View source for Instant coffee

{{Short description|Drink made by rehydrating powdered coffee}}
{{use dmy dates |date=August 2021}}
{{Redir|Coffee powder|finely ground coffee|Coffee ground}}
{{For|the Canadian artist collective|Instant Coffee (artist collective)}}
{{Infobox food
| name            = Instant coffee
| image           = Instant coffee.jpg
| alt             = Instant coffee granules
| caption         = Instant coffee granules
| type            = Coffee
| place_of_origin = [[New Zealand]]
| main_ingredient = [[freeze-dried]] coffee
| variations      =
| creator         = David Strang
| region          = [[Invercargill]], [[Southland, New Zealand|Southland]]
}}
'''Instant coffee''' is a beverage derived from brewed [[coffee bean]]s that enables consumers to quickly prepare hot coffee by adding hot water or milk to ''coffee solids'' and then stirring. {{anchor|Coffee powder}}'''Instant coffee solids''' in powdered or crystallized form (also called '''soluble coffee''', '''coffee crystals''', '''coffee powder''', or '''powdered coffee''') refers to  [[dehydration|dehydrated]] and packaged solids sold at retail and used to make instant coffee. The product was invented in 1890 in [[Invercargill]], the largest city in [[Southland Region|Southland]], New Zealand. Instant coffee solids are commercially prepared by either [[freeze-drying]] or [[spray drying]], after which it can be rehydrated. Instant coffee is also manufactured in a concentrated liquid form as a beverage.

Advantages of instant coffee include speed of preparation (instant coffee dissolves quickly in hot water), lower shipping weight and volume than beans or ground coffee (to prepare the same amount of beverage), and long [[shelf life]]—though instant coffee can spoil if not kept dry.  Instant coffee also reduces cleanup since there are no coffee grounds, and at least one study has found that it has a lower environmental footprint{{how much|date=July 2022}} than drip filter coffee and capsule espresso coffee, on a prepared beverage basis, disregarding quality and appeal of the beverage produced.<ref>{{Cite journal| doi = 10.1016/j.jclepro.2009.04.011| issn = 0959-6526| volume = 17| issue = 15| pages = 1351–1358| last1 = Humbert| first1 = Sebastien| last2 = Loerincik| first2 = Yves| last3 = Rossi| first3 = Vincent| last4 = Margni| first4 = Manuele| last5 = Jolliet| first5 = Olivier| title = Life cycle assessment of spray dried soluble coffee and comparison with alternatives (drip filter and capsule espresso)| journal = Journal of Cleaner Production| date =2009}}</ref>

==History==
[[File:David Strang Coffee Mills.JPG|thumb|David Strang Coffee Mills]]
A concentrated coffee/milk/sugar mixture was produced for the Union army during the [[American Civil War]] under the name ''Essence of Coffee'', a teaspoonful of which was mixed with a cup of hot water. It had the consistency of [[axle grease]], and proved so unpopular with the troops that it was soon discontinued.<ref>Wiley, Bell Irvin. ''The Life of Billy Yank.'' Doubleday, New York 1971. p. 241</ref> The brand [[Camp Coffee]], a coffee and [[chicory]] essence, was first produced in 1876 by Paterson & Sons Ltd in Scotland.

The invention for instant or soluble coffee was filed 28 January 1889 and patented in 1890, by David Strang of [[Invercargill]], New Zealand, under patent number 3518.<ref>{{cite web |url=http://atojs.natlib.govt.nz/cgi-bin/atojs?a=d&d=AJHR1890-I.2.3.2.1&e=-------10--1------0-- |year=1890 |title=First Annual Report |location=New Zealand |work=Patents, Designs and Trade-marks|page=9 }}</ref> It was sold under the trading name Strang's Coffee<ref>[http://paperspast.natlib.govt.nz/cgi-bin/paperspast?a=d&d=CHP18930907.2.32.2 Papers Past — Press — 7 September 1893 — Page 3 Advertisements Column 2<!-- Bot generated title -->]</ref> citing the patented "Dry Hot-Air" process. Some modern sources have credited French humorist and writer [[Alphonse Allais]] with the invention.<ref>{{Cite web|last=Tim|date=2019-07-01|title=The Invention of Instant Coffee – Who, What, Where, and How?|url=https://procaffeination.com/the-invention-of-instant-coffee-who-what-where-and-how/|access-date=2021-08-07|website=Procaffeination|language=en-US}}</ref><ref>{{Cite web|date=2021-05-24|title=When Was Instant Coffee Invented?|url=https://coffeeaffection.com/when-was-instant-coffee-invented/|access-date=2021-08-07|website=Coffee Affection|language=en-US}}</ref>

