The Science Behind Morton's Salty Reputation
At a fundamental level, all pure salt is sodium chloride ($NaCl$), and the concentration of sodium by weight is consistent across brands. So, a pound of Morton table salt contains the same amount of sodium as a pound of any other pure salt. The key factor is how that salt is measured and what its crystalline structure is. Most home cooks measure salt using volume, like a teaspoon or tablespoon, where density becomes a critical factor.
Crystal Shape and Density: A Tale of Two Kosher Salts
The most dramatic illustration of this phenomenon is the comparison between Morton Kosher Salt and Diamond Crystal Kosher Salt. The two brands use different methods to form their crystals, leading to stark differences in density.
Morton manufactures its kosher salt by using high-pressurized rollers to flatten cubic salt granules into large, thin, and dense flakes. This process creates a flake that is heavier per teaspoon because less air is trapped between the grains. In contrast, Diamond Crystal uses a patented pan-evaporation method called the Alberger process, which results in hollow, pyramid-shaped, and relatively delicate crystals. These flakes occupy more space by volume, so a teaspoon of Diamond Crystal salt will have significantly less sodium chloride by weight. Food and Wine notes that a ¼-teaspoon measurement of Morton contains 480 milligrams of sodium, while the same volume of Diamond Crystal contains only 280 milligrams. This difference means a recipe is approximately 58% saltier when using Morton over Diamond Crystal, assuming a straight volume substitution.
The Perception of Saltiness and Volume Measurement
The human perception of saltiness is directly linked to the concentration of sodium ions dissolving on the tongue's taste receptors. When measuring salt by volume, the denser the crystals, the more sodium is packed into that volume. Because most recipes are written for volume measurements (e.g., "1 tsp kosher salt"), cooks who switch brands without adjusting quantities will notice a significant difference in flavor intensity. The larger, lighter crystals of Diamond Crystal dissolve more quickly, allowing for easier adjustment during seasoning, while Morton's denser flakes take longer to disperse, increasing the risk of over-seasoning.
How Morton Salt Is Made: The Vacuum Evaporation Method
Morton Salt's primary method for producing table and kosher salt is a highly controlled process called vacuum evaporation, also known as solution mining. This technique yields a product with very high purity and a specific, dense crystal structure.
Here is a step-by-step breakdown of the process:
- Brine Production: Water is injected into ancient, underground salt deposits, dissolving the salt and creating a highly concentrated brine.
- Pumping to the Surface: The saturated brine solution is then pumped to the surface from deep underground.
- Vacuum Evaporation: The brine is boiled in a series of sealed vacuum pans. Lowering the pressure reduces the boiling point of the water, allowing for more efficient, rapid evaporation.
- Crystal Formation: As the water evaporates, pure salt crystals form and fall to the bottom of the pan as a slurry.
- Finishing: The resulting salt is then dried and processed. For kosher salt, these vacuum-evaporated cubes are pressed into thin, dense flakes by high-pressure rollers.
Additives and Other Factors Influencing Saltiness
Morton table salt, unlike its kosher counterpart, often contains additives that do not affect the saltiness but are crucial for its free-flowing properties. Iodized salt includes potassium iodide as a dietary supplement, a practice started in the 1920s to combat iodine deficiency. Anti-caking agents, such as calcium silicate, are also added to prevent clumping, which is the origin of the brand's famous slogan, "When it rains, it pours". For perception, crystal size, not additives, is the dominant factor.
The Role of Taste Receptors
The mechanism of salt taste perception is primarily linked to epithelial sodium channels (ENaCs) on the tongue's taste buds, which allow sodium ions to enter receptor cells. The speed at which salt crystals dissolve and release these ions directly influences the intensity and duration of the salty taste. Smaller, finer grains, like those in table salt, dissolve instantly, delivering a quick, sharp burst of flavor. Coarser salts, including many kosher and sea salts, dissolve more slowly, providing a more gradual release of saltiness. This is a subtle yet important factor contributing to overall taste perception.
Morton Salt Compared to Other Varieties
| Feature | Morton Kosher Salt | Diamond Crystal Kosher Salt | Standard Table Salt |
|---|---|---|---|
| Crystal Shape | Dense, compacted flakes | Hollow, pyramidal flakes | Small, uniform cubes |
| Density | Higher (heavier by volume) | Lower (lighter by volume) | Very high (densest) |
| Sodium by Volume | High (480 mg/¼ tsp) | Low (280 mg/¼ tsp) | Highest (590 mg/¼ tsp) |
| Manufacturing | Solution mining, vacuum evaporation, roller-pressed | Alberger pan evaporation | Solution mining, vacuum evaporation |
| Additives | Typically none | Typically none | Often includes anti-caking agents and iodine |
| Best Use Case | Salting meats, pickling (adjust volume) | General seasoning, baking (more forgiving) | Baking (quick dissolution), seasoning on plates |
Conclusion: The Saltiness Is in the Structure
Ultimately, the sensation of ``why is Morton salt so salty?'' is a misunderstanding of density versus chemistry. Morton salt is not chemically different from other pure sodium chloride salts, but its manufacturing process creates a crystal shape that is significantly denser than other brands, especially Diamond Crystal kosher salt. This means that when you measure by volume, you are adding more actual salt to your food, resulting in a more intense flavor. For consistent results, especially in baking, measuring salt by weight is the most reliable method. The science is clear: the difference in taste is not in the sodium content itself, but in how it is delivered to the palate. For more on the science of flavor, consult expert resources like those from the National Institutes of Health.
The Difference in Taste Perception
Beyond just density, several other elements contribute to how we perceive the saltiness of different salts. These factors include:
- Dissolution Rate: The rate at which the salt crystals dissolve on the tongue affects the speed and intensity of the salty flavor. Fine table salt dissolves quickly, delivering an immediate punch of salt, while larger, coarser crystals dissolve more slowly, providing a more prolonged salty sensation.
- ENaC Sensitivity: Individual genetic variations in epithelial sodium channels (ENaCs) mean that some people are more sensitive to saltiness than others, causing them to find foods excessively salty at levels others find normal.
- Complementary Flavors: Salt is a flavor enhancer that can mask bitter notes and boost sweet and savory flavors. In Morton's case, the higher concentration of sodium per volume can more effectively suppress bitterness or heighten other tastes, amplifying the overall perceived flavor profile.
- Hydration and Taste: The act of dissolving salt in saliva triggers a physiological response that can influence hydration and thirst. This complex interaction can further shape the overall tasting experience, making it more dynamic than a simple burst of flavor.
- Crystal Shape and Surface Area: Morton's denser, flaked crystals offer a different surface area-to-mass ratio compared to the hollow pyramids of Diamond Crystal. This textural difference affects how the salt adheres to food and dissolves, influencing how evenly flavor is distributed across the palate.
Conclusion: The Saltiness Is in the Structure
Ultimately, the sensation of ``why is Morton salt so salty?'' is a misunderstanding of density versus chemistry. Morton salt is not chemically different from other pure sodium chloride salts, but its manufacturing process creates a crystal shape that is significantly denser than other brands, especially Diamond Crystal kosher salt. This means that when you measure by volume, you are adding more actual salt to your food, resulting in a more intense flavor. For consistent results, especially in baking, measuring salt by weight is the most reliable method. The science is clear: the difference in taste is not in the sodium content itself, but in how it is delivered to the palate. For more on the science of flavor, consult expert resources like those from the National Institutes of Health.
