Science blog

Today on World Baking Day, we'll look at two milestones in how bread-baking became an industry in Britain.

The first is Dr. John Dauglish's invention of the "aerated bread" process. This mechanical process did not use yeast to raise the bread, but added high-pressure carbon dioxide to the water used to make it. Dauglish argued that this reduced production time and the labour required, made the raising of the bread more controllable, and allowed an end to hand-kneading, which he considered unhygienic. It also allowed bread to be made more easily from wholemeal flour, which even then was seen as more nutritious. Dauglish patented his process in a series of patents between 1856 and 1865, GB2293/1856, GB2224/1867, GB677/1864, GB3184/1864, and GB1346/1865.

As well as his bread process, Dauglish's company, the Aerated Bread Co., or ABC, became a major tea shop chain in Britain and its colonies. The ABC shops turn up repeatedly in late-nineteenth and early-twentieth century literature. Sometimes they were criticised as corporate and industrial, rather like Starbucks nowadays (for example in T S Eliot's poem "A Cooking Egg"), but they were also considered important to women's liberation, as they did not serve alcohol and were considered a safe place for "respectable" women to socialise without risking their reputation or being subject to male sexual aggression.

Both the baking and catering businesses of ABC disappeared during the early 1980s. The site of the company's main bakery on Camden Street in North London is now occupied by a large supermarket, of interest as a well-known work by the "high-tech" architect Nicholas Grimshaw.

The second major change in industrial baking was the introduction of the so-called "Chorleywood" process, named after the location of the Flour Milling and Baking Research Association in Hertfordshire. This was based on high-speed mixing and the use of flour improvers such as potassium bromate (now banned for use in food) and Vitamin C. It greatly increased the speed of bread-making and allowed bread to be made from low-protein wheat flour that had previously been considered unsuitable for bread-making. Chorleywood bread is the typical supermarket sandwich loaf, soft and long-lasting with even small bubbles in the crumb.

However, the process has been heavily criticised by some traditional bakers, who blame Chorleywood bread for the increased level of coeliac disease and milder gluten intolerance in Britain in recent years. It has been argued that slower fermentation by more traditional yeast and bacterial cultures reduces the quantity of the specific gluten proteins that cause intolerance, and fermentable carbohydrates that may contribute to other bowel problems, although this remains unproven.

Further reading:
Cauvain, C P and Young, L S, The Chorleywood bread process. Boca Raton: CRC Press, 2006. Available at m06/27984.
Costabile, A, et al., Effect of breadmaking process on in vitro gut microbiota parameters in irritable bowel syndrome, PLoS One. 2014, 9(10), e111225. Available free online at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0111225
Edwards, W P (Ed.), The science of bakery products. Cambridge: Royal Society of Chemistry, 2015. Available as a legal deposit e-book in British Library Reading Rooms.
Richardson, B W, On the healthy manufacture of bread: a memoir on the system of Dr. Dauglish. London:Bailliere & Co., 1884
Shaw, G, Curth, L H, and Alexander, A, Creating new spaces of food consumption: the rise of mass catering and the activities of the Aerated Bread Company, in Benson J and Ugolini, L, Ed. Cultures of selling: perspectives on consumption and society since 1700, Aldershot: Ashgate, 2006, pp.81-100. Available at YC. 2006.a.13499
Weichselbaum, E, Does bread cause bloating?, Nutrition Bulletin, 2012, 37, pp.30-36. Available at (P) HP 30-E(2), and online in British Library reading rooms.

Posted by Philip Eagle. Image from "Modern London" by Richard Phillips, 1804.

Sir Henry Bessemer, caricature by "Spy" (Leslie Ward)

On Tuesday evening Philip attended an event at City, University of London, for the unveiling of a blue plaque to the inventor and entrepreneur Sir Henry Bessemer. Bessemer lived for some time in a house at Northampton Square in Islington, in a block that was demolished after World War II for the construction of the university’s current main entrance building. When the main entrance was reconstructed recently, archaeological investigation confirmed that Bessemer’s home had been directly on its site. After the plaque unveiling, Dr. Susan Mossman from the Science Museum delivered a lecture on Bessemer’s life, from which much of the information in this post comes.