The invention was previously attributed to [[Satori Kato]], a Japanese scientist working in Chicago in 1901. Kato introduced the powdered substance in [[Buffalo, New York]], at the [[Pan-American Exposition]].<ref>Carlisle, Rodney (2004). ''Scientific American Inventions and Discoveries'', p.355. John Wiley & Songs, Inc., New Jersey. {{ISBN|0-471-24410-4}}.</ref> [[George Constant Louis Washington]] developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The [[Nescafé]] brand, which introduced a more advanced coffee refining process, was launched in 1938.{{cn|date=October 2024}}

High-vacuum freeze-dried coffee was developed shortly after [[World War II]], as an indirect result of wartime research into other areas.{{cn|date=October 2024}} The [[William Appleton Coolidge|National Research Corporation]] (NRC) was formed in [[Massachusetts]] as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce [[penicillin]], [[blood plasma]], and [[streptomycin]] for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corporation to produce concentrated [[orange juice]] powder and originally sold its product to the [[United States Army]]. That company later changed its name to [[Minute Maid]].
<!-- "Satori Kato" links here -->

==Use==
[[File:Una tazza di caffè solubile 8.jpg|thumb|upright|A cup of instant coffee from Italy]]
Close to 50% of the world's [[green coffee]] is used to produce instant coffee.<ref name="RamalakshmiRao2009">{{cite journal|last1=Ramalakshmi|first1=K.|last2=Rao|first2=L. Jagan Mohan|last3=Takano-Ishikawa|first3=Yuko|last4=Goto|first4=Masao|title=Bioactivities of low-grade green coffee and spent coffee in different in vitro model systems|journal=Food Chemistry|volume=115|issue=1|year=2009|pages=79–85|issn=0308-8146|doi=10.1016/j.foodchem.2008.11.063}}</ref>

===As food===
[[File:Instant Coffee In a Glass Jar.jpg|thumb|upright|Instant coffee in a glass jar]]
Instant coffee is available in powder or granulated form contained in glass and plastic jars, [[sachet]]s, or tins. The user controls the strength of the resulting product by adding less or more powder or granules to the water.

Instant coffee is also convenient for preparing iced coffee like the [[Greek frappé coffee|Greek frappé]].

In some countries, such as Portugal, Spain, and India, instant coffee is commonly mixed with hot milk instead of boiling water.<ref>{{Cite web|url=https://travelaway.me/the-curious-case-of-coffee-in-spain/|title=The Curious Case of Coffee in Spain|date=2012-04-18}}</ref> In other countries, such as South Korea, instant coffee commonly comes pre-mixed with [[non-dairy creamer]] and sugar and is called "coffee mix".<ref>{{cite web|url=https://www.koreatimes.co.kr/www/news/nation/2009/04/117_43613.html |title=Koreans Addicted to Instant Coffee |publisher=Koreatimes.co.kr |date=2009-04-22 |access-date=2013-11-17}}</ref> Said to have been popularised in the UK by [[G.I. (military)|GI]]s during [[World War II]], instant coffee still accounts for over 75 percent of coffee bought to drink in British homes, as opposed to well under 10 percent in the U.S. and France and one percent in Italy.<ref name="BBC News Magazine">{{cite news|last=Magazine Monitor|title=Why do Britons drink so much instant coffee?|url=https://www.bbc.co.uk/news/blogs-magazine-monitor-26869244|access-date=5 April 2014|newspaper=BBC News Magazine}}</ref>

