Sweet chestnut

{{Short description|Species of tree}} {{Lead too short|date=April 2026}} {{Speciesbox | image = Chestnuts.jpg | image_caption = Fruit | genus = Castanea | species = sativa | status = LC | status_system = IUCN3.1 | status_ref = <ref>{{cite iucn |author=Barstow, M. |author2=Khela, S. |year=2018 |title=''Castanea sativa'' |volume=2018 |article-number=e.T202948A67740523 |doi=10.2305/IUCN.UK.2018-1.RLTS.T202948A67740523.en |access-date=17 July 2023}}</ref> | authority = Mill.<ref name="Miller">Miller. Gardeners Dictionary ed. 8 no. 1 (1768). Flora Europaea: [http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Castanea&SPECIES_XREF=sativa&TAXON_NAME_XREF=&RANK= ''Castanea sativa'']</ref> | range_map = Castanea sativa range.svg | range_map_caption = {{Color box|#70A800}} Probable native range <big>'''✖'''</big> Isolated population {{Color box|#FFD37F}} Introduced and naturalised (synanthropic) area <big>'''✖'''</big> Isolated population }}

The '''sweet chestnut''' ('''''Castanea sativa'''''), also known as the '''Spanish chestnut''' or '''European chestnut''', is a species of tree in the family Fagaceae, native to Southern Europe and Anatolia, and widely cultivated in Western and Central Europe. A substantial, long-lived deciduous tree, it produces an edible seed, the chestnut, which has been used in cooking since ancient times.

== Description ==

''Castanea sativa'' attains a height of {{convert|20-35|m|abbr=off|ft|0}} with a trunk often {{convert|2|m|ft|0|abbr=on}} in diameter. Around 20 trees are recorded with diameters over {{Convert|4|m|abbr=on}} including one {{Convert|7.5|m|abbr=on}} in diameter at breast height. A famous ancient tree known as the Hundred Horse Chestnut in Sicily was historically recorded at {{Convert|18|m|abbr=on}} in diameter (although it has split into multiple trunks above ground).<ref>{{Cite web |title=Sweet Chestnuts (''Castanea sativa'') worldwide |url=https://www.monumentaltrees.com/en/world-sweetchestnut/ |access-date=2022-05-26 |website=www.monumentaltrees.com}}</ref> The bark often has a net-shaped (retiform) pattern with deep furrows or fissures running spirally in both directions up the trunk. The trunk is mostly straight with branching starting at low heights. The oblong-lanceolate, boldly toothed leaves are {{convert|15-32|cm|abbr=off|0}} long and {{convert|5-10|cm|abbr=on|0}} broad.<ref name="Mitchell">{{cite book |last=Mitchell |first=Alan F. |title=A field guide to the trees of Britain and northern Europe |publisher=Collins |publication-place=London |date=1974 |isbn=0-00-212035-6 |pages=222–223}}</ref>

The flowers of both sexes are borne in {{convert|10-20|cm|abbr=on|0}} long, upright catkins, the male flowers in the upper part and female flowers in the lower part. In the Northern Hemisphere, they appear in late June to July, and by autumn, the female flowers develop into spiny cupules containing 3–7 brownish nuts that are shed during October. The female flowers eventually form a spiky sheath that deters predators from the seed.<ref name="Kew">Kew Gardens – Rhizotron & Xstrata Treetop Walkway – [https://web.archive.org/web/20080906055951/http://apps.kew.org/trees/?page_id=85 ''Castanea sativa''].</ref> The sweet chestnut is naturally self incompatible, meaning that the plant cannot pollinate itself, making cross-pollination necessary.<ref name=":6">{{Cite book |last1=San-Miguel-Ayanz |first1=Jesús |title=European atlas of forest tree species |last2=Rigo |first2=Danielle de |last3=Caudullo |first3=Giovanni |last4=Durrant |first4=Tracy Houston |last5=Mauri |first5=Achille |year=2016 |isbn=978-92-79-36740-3 |location=Luxembourg |oclc=958294152}}</ref> Some cultivars only produce one large seed per cupule, while others produce up to three seeds.<ref name=":6" /> The nut itself is composed of two skins: an external, shiny brown part, and an internal skin adhering to the fruit. Inside, there is an edible, creamy-white part developed from the cotyledons.<ref name=":6"/>

Sweet chestnut trees live to an age of 500 to 600 years.<ref>{{Cite book |last=Stephan. |first=Hahn |title=Die Esskastanien: Nahrungsquelle und bedrohte Naturressource; ein Beitrag zur Kenntnis der Artenvielfalt |date=2004 |publisher=Books on Demand |isbn=978-3-8334-2192-1 |location=Norderstedt |oclc=76668313}}</ref> In cultivation they may even grow as old as 1,000 years or more.<ref name=":6"/>

<gallery class=center mode=nolines widths=160 heights=160> File:Castanea_sativa_-_Anatolian_sweet_chestnut_04.jpg|Habit File:Castanea_sativa_JPG(C0).jpg|Ancient tree, Corsica File:Castanea sativa MHNT.BOT.2006.0.1272.JPG|Growth rings File:20140316Castanea sativa3.jpg|Twig with bud Castanea sativa A.jpg|Leaves and inflorescences Castanea sativa - Anatolian sweet chestnut, 2018-08-18 03.jpg|Leaves and fruit File:Afgevallen kastanje van een Tamme kastanje (Castanea sativa) 24-10-2021 (d.j.b.) 01.jpg|Fallen fruit </gallery>