Bessemer is best known for his revolutionary process for steel manufacture, by blowing air through molten pig iron in an egg-shaped converter, to oxidise away most of the carbon in the pig iron. This left steel with the correct proportion of carbon to make it a useful metal. The process was covered by several British patents in 1855-6, but especially GB2321/1855 and GB2768/1855. These patents are not online, but you can see digital copies of them if you come to our reading rooms.

Bessemer preferred to licence his patent rather than build an ironworks himself, but many early licensees failed, and the process was considered a flop until he constructed an ironworks in Baxter Road in Saint Pancras, close to where the British Library is now, and began selling steel at far lower prices than anyone else could manage. It turned out that the process as Bessemer first conceived it was not suitable for iron containing high levels of phosphorus impurities, which was true for metal from ore mined in Northern England. One answer was to oxidise away the contaminants, which also destroyed the carbon already in the pig iron, and then add new carbon and manganese. This process was developed by Robert Forester Mushet, whose business failed but whose process Bessemer took over once Mushet’s patent expired. Bessemer was finally, reportedly shamed by Mushet’s daughter, persuaded to give Mushet a pension. The second answer was the Gilchrist-Thomas process, which lined the converter with alkaline stone, causing the acidic phosphorus compounds in the iron to form compounds that precipitated out of the steel and into the slag. With these further refinements Bessemer’s process became licenced worldwide, making Bessemer hugely rich, and did not become completely obsolete until the late twentieth century.

Bessemer Converter at Kelham Island Museum, Sheffield

Bessemer had already come up with many other inventions before his steel process, and would continue to do so afterwards. The most lucrative was his first real success, before steel, a method for making bronze powder for metallic paints on an industrial scale, hugely reducing the cost of a product which had previously been made by hand-grinding by craftworkers in Germany. Bessemer kept the process secret for decades, by ensuring that the machines were kept in four sealed rooms with strictly limited access, and that few people other than himself knew more than one of the four stages of the process. This helped him keep a monopoly much longer than the fourteen years he would have had if he’d patented the process. Bessemer was a shrewd businessman who would only continue working in a field as long as it made money. Once competitors had caught up with him he would move on to something else.

Another of Bessemer’s claims to fame was his early investment in “Parkesine”, the first commercialised artificial plastic, a form of celluloid. The business was a failure due to initial low quality, but remains historically important. At the time of his death, Bessemer was having what would have been the world’s second largest telescope constructed at his estate in Denmark Hill, but it was abandoned when he passed away.

Bessemer's tombstone in West Norwood Cemetery (photograph by Robert Mason, CC0 licence)

Bessemer remains an inspiring figure for modern British inventors, but the story of his steel process also demonstrates some important lessons that dispel some of the romantic ideas of the inventor. Firstly, always be open to taking on the ideas of others instead of believing your own ideas to be perfect and unimprovable. Second, you may well have to start your own business instead of assuming that other people will be falling over themselves to licence your idea. Third, always think about whether an invention will make money, as well as its abstract beauty. And fourth, it helps to have plenty of money to invest before you start!

Further reading:

Patents by Henry Bessemer, in the Business & IP Reading Room at St Pancras.

An earlier blog post by Dr. Mossman on Bessemer’s life.

Bessemer, H and Bessemer, H Jr. Sir Henry Bessemer, FRS: an autobiography. London: Engineering, 1905. Available for order to our Reading Rooms at 10825.k.7 or Wq3/9544.

Bodsworth, C (Ed.). Sir Henry Bessemer: father of the steel industry. London: Institute of Materials, 1998. Available for order to our Reading Rooms at YK.1998.b.6654 or 2247.795000 690.