A typical dish of tomato ketchup
Place of originUnited Kingdom (mushroom variant), United States (tomato variant)
Main ingredientsTomatoes (or other main ingredients), sugar (or high fructose corn syrup), vinegar, salt, spices, and seasonings
Food energy
(per serving)
100 per serving (serving size 1 tbsp) kcal

Ketchup or catsup (/ˈkɛəp, ˈkætsup, ˈkɑːəp/) is a table condiment with a sweet and sour flavor. The unmodified term ("ketchup") now typically refers to tomato ketchup,[1] although early recipes for various different varieties of ketchup contained mushrooms, oysters, mussels, egg whites, grapes or walnuts, among other ingredients.[2][3]

Tomato ketchup is made from tomatoes, sugar, and vinegar, with seasonings and spices. The spices and flavors vary, but commonly include onions, allspice, coriander, cloves, cumin, garlic, and mustard, and sometimes include celery, cinnamon, or ginger.[citation needed] The market leader in the United States (60% market share) and the United Kingdom (82%) is Heinz Tomato Ketchup.[4][5] Tomato ketchup is often used as a condiment to dishes that are usually served hot and are fried or greasy: french fries and other potato dishes, hamburgers, hot dogs, chicken tenders, hot sandwiches, meat pies, cooked eggs, and grilled or fried meat. Ketchup is sometimes used as the basis for, or as one ingredient in, other sauces and dressings, and the flavor may be replicated as an additive flavoring for snacks, such as potato chips.[6]


Mushroom ketchup

Main article: Mushroom ketchup

Homemade mushroom ketchup in a plastic tub

In the United Kingdom, ketchup was historically prepared with mushrooms as a primary ingredient, rather than tomatoes.[7][8][9] In the United States, mushroom ketchup dates back to at least 1770, and was prepared by British colonists in the Thirteen Colonies.[10]

Tomato ketchup

Tomato ketchup and other condiments
Tomato ketchup next to raw tomatoes

Many variations of ketchup were created, but the tomato-based version did not appear until around a century after other types. An early recipe for "Tomato Catsup" from 1817 includes anchovies:[11]

  1. Gather a gallon of fine, red, and full ripe tomatas; mash them with one pound of salt.
  2. Let them rest for three days, press off the juice, and to each quart add a quarter of a pound of anchovies, two ounces of shallots, and an ounce of ground black pepper.
  3. Boil up together for half an hour, strain through a sieve, and put to it the following spices; a quarter of an ounce of mace, the same of allspice and ginger, half an ounce of nutmeg, a drachm of coriander seed, and half a drachm of cochineal.
  4. Pound all together; let them simmer gently for twenty minutes, and strain through a bag: when cold, bottle it, adding to each bottle a wineglass of brandy. It will keep for seven years.

By the mid-1850s, the anchovies had been dropped.[11]

The term ketchup first appeared in 1682.[12] Ketchup recipes began to appear in British and then American cookbooks in the 18th century. James Mease published the first known tomato ketchup recipe in 1812. In 1824, a ketchup recipe using tomatoes appeared in The Virginia Housewife (an influential 19th-century cookbook written by Mary Randolph, Thomas Jefferson's cousin). Tomato ketchup was sold locally by farmers. Jonas Yerkes is credited as the first American to sell it in a bottle.[13] By 1837, he had produced and distributed the condiment nationally.[14] Shortly thereafter, other companies followed suit. F. & J. Heinz launched their tomato ketchup in 1876.[15] American cooks also began to sweeten ketchup in the 19th century.[16] The Webster's Dictionary of 1913 defined "catsup" as: "table sauce made from mushrooms, tomatoes, walnuts, etc. [Also written as ketchup]." As the century progressed, tomato ketchup began its ascent in popularity in the United States. Tomato ketchup was popular long before fresh tomatoes were. People were less hesitant to eat tomatoes as part of a highly processed product that had been cooked and infused with vinegar and spices.[17]

Heinz Tomato Ketchup was advertised: "Blessed relief for Mother and the other women in the household!", a slogan which alluded to the lengthy process required to produce tomato ketchup in the home.[18] With industrial ketchup production and a need for better preservation there was a great increase of sugar in ketchup, leading to the typically sweet and sour formula of today.[11] In Australia, it was not until the late 19th century that sugar was added to tomato sauce, initially in small quantities, but today it contains just as much as American ketchup and only differed in the proportions of tomatoes, salt and vinegar in early recipes.[19]

