routinely at European BIPs from day one.

Checks on the documentation for inbound goods, however, is carried at the border. For inbound consignments of animal products, this is done at a BIP, for which an appointment is made. The resources and staff for these checks are charged to the owner* of the goods and amount to just under a tenner a tonne. The cost of physical checks will reflect the degree of sophistication involved, and will routinely come to hundreds of pounds.

The money charged for all this checking is not customs duty but it will be counted towards the customs valuation, an aggregate figure upon which 20% import VAT is due. Local authorities will collect the product checking revenue, HMRC will bank the VAT. Bringing in a full regime of product checking will add significantly to the cost of putting food on the market.

The UK government estimates that the additional fees for product checking and related services will add GBP 330 million a year across all imports from EU. The UK government claims that the impact on food and drink imported from the EU “… will not be significant.” This is a moot point.

Checking the documents for a consignment of animal products in normal office hours would cost GBP 196 at the BIP in East Midlands airport. A further GBP 64 would be charged for goods listed on additional veterinary certificates appearing on the same header document. Costs rise for out of hours inspections, for which prices are quoted on application. Bear in mind, however, that air freight consignments will be smaller than loads packed in containers.

Third country goods going into the EU face physical checks determined by the sampling rate fixed by the customs service. Traders shipping goods into the EU can earn a reduction in the frequency of physical checks, by complying with EU requirements. Think of it as time off for good behaviour. As a new third country, the UK has faced 100% sampling. UK exporters have been charged accordingly, unlike traders shipping to the UK.

*Ownership of goods in transit is a moveable feast. It is often transferred directly from the seller to the buyer when the goods are loaded on to a ship, but since the buyer may not be the end user at this point, there are a number of alternative outcomes. The shipping line often takes ownership for the duration of the journey, since owners can be required to make snap decisions in the event of accidents or mishaps.

Measuring progress

On Your Farm presenter Charlotte Smith and Archers’ actor Lucy Speed open the programme from the middle of Devon by explaining that they are looking for a farm but are surrounded by large sheds and outwardly industrial structures. Somewhere in this seemingly inappropriate setting, they are expecting to meet Andy Gray, a possible finalist for one of the programme’s annual awards.

Andy’s business bridges the gap between livestock farmers and end users of meat. He operates the large food grade cutting and packing lines that they saw on arrival. As well as selling dog food, he also farms 150 hectares of arable crops, as well as keeping a herd of deer and a herd of cattle. Other business activities in his eclectic business include a quarry for heritage building stone.

During the visit, the conversation turns to remedial best practice for soil and the new funding schemes for English farming, based on the provision of a public good such as healthy soil. Rothamstead soil scientist Andy Neil is on hand to discuss some of the vital detail. Charlotte Smith is impressed that Andy should have engaged a Rothamstead professional to measure the recovery of former arable fields. Andy, on the other hand is pragmatic: if he can’t quantify the improvements he is making on his land, he won’t get any government cash. Gotcha.

Customs checks to cost importers 330m gbp

After putting off the implementation of full customs checks five times for imported goods arriving in the UK, Westminster will start enforcing its post-Brexit customs regime for all imported goods in 2024. Cabinet Office minister of state, Lucy Neville-Rolfe, told MPs that the fully operational customs system would cost UK businesses an additional GBP330 million a year. About half this increase will be absorbed by veterinary paperwork, which was not demanded on day one of Brexit. The full cost of becoming a third country has effectively been concealed from the British public for five years and was only revealed on the eve of the Conservative party conference with a full and controversial agenda. https://www.theguardian.com/business/2023/oct/01/uk-admits-extra-330m-a-year-charges-post-brexit-food-imports