Often the first thing that comes to mind when thinking of chestnuts is Christmas. Have you got the words “chestnuts roasting on an open fire” singing in your head? But, did you know you don’t have to buy them in the supermarket? You can forage your own sweet chestnuts, if you know when and where to look. We’ve made a video all about how to do just that, and you can watch it just below.
Autumn is a perfect time to go foraging for a variety of wild nuts, berries, and fungi. In this blog we’re going to focus on how to find and cook sweet chestnuts, one of our favourite wild foods of the season. You will also learn how to identify the tree they grow on and learn the nutritional benefits of this wild food.
In the UK, sweet chestnuts come into season in October, so if you want them for Christmas you have to be looking well in advance and be ready to freeze them. Finding a ripe chestnut on the forest floor ready for roasting is such a treat and this article will give you the best chance of finding some for yourself. Read on to learn about the history of the sweet chestnut, become an identification expert and learn some delicious recipes to cook at home or over the campfire.
The sweet chestnut hails all the way from Western Asia and was thought to have been introduced into Europe by the Greeks or Romans and used by the military to sustain their troops. The Latin name Castanea is actually derived from the name of a Greek town called Castonis where the tree was heavily cultivated for their nuts. The sweet chestnuts that grow in the UK tend to be smaller and less successful than the ones that grow in mainland Europe due to the cooler climate and in fact most of the chestnuts we buy at Christmas are grown in either Portugal or France. The tree is at the edge of its natural range here, though climate change could make them more favourable to the UK.
How To Identify Ripe Sweet Chestnuts
The spiny casing goes from a lime green to a light brown as the chestnuts ripen, but the best ones will be more green than brown. Unfortunately, many of the largest ripe nuts will be eaten by squirrels before they can hit the ground so it’s important to go foraging early to give yourself the best chance of finding a good batch. Remember to take a thick pair of gardening gloves with you for cracking the casing open, as the spines can make the casing impenetrable and painful to handle. Don’t be disheartened if the chestnuts aren’t as big as the casing would suggest, it’s a little luck of the draw when foraging.
Sweet chestnuts are easy to identify as they’re covered in a soft white fuzz that tufts into a point at the top of the nut. Be careful not to mix them up with horse chestnuts (conkers to you and me) which looks very similar but have far less spines, a glossy shell and are more rounded. Another difference is that there are up to three sweet chestnuts in each case, whereas there is typically only one horse chestnut in each case. If you find a nut out of its casing and you’re not confident in identifying it, you can always look at other clues from the tree itself. So, let’s take a look at the video where I go foraging for nuts…
Now we’ve had a good look at the this tasty wild food, let’s go into a bit more detail about the identifying features of the tree, so that you can be really confident you know what you’re looking at.
How To Identify a Sweet Chestnut Tree
The sweet chestnut (Castanea sativa) is a member of the beech family and can sometimes be confused with the horse chestnut (Aesculus hippocastanum) due to their similarity to the much-loved conker. However, there are some distinct features that set the sweet chestnut apart and will reliably help you identify the tree correctly.
When looking for sweet chestnuts the leaves are the first identifier. They have an elongated ovular shape with a strongly serrated edge. The leaves themselves are one of the largest you will find commonly in the countryside and longer than they are wide, growing up to a huge 28cm long and up to 9cm wide. Another clue that you’re looking at a sweet chestnut are the 20 or so pairs of veins packed closely together running down the central vein. In the spring and summer, the leaves are a thick and glossy green, fading into a mottled amber in autumn before falling off.
You can, of course, look for these distinctive leaves in the forest floor below the tree throughout winter too.
Unlike the stumpy spikes of conker casings, sweet chestnuts are significantly more prickly with sharp barbs protecting the nuts from pilfering wildlife, though they don’t seem to put squirrels off. So, a thick pair of gardening gloves is essential when trying to break them open. The technical term for the spiny casing is cupules and this shell goes from a bright vibrant green to a lighter brown as they begin to mature and decay on the ground. You will start spotting the small, young cupules as early as July.
You can tell when the chestnuts are ripe because the casing will be large and green, heading towards a lighter brown colour. They will begin to split open as they ripen, and you can often see parts of the chestnut through the cracks in the casing as they grow. The cupules typically fall over a two week period around the middle of October and you will often see bits of brown casing around the tree showing the squirrels and mice have been hard at work.
On younger trees the bark is a smooth brown or deep forest green. However older sweet chestnuts develop deep fissures running lengthways up the tree which have a tendency to twist as they grow creating a spiral of fissures around the trunk which is incredibly beautiful and distinctive. Along with the fallen nut cases, this is the most reliable indicator of a mature sweet chestnut, especially going into winter when the trees lose their leaves.