Modern ketchup emerged in the early years of the 20th century, out of a debate over the use of sodium benzoate as a preservative in condiments. Harvey W. Wiley, the "father" of the US Food and Drug Administration, challenged the safety of benzoate which was banned in the 1906 Pure Food and Drug Act. In response, entrepreneurs including Henry J. Heinz, pursued an alternative recipe that eliminated the need for that preservative.[citation needed] Katherine Bitting, a bacteriologist working for the U.S. Department of Agriculture, carried out research in 1909 that proved increasing the sugar and vinegar content of the product would prevent spoilage without use of artificial preservatives. She was assisted by her husband, Arvil Bitting, an official at that agency.[20]

Prior to Heinz (and his fellow innovators), commercial tomato ketchups of that time were watery and thin, in part because they used unripe tomatoes, which were low in pectin.[21] They had less vinegar than modern ketchups; by pickling ripe tomatoes, the need for benzoate was eliminated without spoilage or degradation in flavor. But the changes driven by the desire to eliminate benzoate also produced changes[clarification needed] that some experts (such as Andrew F. Smith[22]) believe were key to the establishment of tomato ketchup as the dominant American condiment.

Later innovations

In fast-food outlets, ketchup is often dispensed in small sachets or tubs. Diners tear the side or top and squeeze the ketchup out of the ketchup packets, or peel the foil lid off the tub for dipping. In 2011, Heinz began offering a new measured-portion package, called the "Dip and Squeeze" packet, which can be opened in either way, giving both options.[23]

Some fast food outlets previously dispensed ketchup from hand-operated pumps into paper cups. This method has made a comeback in the first decades of the 21st century, as cost and environmental concerns over the increasing use of individual plastic ketchup tubs were taken into account.

In October 2000, Heinz introduced colored ketchup products called EZ Squirt, which eventually included green (2000), purple (2001), mystery (pink, orange, or teal, 2002), and blue (2003).[24] These products were made by adding food coloring to the traditional ketchup. By January 2006, these products were discontinued.[25]


The term used for the sauce varies. Ketchup is the dominant term in American English and Canadian English, although catsup is commonly used in some southern US states and Mexico.[26]

In Canada and the US, tomato sauce is not a synonym for ketchup but is a sauce made from tomatoes and commonly used in making sauce for pasta.[27]


The etymology of the word ketchup is unclear and has multiple competing theories:[28]

Amoy theory

A popular folk etymology is that the word came to English from the Cantonese 茄汁 (ke2 zap1, literally meaning 'tomato sauce' in Cantonese).[29] The character means 'eggplant'; tomato in Cantonese is 番茄, which literally translates to 'foreign eggplant'.

Another theory among academics is that the word derives from one of two words from Hokkien of the Fujian region of coastal southern China: kôe-chiap (in the Amoy/Xiamen dialect and Quanzhou dialect) or kê-chiap[30][31] (in the Zhangzhou dialect). Both of these pronunciations of the same word (膎汁, kôe-chiap / kê-chiap) come from the Quanzhou dialect, Amoy dialect, and Zhangzhou dialect of Hokkien respectively, where it meant the brine of pickled fish or shellfish (, 'pickled food' (usually seafood) + , 'juice'). There are citations of koe-chiap in the Chinese-English Dictionary of the Vernacular or Spoken Language of Amoy (1873) by Carstairs Douglas, defined as "brine of pickled fish or shell-fish".[32]

Malay theory

Ketchup may have entered the English language from the Malay word kicap (pronounced [kitʃap], sometimes spelled kecap or ketjap). Originally meaning 'soy sauce', the word itself derives from Chinese.[33]

In Indonesian cuisine, which is similar to Malay, the term kecap refers to fermented savory sauces. Two main types are well known in their cuisine: kecap asin which translates to 'salty kecap' in Indonesian (a salty soy sauce) and kecap manis or 'sweet kecap' in Indonesian. Kecap manis is a sweet soy sauce that is a mixture of soy sauce with brown sugar, molasses, garlic, ginger, anise, coriander and a bay leaf reduced over medium heat until rather syrupy. A third type, kecap ikan, meaning 'fish kecap' is fish sauce similar to the Thai nam pla or the Philippine patis. It is not, however, soy-based.

European-Arabic theory

American anthropologist E. N. Anderson relies on Elizabeth David to claim that ketchup is a cognate of the French escaveche, meaning 'food in sauce'.[34] The word also exists in Spanish and Portuguese forms as escabeche, 'a sauce for pickling', which culinary historian Karen Hess traced back to Arabic kabees, or 'pickling with vinegar'. The term was anglicized to caveach, a word first attested in the late 17th century, at the same time as ketchup.[28]

Early uses in English

Blue Label Tomato Ketchup advertisement, Curtice Brothers, 1898

The word entered the English language in Britain during the late 17th century, appearing in print as catchup (1690) and later as ketchup (1711). The following is a list of early quotations collected by the Oxford English Dictionary.


