Overview

The common walnut (Juglans regia) is a deciduous tree nut native to a broad region from the Balkans through the Himalayas to southwest China. Its kernel has a mild, slightly astringent flavor with a buttery texture and a thin, papery skin. The nut is eaten raw, roasted, or pressed for oil, and is a common ingredient in both sweet and savory dishes across Europe, West Asia, and North America.

Origin and history

Juglans regia is believed to have originated in the mountain ranges of Central Asia, with the largest remaining natural forests found in Kyrgyzstan, particularly around Arslanbob in Jalal-Abad Province [1]. Archaeological evidence suggests the nut was gathered by humans in the Neolithic period, and cultivation spread westward through Greece and Rome, then across Europe [2]. The species was later carried to the Americas by European colonists. The common name “English walnut” is sometimes said to reflect its historical association with English merchant shipping, though the tree is not native to England.

Varieties and aliases

  • Persian walnut (common name in horticultural and historical contexts)
  • English walnut (common name in North America)
  • Common walnut (common name in Great Britain)
  • Juglans regia (scientific binomial)

Culinary uses

Walnuts are eaten raw, toasted, or candied, and are a frequent addition to baked goods such as brownies, cakes, and breads. They are a key ingredient in pesto alla genovese (as a substitute for or alongside pine nuts), in walnut oil for dressings, and in the Georgian dish satsivi (walnut sauce for poultry). In Persian cuisine, walnuts appear in fesenjan, a stew of poultry or meat cooked in a pomegranate-walnut sauce. The green, unripe fruit is used in some European traditions to make nocino, a walnut liqueur, and pickled walnuts.

Cross-cuisine context

No widely recognized analogue in Mexican cuisine exists for the common walnut. The native Mexican walnut species (Juglans major and Juglans microcarpa) are smaller and have thicker shells, and are not used in the same culinary manner. In Korean cuisine, walnuts (hodu) are used in hodugwaja (walnut-shaped pastries filled with red bean paste) and in yakgwa (a fried honey cookie), but the species used is typically Juglans regia imported from China or the U.S. In Japanese cuisine, walnuts (kurumi) appear in kurumi-ae (walnut dressing for vegetables) and in confections, again using the same species.

Notes for cooks

  • Walnuts turn rancid more quickly than many other nuts due to their high polyunsaturated fat content. Store in an airtight container in the refrigerator or freezer.
  • The papery skin can be bitter. To reduce bitterness, blanch walnuts in boiling water for one minute, then drain and rub off the skins.
  • When toasting walnuts, watch closely; they burn easily due to their oil content. Toast at 350°F (175°C) for 5 to 8 minutes.