Roasting chestnuts: Martaínha & Portuguese tradition
In Portugal, the scent on the street corner tells you it's November. Castanhas assadas – roasted chestnuts – from a black drum over embers, with coarse salt, fifty cents a bag, hand warming included. In Switzerland, we call them "Maroni," the drum usually stands in front of the train station, and the bag costs five francs (inflation, I know). But the real issue isn't the price. It's that most people fail at roasting chestnuts at home: too dry, hard to peel, tasteless. The reason is almost always the same: old chestnuts from the supermarket that have been sitting for weeks. Freshness is everything when roasting. Let me explain why – and why a fresh Martaínha chestnut from Sernancelhe, harvested in autumn, makes all the difference.
What is a Martaínha chestnut – and how does it differ from the regular Maroni?
Martaínha is a Portuguese sweet chestnut variety from the Sernancelhe region (Beira Alta, central highlands). It is one of about ten varieties protected under the DOP Castanha dos Soutos da Lapa. Three things that set it apart:
- It is sweeter. Higher sugar content than most regular Maroni varieties. It caramelizes beautifully when roasted.
- It peels easily. The two skins (the hard outer shell and the thin brown inner skin, episperma) almost peel off by themselves when roasted. That's the big difference – anyone who has eaten an unpeeled Maroni knows what I mean (bitter, leathery, no fun).
- It is large and shiny. Beautiful light brown shell, a bit of a glossy sheen.This is not just for the eyes – large chestnuts roast more evenly.
DOP – why it's on the bag
DOP means Denominação de Origem Protegida (the EU sister of AOP/AOC). The name "Castanha dos Soutos da Lapa DOP" can only be used if the chestnuts come from a clearly defined region, are from certified varieties, and are harvested using specified methods. In Portugal, there are four chestnut DOPs: Soutos da Lapa (Beira Alta, Martaínha and Longal), Padrela (Trás-os-Montes, main variety Judia), Terra Fria (Trás-os-Montes, 10 varieties including Martaínha) and Marvão (Alto Alentejo). An anonymous "supermarket chestnut" can be anything – a Castanha Martaínha from Sernancelhe is exactly one thing.
Freshness is Everything
In our showroom, you can get the Martaínha as Castanha Martaínha in 1, 3, or 5-kilo bags (from CHF 10), 100% Portuguese, gluten-free. We source them directly from Soutos da Vila, a cooperative in Sernancelhe that has been cultivating the ancient Martaínha trees for decades. Harvesting takes place in September/October – what you order from us in the fall was still on the tree just a few weeks prior. Learn more about the botany and history in the first chestnut article.
What is Magusto – and why does Portugal smell like chestnuts everywhere in November?
Magusto is the Portuguese chestnut festival. The name likely comes from the Latin magnus ustus – "great fire". Tradition: From November 1st (All Saints' Day) to 11.In November (São Martinho, Saint Martin), a fire is lit in villages and towns, chestnuts are thrown in, and young wine or Jeropiga – a sweet, fortified wine made from fresh must and brandy – is enjoyed.
The old saying goes: «No dia de S. Martinho, lume, castanhas e vinho.» On St. Martin's Day: fire, chestnuts, and wine. Period. That's basically the whole concept – and honestly, one of the better concepts Portugal has ever had.
In Switzerland, we try to replicate this every autumn in Oberbuchsiten, with varying weather success. If you want to join: simply register in the showroom, a date is always set on the website in October/November.
Why do you always have to score chestnuts – and how exactly?
If you throw chestnuts into the oven without a cut, the same thing happens as with popcorn without patience: they explode.Inside is strength and water; when heated, steam builds up, and eventually, the shell gives way. Sounds funny, but it's not – I once cleaned an oven after "I just took a break." Never again.
So: Serrated knife (tomato knife, bread knife, as long as it's serrated). That's the crucial point – the hard chestnut shell is smooth and round, a regular sharp knife slips off, and you end up with the blade in your thumb. The serrations grip, you need hardly any pressure. In our showroom, there's always one ready to hand. Whether you roast in the oven, in the pan, or over the fire – the tool is always the same.
