How potatoes conquered the world

In fact, no one else had laid eyes on a potato before Spanish conquistadors invaded South America in the 1530s and overthrew the Inca empire. That set in motion a whirlwind that blew potatoes to India, France and beyond. This makes it all the more extraordinary just how ordinary potatoes are these days. Their very names proclaim their rootedness in the right-here, in exactly wherever we are: Ayrshire new potatoes, Idaho russet, Irish cobbler, Darjeeling red round.

Even the Incas viewed the potato as pretty ordinary. An Andean legend from long before the Spanish arrived tells of the ‘Baked Potato Gleaner’, a mythical beggar who encapsulated the tuber’s underdog status.

In Peru the potato had long been a staple, eaten alongside maize, quinoa and a multitude of other vegetables. The growing of maize was important to the Inca state, in part because corn was the key ingredient for the aqha (maize beer) that lubricated many official events. The Inca himself participated every year in a symbolic maize-planting ceremony, to the accompaniment of music and song, and similar state-level festivities marked the maize harvest. In the sacred fields around the Inca capital, Cuzco, small gold and silver replica cornstalks were interspersed among the growing maize, to ‘encourage’ it.

No such imperial oversight was bestowed on potatoes, which were considered a lowly food, necessary but banal. Cultivated at village level, they were traded and consumed within more local orbits, their growth fostered by smaller rituals outside the orbit of the Inca state. One account from 16th-century Peru describes the local festivities that marked the inauguration of the planting season in the mountain village of Lampa. Local dignitaries seated themselves on carpets to watch the proceedings. A procession of richly attired attendants accompanied the seed potatoes, which were carried by six men making music on drums. Events culminated with the sacrifice of a particularly beautiful llama, whose blood was immediately sprinkled on the potatoes.

Potatoes remained an important resource for Andean villagers in subsequent centuries. The 80-year-old Felipe Guaman Poma de Ayala, descendant of Quechua noblemen, drew a picture of a village potato harvest in the early 17th century. His line drawing showed villagers hard at work unearthing and transporting the crop.

The spud goes global

The same forces that brought the conquistador Francisco Pizarro and his soldiers to Peru subsequently propelled the potato around the world. From the 16th century, colonialism, warfare and expanding networks of trade set people and objects in motion in unprecedented ways. The potato was caught up in this global flux. Today, according to the United Nations, it is grown in virtually every country, and is the world’s fourth most important food crop.

The skilled task of adapting the potato to the varied growing conditions it encountered in northern Italy, Bengal or upstate New York was undertaken largely by the anonymous small farmers who grew the new plant in garden plots, and doubtless appreciated the potato’s prolific yield and nutritious content. While a hectare of land sown with wheat may yield enough protein to feed seven people over the course of a year, a hectare of potatoes will nourish 17. Only soybeans produce more protein per hectare, among the major crops.

Potatoes also require less water than other crops, and grow in a great variety of climatic conditions, including on poor soil. The potato is thus an excellent tool in efforts to reduce hunger and food insecurity. This is why the United Nations named 2008 ‘The International Year of the Potato’. Ordinary people doubtless also appreciated the fact that tax collectors were slow to notice the new arrival, and so for many years potatoes did not attract the same tithes and other agricultural taxes levied on more familiar crops.

The potato’s integration into everyday eating practices around the world did not however result solely from the colonial, military and mercantile forces that provided the means for the plant to reach new destinations. Local contexts also shaped its reception.

In New Zealand, where European sailors had planted potatoes in the 1770s, the tubers were quickly adopted into Maori agriculture both as a foodstuff and as a commodity. As a foodstuff they supplemented the local staple of sweet potatoes. Unlike sweet potatoes, which were embedded in a pre-existing web of ritual restrictions on cultivation, potatoes were free of such prohibitions and so could be grown in a wider range of circumstances. The historian Hazel Petrie has suggested that, for this reason, potatoes were a popular addition to village agriculture and quickly became an important food, consumed in huge quantities at the hui, or festive gatherings, that punctuated Maori life.

They also acquired an economic importance. Together with pigs, potatoes were used as a currency when trading with Europeans for muskets and other iron goods. By the early 19th century, Maori farmers were growing the plant on a large commercial scale specifically for this trade. “Potatoes and pork, pork and potatoes wherever we went. I began to get tired of pork and potatoes,” complained one English writer during an 1830s visit to the islands.

European voyages of exploration and colonisation brought the potato to New Zealand but its entry into Maori life resulted from Maoris’ active management of the trading and diplomatic opportunities it enabled, as well as their technical skill in adapting it to the local agricultural context.

The sneering state

Although ordinary people in many parts of the world came to appreciate potatoes, this enthusiasm was not always shared by representatives of the state. In 17th-century Ireland, colonial officials complained that the prolific potato allowed locals to laze around and enjoy life, rather than working hard for the benefit of the occupying English state. “What need they to work, who can content themselves with potatoes?” one English officer, William Petty, remarked testily. Potatoes were derided for being too prolific.

Yet, during the 18th century, such criticism was replaced by approbation. As industry and agriculture expanded and warfare increased, high-yielding, easy-to-grow foods began to look more attractive to statesmen. The potato regained its allure. Patriotic individuals across Europe encouraged potato consumption, and sponsored all manner of competitions and other promotions in the hope of shifting consumers from wheat bread and other grains onto potatoes.

In 1790, Peter Sirkal, a peasant from Lifland (part of the Russian empire), received 10 roubles, enough to buy a horse or perhaps two bulls, when he won a competition sponsored by the St Petersburg Free Economic Society for the largest potato harvest. Four years later, the Tuileries Gardens in Paris were dug up, replaced with potato fields planted on the orders of the national government, which likewise hoped to encourage wider cultivation of the root. Increasing potato consumption became a goal for many European states during the Enlightenment.