U.S. Heinz tomato ketchup's ingredients (listed from highest to lowest percentage weight) are: tomato concentrate from red ripe tomatoes, distilled vinegar, high-fructose corn syrup, corn syrup, salt, spice, onion powder, and natural flavoring.[36]

"Fancy" ketchup

Some ketchup in the U.S. is labeled "Fancy", a USDA grade related to specific gravity. Fancy ketchup has a higher tomato solid concentration than other USDA grades.[37]

USDA ketchup grades
Grade Specific gravity Total solids
Fancy 1.15 33%
Extra Standard 1.13 29%
Standard 1.11 25%


The following table compares the nutritional value of ketchup with raw ripe tomatoes and salsa, based on information from the USDA Food Nutrient Database.[38]

(per 100 g)
Ketchup Low-sodium
USDA commodity
Energy 419 kJ
100 kcal
435 kJ
104 kcal
75 kJ
18 kcal
150 kJ
36 kcal
Water 68.33 g 66.58 g 94.50 g 89.70 g
Protein 1.74 g 1.52 g 0.88 g 1.50 g
Fats 0.49 g 0.36 g 0.20 g 0.20 g
Carbohydrates 25.78 g 27.28 g 3.92 g 7.00 g
Sodium 1110 mg 20 mg 5 mg 430 mg
Vitamin C 15.1 mg 15.1 mg 12.7 mg 4 mg
Lycopene 17.0 mg 19.0 mg 2.6 mg n/a


Transferring ketchup between plastic bottles

Commercial tomato ketchup has an additive, usually xanthan gum, which gives the condiment a non-Newtonian, pseudoplastic or "shear thinning" property – more commonly known as thixotropic.[citation needed] This increases the viscosity of the ketchup considerably with a relatively small amount added—usually 0.5%—which can make it difficult to pour from a container. However, the shear thinning property of the gum ensures that when a force is applied to the ketchup it will lower the viscosity enabling the sauce to flow. A common method to getting ketchup out of the bottle involves inverting the bottle and shaking it or hitting the bottom with the heel of the hand, which causes the ketchup to flow rapidly. Ketchup in plastic bottles can be additionally manipulated by squeezing the bottle, which also decreases the viscosity of the ketchup inside. Another technique involves inverting the bottle and forcefully tapping its upper neck with two fingers (index and middle finger together). Specifically, with a Heinz ketchup glass bottle, one taps the 57 circle on the neck. This helps the ketchup flow by applying the correct shearing force.[39] These techniques work because of how pseudoplastic fluids behave: their viscosity (resistance to flow) decreases with increasing shear rate. The faster the ketchup is sheared (by shaking or tapping the bottle), the more fluid it becomes. After the shear is removed the ketchup thickens to its original viscosity.

Ketchup is a non-Newtonian fluid, meaning that its viscosity changes under stress and is not constant. It is a shear thinning fluid which means its viscosity decreases with increased shear stress.[40] The equation used to designate a non-Newtonian fluid is as follows: . This equation represents apparent viscosity where apparent viscosity is the shear stress divided by shear rate. Viscosity is dependent on stress. This is apparent when you shake a bottle of tomato sauce/ketchup so it becomes liquid enough to squirt out. Its viscosity decreased with stress.[41]

Graph representation of the three main fluid viscosity categories

The molecular composition of ketchup is what creates its pseudoplastic characteristics. Small polysaccharides, sugars, acids, and water make up the majority of the metastable ketchup product, and these small structures are able to move more easily throughout a matrix because of their low mass. While exposed to shear stress, the molecules within the suspension are able to respond quickly and create an alignment within the product.[42] The bonds between the molecules are mostly hydrogen bonds, ionic interactions, and electrostatic interactions, all of which can be broken when subject to stress. Hydrogen bonds are constantly rearranging within a product due to their need to be in the lowest energy state, which further confirms that the bonds between the molecules will be easily disrupted. This alignment only lasts for as long as shear stress is applied. The molecules return to their original disorganized state once the shear stress dissipates.[42]

In 2017, researchers at the Massachusetts Institute of Technology reported the development of a bottle coating that allowed all the product to slip out without leaving a residue.[43]

In 2022, researchers at the University of Oxford found that splatter from a near-empty bottle can be prevented by squeezing more slowly and doubling the diameter of the nozzle.[44]


Ketchup is one of the many products that are leachable, meaning that the water within the product migrates together as the larger molecules within the product sediment, ultimately causing water to separate out. This forms a layer of water on top of the ketchup due to the molecular instability within the product.[45] This instability is caused by interactions between hydrophobic molecules and charged molecules within the ketchup suspension.