Score crosswise into the round (convex) side. Important: not only cut through the hard outer shell but also the brown inner skin. Otherwise, the skin won't come off later.If you're in a hurry, make a straight cut instead of a cross – it works too, but is less appealing for peeling.
Pro tip from Portugal: soak the scored chestnuts in lukewarm water for 20 to 30 minutes. This allows the inside to absorb moisture, stay juicy when roasting, and the shells are even easier to peel.
How to roast chestnuts properly – in the oven, in the pan, or over the fire?
Three methods, three results, all good. What they have in common: scored chestnuts and a generous amount of coarse cooking salt. What sets them apart is effort and smokiness.
In the oven (the simplest option)
For most at home, the best method. Always works, requires no special equipment.
- Preheat the oven to 200 °C top/bottom heat.
- Score chestnuts with a serrated knife (see above). Optional: Soak for 20 minutes, then drain.
- Place on a baking sheet with parchment paper, cut side up, do not stack.
- Generously sprinkle coarse cooking salt over them – an honest pinch per chestnut. The salt seeps into the open shell during roasting, seasoning the inside and giving the shell a typical light crust.
- Place a small ovenproof dish with water alongside. This keeps the chestnuts juicy inside.
- Roast for 20 to 25 minutes, depending on size. They are done when the shells open significantly at the cuts and turn brown.
- Immediately wrap in a kitchen towel, let steam for five minutes. Then peel while they are hot.
In the cast iron pan (closer to the street stand)
If you want the street effect – small black spots, smoky flavor – the pan is the way to go. Requirement: cast iron pan with lid. You'll discard a Teflon pan afterward.
- Heat the pan dry on medium heat (no oil, no fat).
- Add scored chestnuts, one layer, do not stack.
- Sprinkle one to two tablespoons of coarse cooking salt over them. The salt partially burns and gives the shell its characteristic white color.
- Put the lid on, heat to low-medium, shake every 3 to 4 minutes. Do not stir – shake.
- After 20 to 30 minutes they are ready. Shells open at the cuts, some dark, others whitish crusted.
Taste: more intense than in the oven, because the direct contact heat creates more roasting substances (Maillard reaction).
Over an open fire (the Magusto variant)
For romantics and garden owners. Authentically Portuguese, tastes best.
- Make a fire, let it burn down to glowing charcoal (no more flames).
- Special chestnut pan (with perforated bottom) or cast iron pan without lid.
- Scored chestnuts, generously salted, directly over the embers, about 10 to 15 cm distance.
- Keep shaking. Really keep shaking. From "perfect" to "charcoal costume" is two minutes.
- After 15 to 20 minutes, the shells are darkly charred, the inside is cooked.
The traditional trick: pour a splash of red wine or water over the chestnuts shortly before the end.The hissing releases steam, the shells pop open, peeling becomes child's play. Doesn't work indoors, understood.
Why are chestnuts from street stands often white on the outside?
This is one of the facts that even die-hard chestnut lovers don't know – and I was about thirty years old when I first understood it. The typical light, almost white color on the shell of street stand chestnuts doesn't come from flour, not from ash, not from a secret coating. It is burnt cooking salt. In the chestnut oven, the chestnuts are roasted together with a generous handful of coarse cooking salt. At high temperatures, part of the salt burns and deposits as a white crust on the shell. Functionally, it's like a dry bath: the salt draws moisture from the outside, the shell becomes drier and peels off more easily.Whoever wants to recreate this at home simply adds coarse cooking salt during roasting – it won't be quite as white, but the effect is there.
How to properly peel and store chestnuts?
Peeling without burning your fingers
Many fail here. Three tricks: First, peel while the chestnuts are hot – once they cool down, the inner skin sticks. Second, wrap them immediately after roasting in a thick kitchen towel and let them steam for 5 minutes; the steam loosens the inner skin. Third, use two towels – one for holding (against the heat), one for wiping. Place the chestnut on the hollow of your hand, flip the shell away with your thumb, done.
If peeling is still difficult, the chestnut was either not scored enough, not hot enough, or simply not a Martaínha. With a good variety, the skin practically slides off on its own.