In the 18th century, as expanding industry increased the need for robust workers, the nutritious potato gained a new allure

But with the coming of a new century, the potato’s fortunes swung yet again. Pessimism about the potato’s capacity to contribute to economic growth and national security returned during the Victorian era. With growing industrialisation came an obsession with nutritional science as the key to unlocking economic growth. ‘Human motors’ – the working bodies who powered factories – needed sufficient protein and other nutrients in order to ensure commercial success. Nineteenth-century nutritionists were not enthusiastic about potatoes. Sadly, they were believed to encourage ‘lazy potato blood’ and a sluggish personality. A mere 14 days of subsisting on the tuber would render a man unable to work at all, in the view of the Dutch physician Jacob Moleschott.

Worse, potatoes were now associated with backwardness. In demonstrations of the potato’s negative effect on the advance toward modernity, the Irish peasant was – as he had been two centuries earlier – Exhibit A. Because they subsisted on potatoes that they grew themselves, Irish cottiers could resist becoming a rural proletariat wholly dependent on wages for their survival. From this perspective, potatoes were a roadblock on the route to capitalism.

This viewpoint would have terrible consequences. Many of the 19th-century liberals in Whitehall who ran colonial Ireland viewed the terrible potato famine that decimated the country between 1845 and 1849 as a blessing, because it promised to wipe out a way of life they viewed as archaic. How, asked Charles Trevelyan, assistant secretary to Her Majesty’s Treasury, were Irish labourers to support themselves in the post-famine future? He saw only one possibility: “The position occupied by these classes is no longer tenable and it is necessary for them to live by the wages of their labour.” The Irish would no longer eat potatoes that they grew themselves, but rather grain, “which they will purchase out of their wages”. In other words, they would become a rural proletariat.

While, in the 17th century, writers such as Petty disliked the potato because it enabled Irish peasants to evade the reach of the state, by the 19th century its crime was to defy the inevitable advance of capitalism.

Expert opinion about the potato’s contributions to building powerful economies and strong states has continued to oscillate between enthusiasm and disdain. During both world wars, potatoes were enlisted in the war effort, often in the hope of protecting scarce grain supplies.

In the First World War, the US government hoped increased domestic potato consumption would compensate for the export of 20 million bushels of wheat destined for allies in Europe. Potatoes featured regularly in the flourless wartime ‘victory recipes’ distributed by the new Food Administration.

A battalion of potatoes brandished sabres and waved the stars and stripes under the leadership of General Pershing

The owners of the Staack & Luckiesh pharmacy in the Iowa town of Maquoketa used their shop window (shown above) to present an imaginative staging of such advice. Below a placard exhorting Americans to “Join the ranks and spud the kaiser”, a small battalion of potatoes brandished sabres and waved the stars and stripes under the leadership of a larger potato representing General Pershing, head of the US Expeditionary Forces in Europe. An explanatory label hailed the formation of “the newest fighting corps: the Potatriots”. “Eat potatoes and save wheat” was the overall message, proclaimed clearly on a placard. Suitable recipes could be obtained inside the shop.

In contrast, the agricultural development programmes created from 1945 accorded almost no importance to potatoes and other tubers, and focused instead on grains such as maize and rice. From their perspective, the potato was “not relevant” to global food security.

Against the ebb-and-flow of varying governmental attitudes towards the potato, small farmers around the world continue to appreciate the tuber’s many virtues. The United Nations was right to hail the potato as an important source of food security, especially for poor farmers in the global south.

In the UN’s view, the potato contributes to food security because it is widely eaten, and hence is “a truly global food”, because it is nutritious and easy to cultivate, and – crucially – because it is not an internationally traded commodity

Since potato markets are generally local, shoppers are protected from global price fluctuations. Cereal prices, in contrast, have increased markedly since 1990, causing serious hunger in the developing world. Many people grow potatoes for their own consumption, and so can avoid markets altogether. The very qualities that outraged William Petty in the 1670s, and Charles Trevelyan in the 1840s, are now identified as virtues.

Local knowledge

In declaring 2008 the International Year of the Potato, the UN praised the expertise of small-scale potato farmers around the world for protecting the genetic diversity that is now identified as a major component in a sustainable food system. Like trained scientists, small farmers are often experimentalists, engaging in observation, interpretation, field-trials, evaluation and manipulation in order to identify and develop new cultivars and new methods of cultivation. They discuss their experiences with others in their locality, exchange seeds and techniques, and adapt their own practices in light of these conversations.

In the Andes, many potato farmers maintain between 12 and 15 different plots in continuous cultivation; yet more are cultivated non-continuously. They may also swap both seeds and fields with neighbours. Through such exchanges it is possible for a single farmer to gain access to up to a hundred different potato cultivars. Matching particular seed potatoes to the soil and environmental requirements of specific pieces of land requires a vast body of practical agronomic knowledge, and leads to ongoing experimentation.

This sort of constant evaluation and innovation is responsible for the remarkable diversity of potato varieties in the Andes. In the 1960s agronomists thought that Peru possessed some 1,400 native potato varieties; current estimates now put the figure somewhere between 2,700 and 3,800. Today, the global potato provides nourishment to farmers and eaters around the world, including in its Andean homeland.

Rebecca Earle is a professor in the Department of History at the University of Warwick. She is the author of Feeding the People: The Politics of the Potato, which was published by Cambridge University Press in June

This article was first published in the September 2020 edition of BBC History Magazine