In the United Kingdom, instant coffee granules are sometimes used to enhance the flavour of sauces used in preparing [[Bolognese_sauce#Spaghetti_bolognese|spaghetti Bolognese]].<ref>{{cite news|url=https://www.prima.co.uk/leisure/celebrity/a37267840/ruth-langsford-spaghetti-bolognese/|title=Ruth Langsford's secret spaghetti bolognese ingredient will divide fans|last=Quick|first=Lucy|date=10 August 2021|work=[[Prima (magazine)|Prima]]|accessdate=12 August 2021}}</ref><ref>{{cite news|url=https://www.businessinsider.com/sainsburys-suggests-adding-instant-coffee-to-spaghetti-2015-9?r=US&IR=T|title=This awkward spaghetti recipe is causing an online backlash against a British grocery store|last=Willet-Wei|first=Megan|date=8 September 2015|work=[[Business Insider]]|accessdate=12 August 2021}}</ref>

===Non-food uses===
Instant coffee is one of the ingredients in [[Caffenol]],<ref>{{cite web |url=https://caffenol.blogspot.com/2010/08/recipes.html |title=Comparison of different Caffenol formulas |website=caffenol.blogspot.com |date=August 17, 2010 }}</ref> a home-made, non-toxic [[black-and-white]] [[photographic developer]]. The other ingredients in the basic formula are [[ascorbic acid]] (vitamin C) and [[anhydrous]] [[sodium carbonate]]; some recipes also include [[potassium bromide]] as a fog-reducing agent. The active ingredient appears to be [[caffeic acid]]. Initial experiments on Caffenol were performed in 1995 at the [[Rochester Institute of Technology]];<ref>{{cite web |url=https://people.rit.edu/andpph/text-coffee.html |title=A Use for that Last Cup of Coffee: Film and Paper Development] Darkroom and Creative Camera Techniques |date=September 1995 |first=Scott |last=Williams }}</ref> addition of ascorbic acid began around 2000, yielding the improved Caffenol-C, which is less likely to stain negatives than the original formulation. Experiments have shown that cheaper, less desirable brands of coffee work better for this application than more expensive brands.<ref>{{cite web |url=https://caffenol.blogspot.com/2010/03/caffenol-c-m-recipe.html |title=Caffenol-C-M, recipe |date=March 2, 2010 }}</ref>

In crafts, Instant coffee can be used as a [[dye]] to stain paper and give the impression of it being aged.<ref>{{Cite web |date=2022-10-10 |title=How to stain paper with coffee {{!}} Bookbinding Workshop Singapore |url=https://www.bookbindingworkshopsg.com/how-to-stain-paper-with-coffee/ |access-date=2024-08-04 |language=en-US}}</ref>

==Production==
[[File:Close-up of a granule of Gold Blend instant coffee.jpg|thumb|Close-up view of a granule of [[Nescafé]] instant coffee]]
As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches {{convert|165|°C}} the roasting begins. It takes about 8–15 minutes to complete roasting. After cooling, the beans are then ground finely. Grinding reduces the beans to {{convert|0.5|to|1.1|mm|adj=on}} pieces. Until here, the process is in general the same as for other types of coffee.<ref name="MussattoMachado2011"/>