Storing Raw Chestnuts
Raw chestnuts are like fresh mushrooms: high water content, short shelf life. Two important rules: dry and cool, but not in plastic (plastic leads to condensation, condensation to mold). Use a linen bag, cardboard box, or open bowl in the refrigerator. And the water test: Place chestnuts in a bowl of cold water. Those that float are empty or spoiled – discard them. Stored this way, they last about two weeks. For longer storage: blanch (5 min. in boiling water), cool, peel, freeze. Lasts a year.
By the way: If you're in Switzerland for Magusto, make sure to order in time. Our Martaínha chestnuts are seasonal – usually sold out in November/December. Ordering in October makes it easier.
What goes well with roasted chestnuts – besides wine?
If no salt was added during roasting (or too little), be sure to add some – coarse cooking salt, sea salt, or fleur de sel. Not fine table salt: it dissolves and you taste nothing. Otherwise:
- Wine: Traditionally, the young red of the region. Here, a Douro Tinto or a sweet Tawny 10 Anos works excellently.
- Beer: If you want to bring the chestnut note into the beer, there is the Barona Castanha – a Smoked Brown Ale with Castanha de Marvão DOP, the Alentejo chestnut. Slightly smoky, slightly sweet, lightly anise-like.
- Cheese: Comté, Manchego, aged mountain cheese. Sweet chestnuts against salty cheese – hard to beat.
- Sweet: Honey, dark chocolate, a hint of vanilla. Classic Portuguese «castanhas com mel».
What doesn't work: Chestnuts with wheat beer. Tastes like damp sawdust. I tried it, you don't have to.
Frequently Asked Questions about Roasting Chestnuts
Why do chestnuts need to be scored before roasting?
Because steam builds up inside when heated – without a cut, the chestnuts will explode. Score them crosswise on the rounded side, also cutting through the brown inner skin, otherwise the skin won't come off later.
How long do chestnuts need to be roasted?
In the oven at 200 °C for about 20 to 25 minutes, in a cast iron pan for 20 to 30 minutes, over an open fire for 15 to 20 minutes. They are ready when the shells open significantly at the cut marks.
Which chestnut is best for roasting?
A fresh Martaínha from Sernancelhe. It is sweeter than most Marrone varieties, caramelizes when roasted, and is easy to peel thanks to its loose inner skin. Freshness is key – old supermarket chestnuts become dry.
How should raw chestnuts be stored?
Dry and cool, but never in plastic (condensation leads to mold). Use a linen bag or an open bowl in the refrigerator, and they will last about two weeks. For longer storage, blanch them briefly, peel, and freeze – they will last a year.
Where can I buy fresh Portuguese chestnuts in Switzerland?
At Vall'doAido in Oberbuchsiten. The Martaínha is DOP-certified, fresh from the season, and immediately available from Swiss stock (while supplies last). Free shipping within Switzerland for orders over CHF 250.
Where can I buy Portuguese chestnuts in Switzerland?
At Vall'doAido in Oberbuchsiten (Solothurn). We import the Martaínha directly from the cooperative Soutos da Vila in Sernancelhe, DOP-certified, fresh from the season. Stored in the Swiss warehouse, available immediately (while supplies last). Free shipping within Switzerland for orders over CHF 250.
- Fresh Chestnuts: Castanha Martaínha – 1 kg, 3 kg, or 5 kg. From CHF 10.
- Chestnut Beer: Barona Castanha Smoked Brown Ale with Castanha de Marvão DOP.
- Wine pairing: a simple Douro Tinto or a glass of Tawny 10 Anos – both pair perfectly with chestnuts.
If you want to know which wine suits which occasion, you will find a complete overview in the article the five wine regions of Portugal you must know . Spoiler: Beira Interior and Beira Alta are practically neighbors of the chestnuts.
Roasting chestnuts is not rocket science, but they do not forgive bad chestnuts. A fresh Martaínha from Sernancelhe makes the difference between "dry chestnut disappointment" and "why didn't I buy two kilos." Score with a serrated knife, sprinkle with coarse salt, roast, wrap, peel, eat – done. A glass of wine with it, a fire would be nice, an open window suffices. That is Magusto in Switzerland.