Pectin is a polysaccharide within tomatoes that has the ability to bind to itself and to other molecules, especially water, around it. This enables it to create a gel-like matrix, dependent on the amount within the solution. Water is a large part of ketchup, due to it being 80% of the composition of distilled vinegar. In order for the water within the ketchup to be at the lowest possible energy state, all of the hydrogen bonds that are able to be made within the matrix must be made.[46] The water bound to the polysaccharide moves more slowly within the matrix, which is unfavorable with respect to entropy.[45] The increased order within the polysaccharide-water complex gives rise to a high-energy state, in which the water will want to be relieved. This concept implies that water will more favorably bind with itself because of the increased disorder between water molecules. This is partially the cause for water leaching out of solution when left undisturbed for a short period of time.

See also


  1. ^ Charles, Dan (2 September 2019). "Meet The Man Who Guards America's Ketchup". National Public Radio. Retrieved 3 September 2019.
  2. ^ Smith, Andrew F. (1996). Pure Ketchup: A History of America's National Condiment, with Recipes. University of South Carolina Press. p. 17. ISBN 978-1-57003-139-7.
  3. ^ "Ketchup: A Saucy History". History. 20 July 2012. Archived from the original on 2 April 2018. Retrieved 15 March 2013.
  4. ^ Thomas, Pat (23 November 2010). "Behind the Label: Tomato Ketchup". The Ecologist. Archived from the original on 14 July 2014. Retrieved 8 July 2014.
  5. ^ David, Javier E. (15 February 2013). "The Ketchup War that Never Was: Burger Giants' Link to Heinz". Retrieved 11 March 2017.
  6. ^ Chu, Louisa (29 August 2019). "Who Makes the Best Ketchup Chips? Yes, They're a Thing. and We Tried 13 Brands from Canada". Chicago Tribune. Retrieved 7 February 2021.
  7. ^ Cooke, Mordecai Cubitt (1891). British Edible Fungi. London: Kegan Paul, Trench, Trübner & Company Limited. pp. 201–206.
  8. ^ Bell, Annie (5 June 1999). "Condiments to the Chef". The Independent. Retrieved 10 September 2014.
  9. ^ Branston, Thomas F. (1857). The Hand-Book of Practical Receipts of Every-Day Use. Philadelphia: Lindsay & Blakiston. pp. 148–149.
  10. ^ Smith, Andrew F. (1996). Pure Ketchup: A History of America's National Condiment, with Recipes. Columbia, South Carolina: University of South Carolina Press. pp. 16–17. ISBN 1-57003-139-8.
  11. ^ a b c Jurafsky, Dan (30 May 2012). "The Cosmopolitan Condiment: An Exploration of Ketchup's Chinese Origins". Archived from the original on 2 February 2015. Retrieved 30 January 2015.
  12. ^ "Ketchup". Oxford English Dictionary. Retrieved 22 October 2021.
  13. ^ Skrabec, Quentin R. Jr. (2009). H. J. Heinz: A Biography. Jefferson, NC: McFarland & Co. p. 56. ISBN 978-0-78645332-0.
  14. ^ Skrabec, Quentin R. Jr. (2009). H. J. Heinz: A Biography. Jefferson, NC: McFarland & Co. p. 57. ISBN 978-0-78645332-0.
  15. ^ "Heinz - History". Heinz. Archived from the original on 20 July 2011. Retrieved 27 July 2011.
  16. ^ Rozin, Elisabeth (1994). The Primal Cheeseburger. New York: Penguin Books. ISBN 978-0-14-017843-2.
  17. ^ "Tomato History: From Poison to Obsession". Archived from the original on 13 June 2011. Retrieved 26 May 2011.
  18. ^ Casey, Kathy (2004). Retro Food Fiascos: A Collection of Curious Concoctions. Portland: Collectors Press. p. 128. ISBN 978-1-888054-88-0.
  19. ^ Santich, Barbara (2012). Bold Palates: Australia's Gastronomic Heritage. Kent Town, South Australia: Wakefield Press. ISBN 978-1-74305-094-1.