== Taxonomy ==

The tree is only distantly related to the horse chestnut ''Aesculus hippocastanum'', which bears superficially similar but inedible seeds (conkers) in a dehiscent seed case (ie. it splits open). Other common names include "Spanish chestnut"<ref>Royal Botanic Garden, Sydney, Australia. [http://www.rbgsyd.nsw.gov.au/welcome_to_bgt/mount_tomah_botanic_garden/the_garden/blooming_calendar/Castanea_sativa blooming calendar]. {{Webarchive|url=https://web.archive.org/web/20091005145141/http://www.rbgsyd.nsw.gov.au/welcome_to_bgt/mount_tomah_botanic_garden/the_garden/blooming_calendar/Castanea_sativa|date=2009-10-05}}.</ref> or "marron" (French for "chestnut"). The generic name ''Castanea'' is the old Latin name for the plant species,<ref>Gledhill, D. 1996. ''The Names of Plants''. Cambridge University Press. {{ISBN|0521366755}}.</ref> while the specific epithet ''sativa'' means "cultivated by humans".<ref name="RHSLG">{{cite book |last=Harrison |first=Lorraine |title=RHS Latin for gardeners |publisher=Mitchell Beazley |year=2012 |isbn=978-1-84533-731-5 |location=United Kingdom |pages=224}}</ref> Some selected varieties are smaller and more compact in growth yielding earlier in life with different ripening time: the Marigoule, the Marisol and the Maraval.<ref>{{Cite web |title=Sweet Chestnut Trees | The Walnut Tree Co. |url=https://www.walnuttrees.co.uk/shop/sweet-chestnut/ |website=www.walnuttrees.co.uk}}</ref>

==Distribution and habitat==

The species is native to Southern Europe and Anatolia. It is found across the Mediterranean region, from the Caspian Sea to the Atlantic Ocean. It is thought to have survived the last ice age in several refuges in Southern Europe, on the southern coast of the Black Sea with a main centre on the southern slope of the Caucasus and in the region of north-western Syria, possibly extending into Lebanon.<ref name=":0">{{Cite journal |last=Conedera |first=Marco |date=July 2004 |title=The Cultivation of ''Castanea sativa'' (Mill.) in Europe, from its origin to its diffusion on a continental scale |url=http://doc.rero.ch/record/319815/files/334_2004_Article_38.pdf |journal=Vegetation History and Archaeobotany |volume=13 |issue=3 |pages=161–179 |doi=10.1007/s00334-004-0038-7 |bibcode=2004VegHA..13..161C |s2cid=55465239}}</ref>

The species is widely distributed throughout Europe, where in 2004 it was grown on {{Convert|2,250,000|ha}} of forest, of which {{Convert|1,780,000|ha|abbr=on}} were mainly cultivated for wood and {{Convert|430,000|ha|abbr=on}} for fruit production. In some European countries, ''C. sativa'' has only been introduced recently, for example in Slovakia or the Netherlands.<ref name=":3">{{Cite journal |last=Conedera |first=Marco |date=2004 |title=Distribution and economic potential of the sweet chestnut (''Castanea sativa'' Mill.) in Europe |url=https://www.researchgate.net/publication/284057112 |journal=Ecologia Mediterranea |volume=30 |issue=2 |pages=179–193 |doi=10.3406/ecmed.2004.1458 |s2cid=126817906 |via=ResearchGate}}</ref>

The tree requires a mild climate and adequate moisture for good growth and a good nut harvest. Its year-growth (but not the rest of the tree)<ref name="PFAF">{{PFAF}}</ref> is sensitive to late spring and early autumn frosts; it is also intolerant of lime. Under forest conditions, it will tolerate moderate shade well.{{cn|date=August 2024}}

== Ecology ==

The leaves provide food for animals including Lepidoptera such as the case-bearer moth ''Coleophora anatipennella'' and the North American rose chafer ''Macrodactylus subspinosus''.

The two major fungal pathogens of the sweet chestnut are the chestnut blight (''Cryphonectria parasitica'') and the ink disease caused by ''Phytophthora cambivora'' and ''P. cinnamomi''.<ref>{{Cite journal|last=Anagnostakis|first=Sandra L.|date=1987|title=Chestnut Blight: The Classical Problem of an Introduced Pathogen|journal=Mycologia|volume=79|issue=1|pages=23–37|doi=10.2307/3807741|jstor=3807741}}</ref><ref name=":17">{{Cite journal|last=Vannini|first=Andrea|date=2001|title=Ink disease in chestnuts: impact on the European chestnut|url=https://www.researchgate.net/publication/228489154|journal=Forest Snow and Landscape Research|volume=76|pages=345–350|via=ResearchGate}}</ref> In North America as well as in Southern Europe ''Cryphonectria parasitica'' destroyed most of the chestnut population in the 20th century. With biological control, the population of the sweet chestnut is not threatened anymore by the chestnut blight and is regenerating.<ref name=":16">{{Cite journal |last=Bounous |first=G. |date=October 2005 |title=The Chestnut: A Multipurpose Resource for the New Millennium |url=https://www.actahort.org/books/693/693_1.htm |journal=Acta Horticulturae |issue=693 |pages=33–40 |doi=10.17660/actahortic.2005.693.1 |issn=0567-7572 |access-date=2018-12-02 |archive-date=2022-02-01 |archive-url=https://web.archive.org/web/20220201093245/https://www.actahort.org/books/693/693_1.htm |url-access=subscription }}</ref><ref>{{Cite journal|last=Anagnostakis|first=Sandra L.|date=1982-01-29|title=Biological Control of Chestnut Blight|journal=Science|language=en|volume=215|issue=4532|pages=466–471|doi=10.1126/science.215.4532.466|issn=0036-8075|pmid=17771259|bibcode=1982Sci...215..466A|s2cid=36933270}}</ref> Ink disease is infesting trees mostly in humid soils, with the mycelium invading the root and resulting in wilting of the leaf. Absence of fruit formation leads to die back of the petal. The ink disease is named after the black exudates at the base of the trunk.<ref name=":17" /> Nowadays there are cultivars that are resistant to the ink disease. ''Phytophthora cambivora'' caused serious damage in Asia and the US, and it still continues to destroy new plantations in Europe.<ref name=":17" />

