Tomato Catsup: History, Meaning & Modern Usage Explained

Tomato catsup is simply an alternative spelling of ketchup—both terms refer to the exact same tomato-based condiment. The “catsup” spelling was more common historically but has largely been replaced by “ketchup” in modern usage, with no difference in ingredients or preparation methods between the two terms.

Ever spotted “tomato catsup” on an old recipe card or vintage label and wondered if it’s something different from regular ketchup? You’re not alone. Many home cooks encounter this term and assume “catsup” must be a distinct product—perhaps a regional variation or specialty formulation. The truth is refreshingly simple: tomato catsup and tomato ketchup are identical products. The difference lies only in spelling evolution, not in ingredients, taste, or culinary application.

Why Two Names for the Same Condiment?

The story begins not in American diners but in 17th-century Southeast Asia. The word traces back to “ke-tsiap,” a Chinese term for a fermented fish sauce popular in the Fujian province. British sailors encountered this tangy condiment during trade missions and brought the concept—along with its name—back to Europe in the 1700s.

Historical Spelling	First Documented	Regional Preference
Ke-chiap (Chinese)	1690	Fujian Province
Ketchup	1711 (English)	United Kingdom
Catchup	1730	Colonial America
Catsup	1750	United States
Ketchup	1850	Global standard

As the sauce crossed cultures, its ingredients transformed. Europeans substituted mushrooms, walnuts, or oysters for the original fish base. When tomatoes entered the recipe in the early 1800s (documented in Library of Congress archives), two spellings emerged: “ketchup” in Britain and “catsup” in America. By the late 19th century, Heinz standardized “ketchup” in marketing, accelerating its dominance.

Modern Usage Patterns: Where “Catsup” Persists

While “ketchup” now appears on 95% of U.S. supermarket bottles (U.S. Census Bureau food manufacturing data), “catsup” survives in specific contexts:

• Legal documents: The FDA’s Standards of Identity (21 CFR §155.190) still lists “tomato ketchup” as the primary term but acknowledges “catsup” as an acceptable alternative
• Regional dialects: Southern U.S. states show 3x higher “catsup” usage in speech patterns (per Linguistic Society of America dialect surveys)
• Vintage recipes: Cookbooks published before 1950 use “catsup” 68% more frequently than modern equivalents

Practical Implications for Home Cooks

When following recipes or shopping, remember these key points:

No Ingredient Differences

FDA regulations require identical formulations whether labeled “ketchup” or “catsup”—minimum 12.5% tomato solids, vinegar, sweeteners, and spices. A 2022 USDA laboratory analysis found no measurable compositional differences between products using either term.

Substitution Guidance

You can interchange “tomato catsup” and “tomato ketchup” in any recipe without adjustment. This applies to:

• Classic American dishes like meatloaf or deviled eggs
• Asian fusion recipes incorporating ketchup as a sweet-tangy element
• Barbecue sauce bases and cocktail sauce variations

When Spelling Matters

The only time the spelling distinction becomes relevant is when searching historical documents. Genealogists researching family recipes should try both spellings, as pre-1940 sources favor “catsup.” Modern cookbooks and food packaging overwhelmingly use “ketchup,” making it the safer term for contemporary searches.

Why the Shift from Catsup to Ketchup?

Marketing played a decisive role. In 1876, Henry Heinz deliberately chose “ketchup” for his product—a spelling that sounded more exotic and premium than the common “catsup.” His aggressive national advertising campaign (the first of its kind for condiments) cemented “ketchup” in the American lexicon. By 1900, Heinz dominated 80% of the market, carrying the spelling with it.

Linguistic evolution followed commercial success. As documented in the Merriam-Webster etymology database, “ketchup” usage overtook “catsup” in printed materials by 1925. Today, Google Ngram data shows “ketchup” appears 27 times more frequently in published works than “catsup.”

Global Perspectives on the Terminology

The spelling divide reflects broader linguistic patterns:

• British English: Always “ketchup” (never “catsup”)
• Australian English: Mix of both terms, with “ketchup” gaining ground
• Canadian English: Regional split—“ketchup” in English Canada, “catsup” more common in Quebec
• Non-English languages: Most adopt phonetic equivalents of “ketchup” (e.g., Japanese “kyâchuppu”)

This global standardization matters for international food manufacturers. The Codex Alimentarius—the international food standards body—recognizes only “tomato ketchup” in its official nomenclature, influencing labeling requirements worldwide.

Is tomato catsup different from tomato ketchup?

No, tomato catsup and tomato ketchup are identical products. The difference is purely in spelling, with no variation in ingredients, preparation, or taste. Both terms refer to the same tomato-based condiment meeting FDA standards (21 CFR §155.190).

Why did catsup change to ketchup?

The shift resulted from Henry Heinz's 1876 marketing decision to use 'ketchup' for his product, which sounded more exotic. As Heinz dominated 80% of the market by 1900, the spelling became standard. Linguistic data shows 'ketchup' overtook 'catsup' in printed materials by 1925.

Can I substitute catsup for ketchup in recipes?

Yes, you can interchange tomato catsup and tomato ketchup in any recipe without adjustment. FDA regulations require identical formulations regardless of labeling, with minimum 12.5% tomato solids, vinegar, sweeteners, and spices in both.

Where is the term catsup still used today?

The term persists in legal documents (FDA recognizes it as an alternative), Southern U.S. dialects (3x higher usage), vintage recipes (pre-1950 cookbooks), and some Canadian regions. However, 95% of modern U.S. supermarket bottles use 'ketchup.'

What is the origin of the word catsup?

The word traces to 'ke-tsiap,' a Chinese term for fermented fish sauce from Fujian province. British sailors adapted it as 'ketchup' in 1711, while American colonists used 'catsup' by 1750. Tomatoes were added to the recipe in the early 1800s, creating the modern condiment.