Sweet chestnuts have long light yellow catkins that flower around June, with both the male and female parts growing together on the same tree. A catkin will contain small female flowers at the base, which become the young nut cases once they are pollinated.
If you’d like to know more about how to identify common trees in the British countryside, then you could join the thousands of students already on my FREE online tree identification course, where you can learn through videos, downloadable ID sheets and photo galleries. You can enroll for your free place on the course right here.
How To Cook Sweet Chestnuts
One of the uses utilised by the Romans is using ground roasted chestnuts to make polenta, a traditional Italian food. Today polenta is generally made from boiled cornmeal but there is no reason you couldn’t make your own polenta with chestnuts. To make a sweet chestnut flour you need a large quantity of chestnuts, probably more than you would be able to forage but there is no reason you couldn’t try to make it with shop-bought chestnuts. If you’ve never tried polenta before, it has a porridge-like consistency when hot but can be cooled down into a solid block that can be cubed and fried and goes really well with stews. You can also try using the flour to thicken bread and cakes to give it a naturally sweet edge.
Another favourite is the roasted chestnut at Christmas, if this is something you haven’t tried I would strongly recommend incorporating roasted chestnuts into your Christmas traditions. Sweet, toasted chestnuts are such a seasonal delight, but they don’t have to be eaten just at Christmas. In October you can pick them fresh from the tree and cook them there and then in a pan on the campfire or at home in your oven. Another tradition is to substitute the pan for roasting the nuts on a garden spade. They can also be cooked right in their shells in the embers and ash of an open fire. There’s a lot of fun to be had with this ancient method of simple cooking.
To roast them in an oven, score a cross on the shells and put them in a conventional oven at 200°c for 30 minutes. Once they are cooked leave them to cool for a minute or two before peeling the shells and eating.
There are so many other ways to incorporate sweet chestnuts into your food. Add roasted chestnut chunks into chocolate brownies for added crunch or into stuffing for Sunday lunch. Try tossing roasted chestnuts in a sweet soy sauce glaze for an afternoon snack. The fantastic thing about them is that chestnuts go so well with both sweet and savoury dishes so really the only limit is your imagination.
Marron Glacés; a French Delicacy
Below are instructions on how to make marron glacés, a traditional French recipe for crystallised chestnuts which was popular in the 18th century. They’re a delicious treat that would make for a unique addition to the Christmas table. The chestnuts require soaking over several days so leave plenty of time to prepare them.
You will need:
- 500g fresh peeled sweet chestnuts
- 300ml water
- 500g caster sugar
- 1tsp vanilla extract
- Boil the peeled sweet chestnuts in a pan for 10 minutes then drain the water and with your fingers, or a small clean cloth, peel the thin skin away.
- In another pan bring the vanilla extract, caster sugar and water to a boil to make a syrup. Make sure you stir continually to avoid any burning at the bottom of the pan. Simmer on a medium heat for 5 minutes.
- Stir in the chestnuts and simmer for another 10 minutes. Keep stirring!
- Take off the heat and transfer to a clean bowl and leave covered in a cool place overnight. Don’t put it in the fridge or the syrup will set and take longer to boil the next day. Leave them to soak for a minimum of 12 hours.
- The next day in a fresh pan, bring to the boil and cook for only 2 minutes before taking off the heat and leaving them to soak again for at least another 18 hours.
- Repeat this process three more times (I said you need plenty of time for this one!) until the sugar syrup has been absorbed by the sweet chestnuts.
- Transfer the chestnuts to a tray lined with baking paper and cook at 70°c for 1-2 hours with the oven door opened slightly. Check on them regularly; you want the syrup to harden before removing them.
- Once cooled they are ready to serve. Enjoy!
Good News; Chestnuts Are Good For You Too
Unsurprisingly sweet chestnuts offer a wealth of nutritional benefits, being a rich source of vitamins and minerals. Chestnuts are a source of carbohydrates and proteins; only 100 grams contains a third of your daily required carbohydrate intake and 44% of your daily required vitamin C intake which promotes the production of white blood cells to boost the immune system.
As well as this chestnuts also contain magnesium which helps strengthen enamel on your teeth and calcium and phosphorus which strengthens bones. You can also find your B vitamins in chestnuts which contribute towards keeping your nervous system and skin healthy as well as helping the body break down food, in fact B vitamins 1 through 6 can be found in chestnuts.
You can read a more about the detailed breakdown of the nutritional value of sweet chestnuts in this article by Health Benefits Times.
Get further information about the benefits of B vitamins on the NHS website, right here.
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