When Did They Start Putting Nitrates in Bacon?

January 8, 2026 •

2 min read

Records indicate ancient civilizations were preserving meat with salt as early as 3000 BCE, but the practice of adding pure nitrates in bacon is a much more recent, modern development driven by scientific discovery. It wasn't until the late 19th century that the specific role of nitrates and nitrites in curing was understood, transitioning the process from folk art to a controlled science.

Quick Summary

Nitrates were not intentionally added to bacon until the late 1800s, when scientists discovered that the ingredient responsible for curing was actually nitrite, created by bacteria acting on naturally contaminated saltpeter. This led to the controlled, direct addition of nitrites and nitrates to improve safety and consistency.

Key Points

Ancient Use: Accidental exposure began with salt naturally contaminated with saltpeter.
19th-Century Discovery: Scientists found nitrites from saltpeter caused curing and pink color.
Early 20th-Century Control: Direct addition of purified sodium nitrite started for consistency.
1925 Regulation: USDA approved sodium nitrite for curing.
Nitrosamine Concerns: 1970s regulations required inhibitors to counter formation during cooking.
"Uncured" Misconception: Products use natural nitrate sources but still contain the active curing agent.

The Ancient Roots of Curing with Saltpeter

Meat preservation was crucial before refrigeration. Ancient civilizations used salt, and later, during the Middle Ages, meat curers in Europe discovered that salt containing saltpeter (potassium nitrate) worked exceptionally well. This contaminated salt prolonged preservation and gave meat a desirable reddish-pink color, though the reasons weren't understood at the time.

The Nineteenth-Century Scientific Revelation

The turning point came in the late 1800s when scientific investigation revealed the underlying chemistry of curing. Researchers discovered that bacteria on the meat converted nitrate from saltpeter into nitrite, which was the actual active curing agent. The discovery highlighted nitrite's benefits, including preventing botulism, developing characteristic cured meat flavor, producing the pink color, and protecting against rancidity.

The Rise of Controlled Curing and USDA Regulations

Understanding nitrite's role led to the direct addition of purified sodium nitrite in the early 20th century for better control, consistency, and safety. The USDA authorized its use in 1925, and later regulations mandated adding inhibitors like sodium ascorbate to counter nitrosamine concerns during cooking.

Traditional vs. Modern Curing Methods

Bacon curing varies:


Feature	Traditional Curing (Dry-Cured)	Modern Curing (Pumped/Wet-Cured)
Nitrate/Nitrite Source	Historically from saltpeter; now may use purified nitrates or natural sources.	Uses purified sodium nitrite and sodium nitrate.
Application	Dry cure rubbed.	Injected brine.
Curing Time	Longer.	Shorter.
End Product	Often artisanal.	Mass-produced, consistent.
Labeling	May be "uncured".	Labeled "cured".

The "Uncured" Labeling Misconception

"Uncured" bacon uses natural sources like celery powder, not synthetic ones, but still contains the same active curing agent after bacterial conversion.

Conclusion: From Mystery to Regulation

Nitrates were inadvertently used in ancient curing with saltpeter. Intentional, controlled addition began in the late 19th/early 20th centuries following discoveries about nitrites. Regulated by the USDA since 1925, their use remains key for safety and quality.

Frequently Asked Questions

Nitrate ($NO_3$) is the precursor to nitrite ($NO_2$). Bacteria convert nitrate to nitrite, the active curing agent responsible for preservation, flavor, and color.

Saltpeter, or potassium nitrate, was used because it was a known preservative, often an impurity in salt, effective at preserving and giving meat a pink color.

In the U.S., the USDA began regulating and authorizing the use of sodium nitrite in meat curing in 1925.

No. "Uncured" means natural sources like celery powder are used instead of synthetic sodium nitrite. These natural nitrates are still converted to nitrites to cure the meat.

Since the 1970s, inhibitors like sodium ascorbate (vitamin C) are added, required by the USDA, to reduce the formation of nitrosamines when bacon is cooked at high temperatures.

No. Regulations for nitrites and nitrates vary by country and region, differing from U.S. USDA rules.

Yes, but these methods offer less protection against Clostridium botulinum. Many "uncured" products use natural sources and fermentation to achieve similar results and safety.