Sweet chestnuts are generally in season from October, with their peak period in December, which is why there is such a strong association between chestnuts and Christmas.
Sweet chestnuts are the only nuts which are a rich source of vitamin C. They also contain vitamin B, and minerals including magnesium, potassium, and iron.
The Sweet chestnut, Castanea sativa, belongs to the same family as oak and beech and is a large, fast-growing tree, capable of reaching 30m (98ft) in height when mature. Laden with pollen-filled, yellow catkins in early summer, it has long, glossy green leaves with pointed tips and serrated edges with around 20 pairs of prominent parallel veins. In autumn, the leaves turn gloriously golden before falling.
It is the distinctive, deeply grooved bark that twists in a spiral around the stout trunk which make a sweet chestnut tree easy to identify. The trees can live for up to 700 years so they make a gigantic, historical impact on the landscape.
Sweet chestnut trees are vigorous and will grow well in any well-drained soil, being very drought-tolerant once established. They are hardy, but can struggle to produce a good crop of nuts in Scotland unless the summer is hot and sunny.
After pollination, female flowers develop into shiny, red-brown fruits wrapped in a spiky green casing. The trees begin to bear fruit when they are around 25 years old so you have to play the long game with sweet chestnut trees.
Prise off this protective casing and check that the nuts are shiny red-brown in colour, that they feel firm to the touch, and have not already been nibbled. There will be three nuts inside every casing, with the middle one having a flatter shape than the two on either side.
Roasted sweet chestnuts are tasty and nutritious, but many buy them from shops, imported from Italy or Spain, where the additional warmth in the climate allows them to ripen properly.
If you buy sweet chestnuts, you may get the opportunity to choose between castagne and marroni. Marroni nuts are the more expensive of the two, being a larger, rounder, sweeter form of chestnut, with just one nut inside every casing.
Chestnuts can be soaked before roasting to soften the shells slightly for peeling, but it is not strictly necessary. However, If you have foraged for them yourself, be sure to give them a good soak to clean them off.
Score a cross in each casing, right through the brown shell, to stop the nuts from exploding when they are cooking. As the nut heats up, the water inside turns to steam and without an escape hole, it may explode.
Add a single layer of chestnuts in the pan or skillet for roasting, if you stack them they will not all get the heat needed to cook properly.
They will need around 20 minutes to cook properly, shaking the pan every 5 minutes or so to turn the chestnuts. You will know that they are done when they start to look a little burnt on the outside and the shell at the ‘X’ shape starts to peel open a little, revealing a yellowy nut inside.
Properly cooked chestnuts are deliciously buttery and earthy, white undercooked ones taste bitter.
Wait until the chestnut is cool enough to handle before peeling as it will be scorching when it comes off the heat. The warmer it is though, the easier it will be to peel off the shell and the pellicle (the papery thin skin that covers the nut).
Roll greaseproof paper into a cone to serve these tasty treats. For extra protection against the heat, wrap a napkin around the paper cone. You can add a sprinkle of salt if desired, or make a seasonal dip for your sweet chestnuts by heating butter with a pinch each of nutmeg, cinnamon, and sugar.
The Romans reputedly introduced this tree into Britain to produce the nuts which were ground up and made into polenta.
The sweet chestnut became a popular tree with the owners of large estates, and was made particularly popular in Scotland by Mary Queen of Scots. It was very fashionable for the owners of large houses in the early 17th century to plant one.
The Dunipace Sweet Chestnut Tree is one of the oldest and largest of its kind in Scotland. It has a girth of over 8.5m (28ft), and it could be as much as 400 years old, being all that remains of Herbertshire Castle and the once grand estate that dominated the area.
The Cockairnie Sweet Chestnut Tree in the grounds of Cockairnie House, near Arbedour in Fife is said to be the stoutest of its species in Scotland at 8.82m (29ft) round. It is also said to produce the sweetest chestnuts in Scotland. Cockairnie House is about 500 years old and the Woodland Trust believes the tree was probably planted shortly after the house was built.
The tree with the oldest recorded planting date in Scotland is the sweet chestnut at Castle Leod, Strathpeffer, Ross-shire. It is said to have been planted in 1550 for Mary Queen of Scot’s mother, Mary of Guise.
The Queen Mary's Tree in North Lanarkshire is reputed to have been planted by Mary Queen of Scots in 1561 during a visit to Cumbernauld Castle. Although the castle no longer exists, the ancient sweet chestnut survives. It is also thought she planted the Balermino Sweet Chestnut, when she visited the abbey in 1565.
So whether roasting or rambling past, be sure to appreciate the sweet chestnut this Christmas.