===Extraction===
To produce instant coffee, the soluble and volatile contents of the beans, which provide the coffee aroma and flavor, have to be extracted. This is done using water. Pressurized water heated to around {{convert|175|°C}} is used for this process. The coffee concentration in the liquid is then increased by either evaporation or by freeze concentration.<ref name="MussattoMachado2011">{{cite journal|last1=Mussatto|first1=Solange I.|last2=Machado|first2=Ercília M. S.|last3=Martins|first3=Silvia|last4=Teixeira|first4=José A.|title=Production, Composition, and Application of Coffee and Its Industrial Residues|journal=Food and Bioprocess Technology|volume=4|issue=5|year=2011|pages=661–672|issn=1935-5130|doi=10.1007/s11947-011-0565-z|hdl=1822/22361|s2cid=27800545|hdl-access=free}}</ref><ref>Archived at [https://ghostarchive.org/varchive/youtube/20211211/4G5LcVUcWAg Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20180311144244/https://www.youtube.com/watch?v=4G5LcVUcWAg Wayback Machine]{{cbignore}}: {{cite AV media |title=How It Works - Instant Coffee |medium=video |language=en |url=https://www.youtube.com/watch?v=4G5LcVUcWAg |access-date=4 March 2016 }}{{cbignore}}</ref>

===Freeze drying===
{{No footnotes|section|date=March 2016}}
[[Image:Production freeze dryer.JPG|thumb|right|A [[freeze drying|freeze dryer]]]]

The basic principle of [[freeze drying]] is the removal of water by [[sublimation (chemistry)|sublimation]].

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is more expensive, it generally results in a higher-quality product.

# The coffee extract is rapidly frozen and is broken into small granules. (Slower freezing would lead to larger ice crystals and a porous product; it can also affect the colour of the coffee granules).
# The granules are sifted and sorted on size.<ref name="MussattoMachado2011"/>
# Frozen coffee granules are placed in the drying chamber, often on metal trays.
# A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
# The drying chamber is warmed, most commonly by [[thermal radiation|radiation]], but [[heat conduction|conduction]] is used in some plants and [[convection]] has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
# Sublimation—the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
# The freeze-dried granules are removed from the chamber and packaged.

===Spray drying===
{{main|Spray drying}}
[[Image:Labspraydryer.svg|thumb|Laboratory-scale spray dryer.<br /> A=Solution or suspension to be dried in, B=Atomization gas in, 1= Drying gas in, 2=Heating of drying gas, 3=Spraying of solution or suspension, 4=Drying chamber, 5=Part between drying chamber and cyclone, 6=Cyclone, 7=Drying gas is taken away, 8=Collection vessel of product, arrows mean that this is co-current lab-spraydryer]]

Spray drying is preferred to freeze-drying in some cases because it allows larger scale economic production, shorter drying times, and because it produces fine rounded particles.

The process produces spherical particles about {{convert|300|μm}} in size with a density of 0.22&nbsp;g/cm<sup>3</sup>.<ref>{{cite book | title = Spray Drying Handbook | edition = 5th | first = K | last = Masters | year = 1991 | publisher = Longman Scientific & Technical | isbn = 978-0-582-06266-5 }}</ref> To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000&nbsp;rpm are able to process up to {{convert|6000|lb|kg}} of solution per hour.<ref>{{cite book | title = Encyclopedia of Chemical Processing and Design | editor = John J. McKetta | publisher = Marcel Dekker Inc | year = 1995 | isbn = 978-0-8247-2604-1 }}</ref> The use of [[spray wheel]]s requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.
* Completed in 5–30 seconds (dependent on factors such as heat, size of particle, and diameter of chamber).
* Moisture content change: IN = 75–85% OUT = 3–3.5%
* Air temperature: IN = {{convert|270|°C}} OUT = {{convert|110|°C}}

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

===Decaffeination===
{{See also|Decaffeination}}
In commercial processes, the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee's flavour and aroma processes.