Another serious pest which is difficult to control is the gall wasp (''Dryocosmus kuriphylus''), introduced in Southern Europe from Asia.<ref name=":16"/>

== Cultivation ==

=== History ===

Pollen data indicates that the first spreading of ''Castanea sativa'' due to human activity started around 2100–2050 B.C. in Anatolia, northeastern Greece and southeastern Bulgaria.<ref name=":1">{{Cite book |last=van Zeist |first=Willem |title=Late Quaternary Vegetation of the Near East |publisher=L. Reichert |year=1991 |isbn=978-3-88226-530-9 |location=Wiesbaden}}</ref> Compared to other crops, the sweet chestnut was probably of relatively minor importance and distributed very heterogeneously throughout these regions.<ref name=":1" /> The first charcoal remains of sweet chestnut only date from around 850–950 B.C., making it very difficult to infer a precise origin history. A newer but more reliable source are the literary works of Ancient Greece, with the richest being Theophrastus's ''Historia plantarum'', written in the third century B.C.<ref name=":0" /> Theophrastus focuses mainly on the use of sweet chestnut wood as timber and charcoal, only mentioning the use of the fruit once when commenting on the digestive difficulties it causes, but praising its nourishing quality.<ref name=":0" /> Several Greek authors wrote about medicinal properties of the sweet chestnut, specifically as a remedy against lacerations of the lips and of the oesophagus.<ref name=":0" />

As with the introduction of grape vine and olive cultivation to the Latin world, the sweet chestnut is thought to have been introduced during the colonisation of the Italian peninsula by the Greeks.<ref>{{Cite book |last=Forni |first=Gaetano |title=Gli albori dell'agricoltura: origine ed evoluzion fino agli etruschi ed italici |publisher=REDA |year=1990 |location=Rome}}</ref> Further clues pointing to this theory can be found in the work of Pliny the Elder, who mentions only Greek colonies in connection with sweet chestnut cultivation.<ref name=":0" /> Today's phylogenetic map of the sweet chestnut, while not fully understood, shows greater genetic similarity between Italian and western Anatolian ''C. sativa'' trees compared to eastern Anatolian specimen, reinforcing these findings.<ref>{{Cite journal |last=Villani |first=Fiorella |date=1990 |title=Genetic structure of ''Castanea sativa'' in Turkey: evidence of a hybrid zone |url=https://art.torvergata.it/handle/2108/43021#.W-7vWDhKipo |journal=Journal of Evolutionary Biology |volume=12 |pages=233–244 |doi=10.1046/j.1420-9101.1999.00033.x |s2cid=84817286 |doi-access=free|url-access=subscription }}</ref> Nonetheless, until the end of the pre-Christian era, the spread and use of the chestnut in Italy remained limited.<ref name=":0" /> Carbonised sweet chestnuts were found in a Roman villa at Torre Annunziata near Naples, destroyed by the eruption of Mount Vesuvius in A.D. 79.<ref>{{Cite journal |last=Meyer |first=Frederick |date=1980 |title=Carbonized food plants of Pompeii, Herculaneum, and the Villa at Torre Annunziata |journal=Economic Botany |volume=34 |issue=4 |pages=401–437 |bibcode=1980EcBot..34..401M |doi=10.1007/BF02858317 |s2cid=22625450}}</ref>

Clues in art and literature indicate a dislike of the sweet chestnut by the Roman aristocracy.<ref name=":0" /> Like Theophrastus, Latin authors are sceptical of the sweet chestnut as a fruit, and Pliny the Elder even goes as far as admiring how well nature has hidden this fruit of apparently so little value.<ref name=":0" /> In the beginning of the Christian era, people probably started to realise the value and versatility of sweet chestnut wood, leading to a slow spread of the cultivation of ''C. sativa'' trees, a theory that is supported by pollen data and literary sources, as well as the increased use of sweet chestnut wood as poles and in supporting structures, wood works and pier building between A.D. 100 and 600.<ref name=":0"/>