  20. ^ Smith, Andrew F. (2013). The Oxford Encyclopedia of Food and Drink in America (2nd ed.). New York, New York: Oxford University Press. p. 54. ISBN 978-0-19-973496-2.
  21. ^ Gladwell, Malcolm (2009). What the Dog Saw and Other Adventure Stories. New York: Little, Brown & Co. p. 41.
  22. ^ Smith, Andrew F. (2001). The Tomato in America: Early History, Culture, and Cookery. Urbana: University of Illinois Press. ISBN 0-252-07009-7.
  23. ^ Nassauer, Sarah (19 September 2011). "Old Ketchup Packet Heads for Trash". The Wall Street Journal. Retrieved 19 October 2012.
  24. ^ "Heinz Unveils New Blue Ketchup". Associated Press. 7 April 2003. Archived from the original on 17 April 2023.
  25. ^ "Consumer FAQs". Heinz. Archived from the original on 20 November 2008.
  26. ^ "Catsup vs Ketchup". Diffen. July 2014.
  27. ^ De Kleine, John (2009). Lots of Fat and Taste Recipes. Xlibris Corporation. p. 477. ISBN 978-1-4415-3096-7.
  28. ^ a b Smith, Andrew F. (2001). Pure Ketchup: A History of America's National Condiment. Washington, DC: Smithsonian Institution Press. p. 4. ISBN 1-56098-993-9. The etymological origin of the word ketchup is a matter of confusion
  29. ^ Chen, Anna (25 October 2014). "The Chinese in Britain: Personal Tales of a Journey to a New Land". South China Morning Post. Retrieved 16 December 2021.
  30. ^ Jurafsky, Dan (2 September 2009). "Ketchup". The Language of Food. Retrieved 10 November 2011.
  31. ^ "Ketchup". The American Heritage Dictionary of the English Language. Retrieved 16 December 2021.
  32. ^ Douglas, Carstairs (1873). Chinese-English Dictionary of the Vernacular or Spoken Language of Amoy. London: Presbyterian Church of England. pp. 242 & 46.
  33. ^ "Ketchup". Online Etymology Dictionary. Retrieved 8 December 2020.
  34. ^ Anderson, E. N. (1988). The Food of China. New Haven: Yale University Press. p. 160. ISBN 0-300-04739-8.
  35. ^ Mitchell, Christine M. (2010). "Book Review: The Handy Homemaker, Eighteenth-Century Style" (PDF). JASNA News. No. Spring 2010. Archived from the original (PDF) on 10 October 2010. Retrieved 26 March 2015.
  36. ^ "Ketchup – Tomato Ketchup". Heinz Ketchup. Archived from the original on 14 December 2016. Retrieved 15 December 2016.
  37. ^ Barrett, Diane M.; Garcia, Elisabeth; Wayne, Jo Ellen (1998). "Textural Modification of Processing Tomatoes" (PDF). Critical Reviews in Food Science and Nutrition. 38 (3): 173–258. doi:10.1080/10408699891274192. PMID 9595227.
  38. ^ "National Nutrient Database for Standard Reference". USDA. Retrieved 3 December 2007.
  39. ^ "What's the Best Way to Get Heinz® Ketchup out of the Iconic Glass Bottle?". Archived from the original on 5 November 2012. Retrieved 5 November 2012.
  40. ^ "Non-Newtonian Fluids". Science Learning Hub. 12 April 2010. Archived from the original on 13 October 2016. Retrieved 12 October 2016.
  41. ^ "Shear Mystery". NASA. 7 June 2002. Archived from the original on 13 October 2016. Retrieved 12 October 2016.
  42. ^ a b Coupland, John N. (2014). An Introduction to the Physical Chemistry of Food. New York, New York: Springer. p. 128. ISBN 978-1-4939-0761-8.
  43. ^ Ghosh, Pallab (22 February 2017). "Slippery Bottle Solves Ketchup Problem". BBC News. Retrieved 7 March 2017.
  44. ^ "Oxford scientists crack case of why ketchup splatters from near-empty bottle". 24 November 2022.
  45. ^ a b Vilgis, T. (1893). "Nineteen: "Ketchup as Tasty Soft Matter"". The Kitchen as Laboratory: Reflections on the Science of Food and Cooking. New York: Columbia University Press. pp. 142–145.
  46. ^ Journel, André G.; Deutsch, Clayton V. (1993). "Entropy and Spatial Disorder". Mathematical Geology. 25 (3): 329–355. Bibcode:1993MatGe..25..329J. doi:10.1007/BF00901422. S2CID 122572917.

Further reading