The millennia-old potato

The potato has been consumed in Europe for only about five hundred years, although it has been used as a food crop in South America for much longer. It was cultivated in the Andies in South America already thousands of years ago. The wild potato was most likely adopted for food in the area surrounding Lake Titicaca approximately as early as ten thousand years ago. Over time, the Indians started to cultivate seven wild potato species

Gradually, knowledge of the potato and potato seeds spread around South America. By the 16th century, potato cultivation had spread from northern Columbia to southern Chile. Europeans probably had their first encounter with the potato when the Spanish conquistador Francisco Pizarro and his troups defeated the Incas and conquered the region of present Peru in 1532. The first description of the potato was made by Juan de Castillanos, a member of the Spanish expedition that reached the northern Andies a little later, in 1537.

The Spanish conquests and the subsequent battles, diseases and pillagings proved fatal to the native South American Indians living on the slopes of the Andies. The ships returning to Europe were loaded with potatoes, in addition to the treasures of the Indians. The Spanish realised they stayed healthy by eating them on their return journey, and scurvy, caused by vitamin C deficiency, did not affect them. The Canary Islands, where the ships would stop en route, most likely began cultivating potatoes as early as 1562.

The earliest written notes about the potato in Europe date back to 1567: an invoice for a potato and citrus fruit shipment to Antwerp still exists from that year. The first Europearn potato was probably grown in Spain. There are notes about this dating back to at least 1573.

The potato gained popularity for a long time as a speciality in Central European stately homes, castles and gardens. Its cultivation was met with strong opposition, since it was thought that potatoes were the cause of various diseases. It was considered suitable feed for pigs. Frosts would also ruin potatoes before it produced any crops. However, potato cultivation gradually became common, and the growers learned to select varieties better suited to their conditions. Potatoes became a commonly grown crop and a significant source of nutrition in Central Europe at the end of the 18th century.

The potato arrived in Finland along with German tinkers in the 1730s. The tinkers came to work at Fagervik Manor in Inkoo. However, potatoes only became commonplace in Finland after Finnish soldiers fighting in the Pomeranian War between 1757–1762 got to know it in Germany.

The nutritional value of the potato as a common staple was quickly discovered here. It overtook the turnip over time as the most important Finnish breeding and foor crop. The clergy, in particular, would advocate and support potato cultivation. A strong defender of the potato was the chaplain of the Asikkala congregation, Axell Laurell. In 1772 he even compiled a booklet "for Husbandry on Growing, Preserving and Using the Potato or the Earth-Apple". Anders Lizelius, the Vicar of Tyrvää, used to preach about the potato for hours in his church and wrote about it in 1776 in the first Finnish newspaper that he also published, Suomenkieliset Tieto-Sanomat.

The Finnish Economic Society, founded in 1797, also played a significan role in the spread of the potato. The association emphasised the importance of the potato in various contexts. The association estimated in 1807 that potato cultivation was so widely spread that special actions to promote it were only needed in Savonia and Karelia.

The popularity of the potato grew further in Finland when its use in spirit distillery became common. Apothecary Johan Julin from Turku wrote a guide in 1815 on how to distill spirits and make bread from grain and potatoes.
In those days, the potato was highly valued in the Nordic countries, particularly in the winter and spring months when fresh vegetables were hard to come by. The potato also played an important role in the prevention of scurvy. Nowadays, the potato is a staple food served with everyday meals as well as on special occasions.
 

Sources:
Arno Forsius: Perunan historia (History of the Potato)
Wikipedia
Kerstin Olsson: Perunan historia (History of the Potato)