===Byproducts===
The main byproduct of the instant coffee production process is spent coffee grounds. These grounds can be used as biomass, for example to produce heat used in the manufacturing process.<ref>{{cite web|url=http://www.madehow.com/Volume-3/Instant-Coffee.html|publisher=Madehow|title=Instant Coffee}}</ref> Roughly two times the mass in spent coffee grounds is generated for each quantity of soluble coffee.<ref>Pfluger, R. A. (1975). Soluble coffee processing. In C. L. Mantell
(Ed.), Solid wastes: origin, collection, processing, and disposal.
New York: Wiley.</ref>

==Composition==
The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66&nbsp;mg per cup (range 29–117&nbsp;mg per cup), with a median cup size of 225 ml (range 170–285 ml) and a caffeine concentration of 328&nbsp;μg/mL (range 102–559&nbsp;μg/mL).<ref name=gilbert1976>{{Cite journal
 | last1 = Gilbert | first1 = R.
 | last2 = Marshman | first2 = J.
 | last3 = Schwieder | first3 = M.
 | last4 = Berg | first4 = R.
 | title = Caffeine content of beverages as consumed
 | journal = Canadian Medical Association Journal
 | volume = 114
 | issue = 3
 | pages = 205–208
 | year = 1976
 | pmid = 1032351
 | pmc = 1956955
}}</ref> In comparison, drip or filter coffee was estimated to have a median caffeine content of 112&nbsp;mg, with a median concentration of 621&nbsp;μg/mL for the same cup size.<ref name=gilbert1976/>

Regarding antioxidants, the [[polyphenol]] content of a 180 ml cup of instant coffee has been estimated to be approximately 320&nbsp;mg, compared to approximately 400&nbsp;mg in a cup of brewed coffee of the same size.<ref>{{Cite journal | last1 = Bonita | first1 = J. | last2 = Mandarano | first2 = M. | last3 = Shuta | first3 = D. | last4 = Vinson | first4 = J. | title = Coffee and cardiovascular disease: In vitro, cellular, animal, and human studies | journal = Pharmacological Research | volume = 55 | issue = 3 | pages = 187–198 | year = 2007 | pmid = 17368041 | doi = 10.1016/j.phrs.2007.01.006}}</ref>

==Malabsorption==
Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee.<ref name=Morck1983>{{Cite journal
 | last1 = Morck | first1 = T.
 | last2 = Lynch | first2 = S.
 | last3 = Cook | first3 = J.
 | title = Inhibition of food iron absorption by coffee
 | journal = The American Journal of Clinical Nutrition
 | volume = 37
 | issue = 3
 | pages = 416–420
 | year = 1983
 | pmid = 6402915
| doi = 10.1093/ajcn/37.3.416
 }}</ref> It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.<ref name=Morck1983/> However, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.<ref name=Morck1983/>

==Regulation==
In the [[European Union]], regulations include the species of coffee bean, geographical origin, processing detail, year of crop, solvents used in decaffeination, and caffeine level.

Various institutions govern the coffee industry and help to achieve standardization and release information to the public, including the [[International Coffee Organization]] (London), Codex Alimentarius Commission of the UN (Rome), and [[National Coffee Association]] (New York).

==See also==
{{Portal|Coffee|Food}}
{{div col|colwidth=30em}}
* [[Dalgona coffee]]
* [[Instant breakfast]]
* [[Instant soup]]
* [[Instant tea]]
* [[List of instant foods]]
* [[List of dried foods]]
* [[Powdered milk]]
{{div col end}}

==References==
{{Reflist}}

==Bibliography==
* {{cite book | title = Encyclopedia of Chemical Technology, volume 6 | edition = 4th | editor = Romualdo Verzosa Jr.| publisher = John Wiley & Sons | year =  1993 | isbn = 978-0-471-52674-2 }}
* {{cite book | title = Spray Drying Handbook | edition = 5th | first = K | last = Masters | year = 1991 | publisher = Longman Scientific & Technical | isbn = 978-0-582-06266-5 }}
* {{cite book | title = Encyclopedia of Chemical Processing and Design | editor = John J. McKetta | publisher = Marcel Dekker Inc | year = 1995 | isbn = 978-0-8247-2604-1 }}

{{Commons category}}

{{coffee|nocat=1}}
{{Instant foods}}

{{Authority control}}

[[Category:New Zealand inventions]]
[[Category:Types of coffee]]
[[Category:Powdered drink mixes]]
[[Category:Products introduced in 1909]]