Curing Olives: Which Salt to Use and Why It Matters

Which Salt Should You Use for Curing Olives?

The answer—according to both culinary and food safety experts—is pickling salt. This recommendation is based on two critical factors:

• No Additives: Pickling salt contains no anti-caking agents or iodine, which can cloud the brine or alter the flavor, texture, and safety of the final product.
• Fast Dissolution: Its fine, uniform grains dissolve rapidly and completely, creating a stable, evenly dispersed salt solution.

Whether you're curing olives for the first time or continuing a cherished family tradition, choosing the right salt—and measuring it correctly—makes all the difference.

Why Measuring Salt Matters When Curing Olives

Curing olives is both a culinary craft and a food safety practice. At the heart of this process lies one crucial element: salt concentration.

Even small variations in salinity can mean the difference between a batch that ferments beautifully and one that molds or spoils. That’s because olives are a low-acid food, meaning they require precise brine conditions to prevent the growth of harmful bacteria, including Clostridium botulinum, the organism responsible for botulism.

🔗 Suggested source: UCANR’s Home Canning Guide or FDA Botulism Reference

A Real-World Example: When Salt Goes Wrong

A first time olive-brining customers contacted me after noticing problems with their olives: dark freckles on the skin, dull or brownish flesh, and, in some jars, visible mold. They had followed a widely used curing guide. So what went wrong?

The issue came down to how salt was measured.

The customer had used Diamond Crystal Kosher Salt, and while kosher salt both widely used and completely acceptable for curing olives, its large crystal size makes it much less dense than pickling salt so measuring it by volume (cups) instead of weight (grams or ounces) resulted in a dangerously weak brine—far below the recommended salinity. The batch of olives had to be discarded.

How Much Salt Is in a Pound?

We conducted tests using two different digital kitchen scales and two different salt brands:

• Pickling Salt (Morton’s): 1 pound = 1.75 cups
• Kosher Salt (Diamond Crystal): 1 pound = 3.5 cups

This variability underscores the central point: volume is inconsistent. Weight is accurate. Even within the same brand, compression during transport or storage can alter volume due to the crystalline nature of salt.

Weight vs. Volume in Brining: Why It Matters

Using too little salt leads to several risks:

• Microbial growth: Insufficient salt fails to inhibit pathogens, increasing spoilage risk.
• Texture problems: Salt controls bitterness and firmness. Too little = mushy olives.
• Failed fermentation: Beneficial bacteria struggle to thrive, leading to off flavors.
• Safety concerns: A weak brine can allow botulism-causing bacteria to multiply.

For these reasons, UC Davis and other land-grant institutions recommend a minimum 1 lb (454g) of salt per 1 gallon (3.8L) of water when curing olives.

Why Not Just Use a Cup?

Recipes that suggest "1 lb (1.5 cups)" as equivalent are misleading. That volume only applies to some pickling salts under ideal conditions. In reality, even pickling salt may require up to 1.75 cups per pound. For kosher salt, the volume needed can more than double.

The original UC guide in circulation repeats the “1.5 cups” volume error 23 times. While a corrected edition is forthcoming, we advise customers to ignore all volume-based references in favor of weighing salt.

Clarifying Terms: Curing vs. Preserving

The UC Guide draws an important distinction between two phases:

• Curing: The initial process of removing bitterness and softening the fruit via fermentation or lye processing.
• Preserving: A follow-up stage that may require a different (often stronger) brine to ensure long-term shelf stability.

This article focuses on salt brining during the curing phase. Always verify which phase your recipe or guide refers to—strength and duration of brine contact may vary.

Best Practices for Safe Olive Curing

• Weigh, don’t scoop: Always measure salt by weight using a kitchen scale.
• Know your salt: Pickling salt is the safest choice; kosher salt is acceptable only if properly weighed.
• Mix thoroughly: Ensure the salt fully dissolves before adding olives.
• Label your brine: Note the salt used, weight, and date.
• Taste test (optional): A proper brine should taste very salty but not harsh.
• When in doubt, throw it out: Any mold, discoloration, or odor means the batch must be discarded.

Conclusion: Salt Is the Backbone of Safe Curing

Salt may be a humble ingredient, but in the world of olive curing, it plays a leading role. Understanding its types, densities, and proper use ensures not only delicious olives—but also safe ones.

Frequently Asked Questions (FAQ)

What kind of salt should I use to cure olives?

Pickling or canning salt is ideal. It contains no additives and dissolves evenly for reliable and safe curing.

Can I use kosher salt instead of pickling salt?

Yes, but only if you weigh it. Kosher salt has lower density and cannot be substituted by volume.

Is it okay to measure salt in cups?

No. The same volume of salt can vary widely in weight. Always measure by weight for accuracy and safety.

What happens if I use too little salt?

You risk mold, spoilage, mushy texture, and in rare cases, serious illness like botulism. Don’t take shortcuts.

How much salt do I need for one gallon of water?

Use 1 pound of salt per gallon of water. That’s a 10% brine—standard for the curing phase.

Can I use iodized or flavored salt?

No. Additives can cloud the brine and alter flavor or texture. Stick with pure pickling or canning salt.

What should I do if my olives turn brown or show mold?

Discard the batch. Once spoilage appears, there’s no way to rescue it safely.