Increasing sweet chestnut pollen appearances in Switzerland, France, Germany and the Iberian peninsula in the first century A.D. suggests the spreading of cultivated sweet chestnut trees by the Romans.<ref>{{Cite book |last=van Mourik |first=J. M. |title=Pollen profiles of slope deposits in the Galician area (N.W. Spain) |year=1986 |isbn=978-90-6809-018-5 |location=Amsterdam, Netherlands}}</ref><ref>{{Cite journal |last=Santos |first=Luisa |date=September 2000 |title=History of vegetation during the Holocene in the Courel and Queixa Sierras, Galicia, northwest Iberian Peninsula |journal=Journal of Quaternary Science |volume=15 |issue=6 |pages=621–632 |bibcode=2000JQS....15..621S |doi=10.1002/1099-1417(200009)15:6<621::AID-JQS524>3.0.CO;2-L}}</ref> Contrary to that notion, other scientists found no indication of the Romans spreading ''C. sativa'' before the fifth century.<ref>{{Cite journal |last=Di Pasquale |first=Gaetano |date=December 2010 |title=Reworking the idea of chestnut (''Castanea sativa'' Mill.) cultivation in Roman times: New data from ancient Campania |url=https://www.researchgate.net/publication/233903777 |journal=Plant Biosystems |volume=144 |issue=4 |pages=865–873 |bibcode=2010PBios.144..865D |doi=10.1080/11263504.2010.491974 |s2cid=86527704 |via=ResearchGate}}</ref> While the husks of sweet chestnuts, dated to the third or early fourth century, have been identified from the bottom of a Roman well at Great Holts Farm, in Boreham in Essex, England; this deposit includes remains of other exotic food plants and provides no evidence that any of them originated locally. No other evidence of sweet chestnut in Roman Britain has been confirmed.<ref>{{cite journal |last1=Jarman |first1=R. |last2=Hazell |first2=Z. |last3=Campbell |first3=G. |last4=Webb |first4=J. |last5=Chambers |first5=F.M. |year=2019 |title=Sweet Chestnut (''Castanea sativa'' Mill.) in Britain: Re-assessment of its Status as a Roman Archaeophyte |url=http://eprints.glos.ac.uk/6189/1/6189%20Chambers%20SWEET%20CHESTNUT%20%28Castanea%20sativa%20Mill.%29%20IN%20BRITAIN.pdf |journal=Britannia |volume=50 |pages=49–74 |doi=10.1017/S0068113X19000011 |s2cid=165935525}}</ref> Indeed, no centre of sweet chestnut cultivation outside the Italian peninsula in Roman times has been detected.<ref name=":0" /> Widespread use of chestnut in western Europe started in the early Middle Ages and flourished in the late Middle Ages.<ref name=":2">{{Cite journal |last=Livet |first=R. |date=1987 |title=J. R. Pitte – ''Terres de Castanide: hommes et paysages du châtaignier de l'Antiquité à nos jours'' [compte-rendu] |url=https://www.persee.fr/doc/medit_0025-8296_1987_num_60_1_2449 |journal=Méditerranée |volume=60 |page=52 |postscript=none}}, review of: {{cite book |last1=Pitte |first1=Jean-Robert |url=https://books.google.com/books?id=TH6azhG5yLcC |title=Terres de Castanide: Hommes et paysages du Châtaignier de l'Antiquité à nos jours |date=1986 |publisher=Fayard |isbn=978-2-213-01723-5}}</ref> In the mid-seventh-century Lombard laws, a composition of one solidi is set for felling a chestnut tree (or, also, hazel, pear or apple) belonging to another person (''Edictum Rothari'', No. 301, 643 AD). Since the beginning of the 20th century, due to depopulation of the countryside and the abandonment of the sweet chestnut as a staple food as well as the spread of chestnut blight and ink disease, ''C. sativa'' cultivation has dramatically decreased.<ref name=":2"/> Nowadays, sweet chestnut production is sometimes seen at a turning point again, because the development of high-value sweet chestnut products combined with changing needs of an urban society is leading to a revival in its cultivation.<ref name=":3"/>

=== Cultivation systems ===

Three different cultivation systems for the sweet chestnut can be distinguished:<ref name=":4">{{Cite journal |last=Lüdders |first=P. |date=February 2004 |title=Esskastanie |url=https://www.researchgate.net/publication/263692323 |journal=Erwerbs-Obstbau |volume=46}}</ref>

* ''Coppicing'': Mainly for wood extraction. Standard conditions yield 15 m3 wood per ha per year. * ''Selve'': Fruit production from grafted trees. The trees have a short trunk and a large crown. The trees are planted at a high density, and the ground between the trees is often used as pasture. * ''High forest:'' Wood and fruit production. This cultivation form is less intensive with a yield of 4–12 dt/ha and replacement of trees every 50–80 years. The trees grow from seeds and build a dense canopy.

The field management is dependent on the cultivation system. While cleaning the soil from the leaves and pruning is the norm, the use of fertiliser, irrigation and pesticides is less common and reserved for more intensive cultivation.<ref>{{Cite conference |last=Mariotti |first=Barbara |date=16–19 October 2008|title=Tradizione, innovazione e sostenibilità: una selvicoltura per il castagno da frutto |url=https://www.researchgate.net/publication/260001514|conference=III Congresso Nazionale Selvicoltura |pages=851–857 |doi=10.4129/CNS2008.113 |doi-broken-date=23 October 2025 |isbn=978-88-87553-16-1 }}</ref>

<gallery class=center mode=nolines widths=160 heights=160 caption="Cultivation systems"> Coppiced sweet chestnut woodland.jpg|Coppice Castanea sativa orchard in Andalusia, Spain 01.jpg|Orchard Steni forest-Δάσος Στενής.jpg|Chestnut-oak-pine forest </gallery>

