The chuño negro, also called papa milenaria, is a product obtained from the transformation of “amargas” potatoes (Solanum juzepczukii and Solanum curtilobum).
Since the time of the Incas these potato varieties have undergone a freezing process, possible thanks to the climatic conditions that characterize the Andes, and are later dried. The major changes in temperature and pressure eliminate the liquid contained in the tubers improving their preservation. In addition. this process helps lower the concentration of glycoalkaloids, responsible for the bitter taste of this potato cultivar.
Different types exist based on the color of the chuño, and the transformation method and duration. In the Peruvian Andes, chuño negro is produced between March and April, after the harvest, while the white version, already present in Arca del Gusto, is made in summer, between July and August.
The bitterest potatoes are used to obtain chuño negro, which are then frozen and dried in the sun.
Once the product is obtained, it has a consistency similar to a freeze dried food with a beige color due to oxidation of some of the substances in the tubers. The high concentration of protein and minerals makes it an essential food in the diet of the people who live in the Andes. Chuño is generally made by families and can be found for sale in local markets.
Chuño negro can be rehydrated and used as an ingredient in soups or stews such as chayro, a soup made from dried lamb meat and vegetables, or turned into flour and used as a thickener for sweets.
This product is also used in traditional medicine to treat gastritis and ulcers. Its uses and consumption are limited to certain mountain areas. Moreover, due to the abandonment of the Andes, bitter potatoes are increasingly rare along with the loss of the knowledge needed to make this product.