=== Requirements ===

The sweet chestnut tree grows well on limestone-free, deeply weathered soil.<ref name=":5">{{Cite web |last=Koch |first=Henrike |date=31 March 2012 |title=Projektstudie: Die Edelkastanie auf Obstwiesen – Eine Alternative zum Kirschanbau? |trans-title=Project study: The sweet chestnut in orchards – an alternative to cherry cultivation? |url=http://www.wald-rlp.de/fileadmin/website/sativa/downloads/Projektstudie_Edelkastanie.pdf |archive-url=https://web.archive.org/web/20190227120829/http://www.wald-rlp.de/fileadmin/website/sativa/downloads/Projektstudie_Edelkastanie.pdf |archive-date=27 February 2019 |website=State forests of Rhineland-Palatinate |language=de}}</ref> The optimal pH value of the soil is between 4.5 and 6, and the tree cannot tolerate soil compaction.<ref name=":4" /> The tolerance to wet ground and to clay-rich soils is very low.<ref name=":63">{{Cite book |last=Conedera |first=Marco |title=European Atlas of Forest Tree Species – Chapter: ''Castanea sativa'' in Europe: distribution, habitat, usage and threats |publisher=Publication Office of the European Union |year=2016 |isbn=978-92-79-36740-3}}</ref> It is a heat-loving tree which needs a long vegetation period. The optimal average temperature is between {{cvt|8 and 15|°C}}<ref name=":4" /> and in January the temperature should preferably not be below {{cvt|-1|°C}}<ref name=":5" /> but it may tolerate temperatures as low as {{cvt|-15|°C}}.<ref name=":4" /> Low temperature in autumn can damage the fruit.<ref name=":5" /> The maximal altitude is strongly dependent on the climate. In general, the climate should be similar to viticulture.<ref name=":4" /> Optimal precipitation is between {{Convert|400 and 1600|mm}}.<ref name=":63" /> Before planting, seeds must be stratified at {{cvt|2-3|°C}} so germination can start 30–40 days later. After a year, the young trees are transplanted.<ref name=":4" />

=== Harvest ===

[[File:Romagne 86 Châtaignes 2008.jpg|thumb|Harvested chestnuts (''Castanea sativa'') in Romagne, Vienne, France]]

A tree grown from seed may take 20 years or more before it bears fruit, but a grafted cultivar such as 'Marron de Lyon' or 'Paragon' may start production within five years of being planted. Both cultivars bear fruit with a single large nut, rather than the usual two to four smaller nuts.<ref name="PFAF" />

The fruit yield per tree is usually between {{convert|30–100|kg|abbr=off}}, but can get as high as {{convert|300|kg|abbr=on}}.<ref name=":4" /> Harvest time is between middle of September and middle of November. There are three harvesting techniques:

* By hand: The sweet chestnuts are harvested by rake or broom, with a harvest speed of {{convert|5 to 30|kg|abbr=on}} every hour depending on the soil relief. Also, the capsule makes the harvest more complicated and even painful for the worker.<ref name=":63" /> * By hand with nets: This technique is less time-consuming and protects the nuts from damage. However, setting up the nets is labour intensive. * Mechanical: The fruit are collected with a machine that works like a vacuum cleaner.

=== Post-harvest treatment ===

The most widespread treatment before storage is water curing, a process in which the sweet chestnuts are immersed in water for nine days.<ref name=":7">{{Cite journal |last=Botondi |date=2009 |title=Technological Parameters of Water Curing Affect Postharvest Physiology and Storage of Marrons (''Castanea sativa'' Mill., Marrone Fiorentino) |url=https://www.academia.edu/5513085 |journal=Postharvest Biology and Technology |volume=51 |pages=97–103 |doi=10.1016/j.postharvbio.2008.06.010}}</ref> This is to limit the main storage problems threatening the sweet chestnut, fungi development and the presence of insect larvae.<ref name=":7" /> As an alternative to water curing, hot water treatment is also commercially used.{{citation needed|date=August 2024}}

After water treatment, the chestnuts are stored in a controlled environment with high carbon dioxide concentrations. In contrast to a cold storage system, where the nuts are stored at low temperatures in untreated air, the controlled environment method avoids flesh hardening which negatively impacts the processability of the product.<ref name=":7"/>

=== Cultivars ===

The ornamental cultivar ''Castanea sativa'' 'Albomarginata'<ref>{{cite web |title=RHS Plant Selector – ''Castanea sativa'' 'Albomarginata' |url=https://www.rhs.org.uk/Plants/93770/Castanea-sativa-Albomarginata-(v)/Details |access-date=2020-04-17}}</ref> has gained the Royal Horticultural Society's Award of Garden Merit. Cultivars of French origin include Bouche de Betizac, Maraval, Marigoule, Marsol, and Precoce Migoule. Cultivars of American origin include Colossal and Labor Day.{{cn|date=March 2026}}

== Uses ==

The species is widely cultivated for its edible seeds (also called chestnuts), and for its wood.

=== Nutrition ===

{{nutritionalvalue | name = Sweet chestnut (''Castanea sativa''), raw, unpeeled | water = 48.65 g | kJ = 891 | protein = 2.42 g | fat = 2.26 g | satfat = 0.425 g | monofat = 0.780 g | polyfat = 0.894 g | carbs = 45.54 g | fibre = 8.1 g | calcium_mg = 27 | copper_mg = 0.447 | iron_mg = 1.01 | magnesium_mg = 32 | phosphorus_mg = 93 | potassium_mg = 518 | sodium_mg = 3 | manganese_mg = 0.952 | zinc_mg = 0.52 | vitC_mg = 43.0 | thiamin_mg = 0.238 | riboflavin_mg = 0.168 | niacin_mg = 1.179 | pantothenic_mg = 0.509 | vitB6_mg = 0.376 | folate_ug = 62 | vitB12_ug = 0.00 | vitA_ug = 1  | tryptophan = 0.027 g | threonine = 0.086 g | isoleucine = 0.095 g | leucine = 0.143 g | lysine = 0.143 g | methionine = 0.057 g | cystine = 0.077 g | phenylalanine = 0.102 g | tyrosine = 0.067 g | valine = 0.135 g | arginine = 0.173 g | histidine = 0.067 g | alanine = 0.161 g | aspartic acid = 0.417 g | glutamic acid = 0.312 g | glycine = 0.124 g | proline = 0.127 g | serine = 0.121 g | source_usda = 1 | note = [https://fdc.nal.usda.gov/food-details/170574/nutrients Link to USDA Database entry] }}

The fat content is low and dominated by unsaturated fatty acids.<ref name=":9">{{Cite journal |last1=Borges |first1=Olga |last2=Gonçalves |first2=Berta |last3=de Carvalho |first3=José L. Soeiro |last4=Correia |first4=Paula |last5=Silva |first5=Ana Paula |date=February 2008 |title=Nutritional quality of chestnut (''Castanea sativa'' Mill.) cultivars from Portugal |journal=Food Chemistry |volume=106 |issue=3 |pages=976–984 |doi=10.1016/j.foodchem.2007.07.011 |issn=0308-8146 |hdl=10348/6419 |hdl-access=free}}</ref><ref>{{Cite journal |last1=De Vasconcelos |first1=Maria Do Carmo Barbosa Mendes |last2=Bennett |first2=Richard N. |last3=Rosa |first3=Eduardo A. S. |last4=Cardoso |first4=Jorge Ventura Ferreira |date=May 2007 |title=Primary and Secondary Metabolite Composition of Kernels from Three Cultivars of Portuguese Chestnut (''Castanea sativa'' Mill.) at Different Stages of Industrial Transformation |journal=Journal of Agricultural and Food Chemistry |volume=55 |issue=9 |pages=3508–3516 |doi=10.1021/jf0629080 |pmid=17407304 |bibcode=2007JAFC...55.3508D |issn=0021-8561}}</ref> Sweet chestnut is a good source of starch.<ref name=":10">{{Cite book |last=Griffith |first=Vaughan, J. G. (John |title=The new Oxford book of food plants |date=2009 |publisher=Oxford University Press |others=Geissler, Catherine; Nicholson, Barbara; Dowle, Elisabeth; Rice, Elizabeth |isbn=978-0-19-156774-2 |location=Oxford, England |oclc=500808884}}</ref><ref>{{Cite journal |last1=Künsch |first1=U. |last2=Schärer |first2=H. |last3=Patrian |first3=B. |last4=Hurter |first4=J. |last5=Conedera |first5=M. |last6=Sassella |first6=A. |last7=Jermini |first7=M. |last8=Jelmini |first8=G. |date=July 1999 |url=https://www.actahort.org/books/494/494_17.htm |journal=Acta Horticulturae |issue=494 |pages=119–128 |doi=10.17660/actahortic.1999.494.17 |issn=0567-7572 |title=Quality Assessment of Chestnut Fruits |access-date=2018-12-02 |archive-date=2022-03-03 |archive-url=https://web.archive.org/web/20220303200541/https://www.actahort.org/books/494/494_17.htm |url-access=subscription}}</ref> The energy value per 100 g (3.5 oz) of ''C. sativa'' amounts to 891 kJ (213 kcal) (table).<ref>{{Cite journal |last1=Fernandes |first1=Ângela |last2=Barreira |first2=João C.M. |last3=Antonio |first3=Amilcar L. |last4=Bento |first4=Albino |last5=Luisa Botelho |first5=M. |last6=Ferreira |first6=Isabel C.F.R. |date=September 2011 |title=Assessing the effects of gamma irradiation and storage time in energetic value and in major individual nutrients of chestnuts |journal=Food and Chemical Toxicology |volume=49 |issue=9 |pages=2429–2432 |doi=10.1016/j.fct.2011.06.062 |pmid=21740949 |issn=0278-6915}}</ref> ''C. sativa'' nuts are characterised by high moisture content, which ranges from 41% to 59%.<ref>{{Cite journal |last1=De La Montaña Mı́guelez |first1=J. |last2=Mı́guez Bernárdez |first2=M. |last3=Garcı́a Queijeiro |first3=J. M. |date=February 2004 |title=Composition of varieties of chestnuts from Galicia (Spain) |journal=Food Chemistry |volume=84 |issue=3 |pages=401–404 |doi=10.1016/s0308-8146(03)00249-8 |issn=0308-8146}}</ref> The chestnut provides a good source of copper, phosphorus, manganese and potassium (table).<ref name=":9" /> Its sugar content ranges from 14% to 20% dry weight, depending on the cultivar.<ref name=":11">{{Cite journal |last1=Neri |first1=L. |last2=Dimitri |first2=G. |last3=Sacchetti |first3=G. |date=February 2010 |title=Chemical composition and antioxidant activity of cured chestnuts from three sweet chestnut (''Castanea sativa'' Mill.) ecotypes from Italy |journal=Journal of Food Composition and Analysis |volume=23 |issue=1 |pages=23–29 |doi=10.1016/j.jfca.2009.03.002 |issn=0889-1575}}</ref> Fructose is mostly responsible for the sweet taste.<ref name=":11" />

=== Food ===

==== Culinary uses ====

The species' large genetic diversity and different cultivars are exploited for uses such as flour, boiling, roasting, drying, and sweets.<ref name=":16"/> The skin of raw peeled chestnuts can be removed by quickly blanching the nuts after scoring them by a cross slit at the tufted end. Once cooked, chestnuts acquire a sweet flavor and a floury texture similar to the sweet potato. The cooked nuts can be used for stuffing poultry, as a vegetable or in nut roasts. They can also be used in confections, puddings, desserts and cakes. They are used for flour, bread making, a cereal substitute, coffee substitute, a thickener in soups and other cookery uses, as well as for fattening stock. A sugar can be extracted from them.<ref name="PFAF"/> The Corsican variety of polenta (called ''pulenta'') is made with sweet chestnut flour. A local variety of Corsican beer also uses chestnuts. The product is sold as a sweetened paste mixed with vanilla, {{interlanguage link |crème de marrons |fr}}, sweetened or unsweetened as chestnut purée or ''purée de marron'', and candied chestnuts as ''marrons glacés''.<ref>Lori Alden. 2006. The Cook's Thesaurus. [http://www.foodsubs.com/Nutseed.html nut pastes].</ref> Roman soldiers were given chestnut porridge before going into battle.<ref name="Kew"/>

<gallery class=center mode=nolines widths=160 heights=160> Caldarroste, geröstete Kastanien, roasted Chestnuts.jpg |Roasted chestnuts Kestaneci chestnut vendor.jpg |Street vendors in Istanbul Marrons glacés.jpg |Marrons glacés Crema di castagne o confettura di marroni.jpg |{{interlanguage link |Crème de marrons |fr}} </gallery>

==== Effect of processing ====

Most sweet chestnut nuts are consumed in processed forms, which has an impact on the nutrient composition. Its naturally high concentration of organic acids is a key factor influencing the organoleptic characteristics of fruit and vegetables, namely flavour.<ref name=":10" /> Organic acids are thought to play an important role against diseases as an antioxidant.<ref name=":12">{{Cite journal |last1=Silva |first1=Branca M. |last2=Andrade |first2=Paula B. |last3=Valentão |first3=Patrícia |last4=Ferreres |first4=Federico |last5=Seabra |first5=Rosa M. |last6=Ferreira |first6=Margarida A. |date=July 2004 |title=Quince (''Cydonia oblonga'' Miller) Fruit (Pulp, Peel, and Seed) and Jam: Antioxidant Activity |journal=Journal of Agricultural and Food Chemistry |volume=52 |issue=15 |pages=4705–4712 |doi=10.1021/jf040057v |pmid=15264903 |bibcode=2004JAFC...52.4705S |url=https://www.academia.edu/4147773 |via=Academia.edu}}</ref><ref>{{Cite journal |last1=Blomhoff |first1=Rune |last2=Carlsen |first2=Monica H. |last3=Andersen |first3=Lene Frost |last4=Jacobs |first4=David R. |date=September 2006 |title=Health benefits of nuts: potential role of antioxidants |journal=British Journal of Nutrition |volume=96 |issue=S2 |pages=S52–S60 |doi=10.1017/BJN20061864 |pmid=17125534 |issn=1475-2662 |doi-access=free}}</ref> Heat appears to be the most influencing factor when it comes to decreasing the organic acid content. However, even after heating sweet chestnuts, antioxidant activity remains relatively high.<ref name=":13">{{Cite journal |last1=Barros |first1=Ana I.R.N.A. |last2=Nunes |first2=Fernando M. |last3=Gonçalves |first3=Berta |last4=Bennett |first4=Richard N. |last5=Silva |first5=Ana Paula |date=September 2011 |title=Effect of cooking on total vitamin C contents and antioxidant activity of sweet chestnuts (''Castanea sativa'' Mill.) |journal=Food Chemistry |volume=128 |issue=1 |pages=165–172 |doi=10.1016/j.foodchem.2011.03.013 |pmid=25214344 |hdl=10348/6571 |hdl-access=free}}</ref> On the other hand, the consumer must consider that roasting, boiling or frying has a big impact on the nutritional profile of chestnut.<ref name=":12" /><ref>{{Cite journal |last1=Ribeiro |first1=Bárbara |last2=Rangel |first2=Joana |last3=Valentão |first3=Patrı́cia |last4=Andrade |first4=Paula B. |last5=Pereira |first5=José Alberto |last6=Bölke |first6=Hanna |last7=Seabra |first7=Rosa M. |date=January 2007 |title=Organic acids in two Portuguese chestnut (''Castanea sativa'' Miller) varieties |journal=Food Chemistry |volume=100 |issue=2 |pages=504–508 |doi=10.1016/j.foodchem.2005.09.073 |hdl=10198/735 |hdl-access=free}}</ref> Vitamin C content falls by as much as 54% when boiled and by as much as 77% when roasted. Nevertheless, roasted or boiled chestnuts may still be a solid vitamin C source, since 100 grams still represents about 20% of the recommended daily dietary intake.<ref>{{cite journal |last1=Barros |first1=Ana I.R.N.A. |last2=Nunes |first2=Fernando M. |last3=Gonçalves |first3=Berta |last4=Bennett |first4=Richard N. |last5=Silva |first5=Ana Paula |title=Effect of cooking on total vitamin C contents and antioxidant activity of sweet chestnuts (''Castanea sativa'' Mill.) |journal=Food Chemistry |volume=128 |issue=1 |date=2011 |doi=10.1016/j.foodchem.2011.03.013 |pages=165–172|hdl=10348/6571 |hdl-access=free }}</ref>

The sugar content is also affected by the high temperatures. Four processes are decisive for the degrading process of sugar while cooking; hydrolysis of starch to oligosaccharide and monosaccharide, decomposition of sucrose to glucose and fructose, caramelisation of sugars and degradation of sugars.<ref>{{Cite journal |last1=Attanasio |first1=Gerardina |last2=Cinquanta |first2=Luciano |last3=Albanese |first3=Donatella |last4=Matteo |first4=Marisa Di |date=December 2004 |title=Effects of drying temperatures on physico-chemical properties of dried and rehydrated chestnuts (''Castanea sativa'') |journal=Food Chemistry |volume=88 |issue=4 |pages=583–590 |doi=10.1016/j.foodchem.2004.01.071}}</ref> Organic acids are also affected by high temperatures; their content decreases about 50% after frying, and 15% after boiling.<ref name=":13" /> Responsible for the aromatic characteristics of cooked chestnuts is the effect of degradation of saccharides, proteins and lipids, the caramelisation of saccharides and the maillard reaction that is reducing sugar and amino acids.<ref>{{Cite journal |last1=Morini |first1=G. |last2=Maga |first2=J. A. |date=May 1995 |title=Volatile compounds in roasted and boiled Chinese chestnuts (''Castanea molissima'') |journal=LWT – Food Science and Technology |volume=28 |issue=6 |pages=638–640 |doi=10.1016/0023-6438(95)90014-4 |doi-access=free}}</ref><ref>{{Cite journal |last1=Li |first1=Qian |last2=Shi |first2=Xianhe |last3=Zhao |first3=Qiaojiao |last4=Cui |first4=Yahui |last5=Ouyang |first5=Jie |last6=Xu |first6=Fang |date=June 2016 |title=Effect of cooking methods on nutritional quality and volatile compounds of Chinese chestnut (''Castanea mollissima'' Blume) |journal=Food Chemistry |volume=201 |pages=80–86 |doi=10.1016/j.foodchem.2016.01.068 |pmid=26868551}}</ref>

=== Wood ===

[[File:Penshurst Place, Baron's Hall, The magnificent chestnut roof 1 - geograph.org.uk - 5767117.jpg|thumb|Medieval chestnut roof of Penshurst Place, Kent, England]]

This tree responds very well to coppicing, which is still practised in Britain, and produces a good crop of tannin-rich wood every 12 to 30 years, depending on intended use and local growth rate. The tannin renders the young growing wood durable and weather resistant for outdoor use, thus suitable for posts, fencing or stakes.<ref name="oleg">{{cite book |last=Polunin |first=Oleg |author-link=Oleg Polunin |title=Trees and Bushes of Britain and Europe |publisher=Paladin |year=1973 |pages=51, 188 and 195}}</ref> The wood is of light colour, hard and strong. It is used to make furniture, barrels (sometimes used to age balsamic vinegar), and roof beams notably in southern Europe (for example in houses of the Alpujarra, Spain, in southern France and elsewhere). The timber has a density of 560 kg per cubic metre,<ref name="niche">[http://www.nichetimbers.co.uk/native-hardwood/chestnut/ Chestnut] {{Webarchive|url=https://web.archive.org/web/20100205113555/http://www.nichetimbers.co.uk/native-hardwood/chestnut/ |date=2010-02-05 }}. Niche Timbers. Accessed 19-08-2009.</ref> and due to its durability in ground contact is often used for external purposes such as fencing.<ref name="niche" /> It is a good fuel, though not favoured for open fires as it tends to spit.<ref name="PFAF" />

Tannin is found in the following proportions on a 10% moisture basis: bark (6.8%), wood (13.4%), seed husks (10–13%). The leaves too contain tannin.<ref name="PFAF"/>

=== Herbalism ===

Sweet chestnut is one of the 38 substances used to prepare Bach flower remedies,<ref name="Vohra2004">{{cite book |author=D. S. Vohra |url=https://books.google.com/books?id=icG8onA0ys8C&pg=PR3 |title=Bach Flower Remedies: A Comprehensive Study |date=1 June 2004 |publisher=B. Jain Publishers |isbn=978-81-7021-271-3 |page=3 |access-date=2 September 2013}}</ref> a kind of alternative medicine promoted for its supposed effect on health. However, according to Cancer Research UK, "there is no scientific evidence to prove that flower remedies can control, cure or prevent any type of disease, including cancer".<ref>{{cite web |date=2017-08-30 |title=Flower remedies |archive-url=https://web.archive.org/web/20130810115036/http://www.cancerresearchuk.org/cancer-help/about-cancer/treatment/complementary-alternative/therapies/flower-remedies |access-date=2 September 2013 |publisher=Cancer Research UK|url=http://www.cancerresearchuk.org/cancer-help/about-cancer/treatment/complementary-alternative/therapies/flower-remedies |archive-date=2013-08-10 }}</ref>

== References ==

== External links ==

* {{Wikispecies-inline}} * {{Commons category-inline|Castanea sativa}}

* [https://web.archive.org/web/20060903223150/http://cesonoma.ucdavis.edu/hortic/pdf/chestnut_99.pdf U.C. Davis, California: ''Castanea sativa'' in horticulture] * [http://www.pfaf.org/user/Plant.aspx?LatinName=Castanea+sativa Plants for a Future database: ''Castanea sativa''] * [http://www.euforgen.org/species/castanea-sativa/ ''Castanea sativa''] – distribution map, genetic conservation units and related resources. European Forest Genetic Resources Programme (EUFORGEN)

sativa Category:Edible nuts and seeds Category:Flora of Western Asia Category:Flora of Europe Category:Flora of Greece Category:Flora of Italy Category:Flora of Montenegro Category:Trees of Europe Category:Medicinal plants of Asia Category:Medicinal plants of Europe Category:Trees of Mediterranean climate Category:Garden plants of Asia Category:Garden plants of Europe Category:Ornamental trees Category:Fruit trees Category:Taxa named by Philip Miller