Pickling lime, also known as calcium hydroxide or hydrated lime, is a chemical compound used for making pickles crisp and firm. When used properly, pickling lime is safe and effective. However, some people wonder if pickling lime can go bad or lose its potency over time. Here’s a comprehensive look at whether or not pickling lime can go bad.
What is Pickling Lime?
Pickling lime is a white powder made by combining calcium oxide (also known as quicklime) with water. This produces a chemical reaction that turns the quicklime into calcium hydroxide. The terms “pickling lime” and “calcium hydroxide” are used interchangeably.
Pickling lime has a few key characteristics:
- It has a very alkaline pH, usually around 12-13
- It is slightly soluble in water
- It produces heat when combined with water due to the chemical reaction
- It has a bitter, unpleasant taste
In pickling, calcium hydroxide serves a few important purposes:
- It firms up vegetables by promoting pectin formation
- It helps maintain crisp texture
- It preserves crunchiness
- It increases acidity of pickling liquid
Without the use of pickling lime or a similar firming agent, many vegetables would turn mushy during the pickling process. The calcium ions from the lime crosslink with pectin in the veggie cell walls. This forms calcium pectate, which adds structure and firmness.
Does Pickling Lime Go Bad?
Pickling lime is an alkaline chemical compound that does not spoil, go bad, or lose its potency as time passes. Properly stored pickling lime has an indefinite shelf life. Here are some key points about the shelf life of pickling lime:
- Pickling lime remains effective when stored in an airtight container in a cool, dry place.
- It does not lose potency or expire when stored for years.
- Old and freshly purchased pickling lime generally have the same firming power.
- As long as it has not gotten wet and turned into a solid clump, old pickling lime will still work.
The main thing that can make pickling lime less effective is exposure to moisture. If the powder gets wet, it will slowly turn into a solid mass as the calcium hydroxide reacts with carbon dioxide in the air. At this point, it becomes difficult to accurately measure quantities for recipes.
As long as you store calcium hydroxide in an airtight container in a cool, dry place, it will remain usable indefinitely. There is no need to worry about old pickling lime going bad or losing its firming abilities.
Using Old Pickling Lime
Pickling lime that is a few years old but still in powdered form is perfectly safe to use. Here are some tips for getting the most out of old pickling lime:
- Give it a stir or shake before measuring to distribute any clumps.
- You may need to use a bit more than a recipe calls for if it’s been open for several years.
- Add it to the pickle brine slowly while stirring to help it dissolve.
- Be sure to thoroughly rinse vegetables after the soaking period.
The main drawback of very old pickling lime is that it may not fully dissolve in a brine. But even if not all the powder dissolves, it will still provide adequate firming power. With extra stirring, you can get old pickling lime to properly dissolve again.
Signs of Spoiled Pickling Lime
While pickling lime itself does not spoil, sometimes problems with storage can cause it to become unusable. Here are some signs that pickling lime has gone bad and should be discarded:
- Solid clumps or blocks – Pickling lime that has gotten wet and hardened into a solid clump will not powderize again. At this point it can not be accurately measured for recipes.
- Grayish tone – Pickling lime that has been exposed to a lot of moisture may start to turn grayish rather than bright white. This means it has partially turned to calcium carbonate and calcium hydroxide.
- Mold growth – If you see mold growing on the surface of the powder, it should be tossed. Mold indicates moisture exposure.
- Loss of potency – In very rare cases, pickling lime that has gotten wet multiple times may lose some firming power. If your pickles still turn out mushy after using the lime, it may need to be replaced.
As long as you store pickling lime in an airtight container in a dry location, it should remain potent and usable indefinitely. Any signs of moisture exposure mean it’s time to get fresh pickling lime.
Frequently Asked Questions
Can pickling lime absorb moisture from the air?
Yes, calcium hydroxide can slowly absorb moisture from the air, especially if it is stored in a humid environment. This is why it’s important to keep pickling lime in an airtight container. Even a brief exposure to air can allow it to start absorbing moisture and hardening.
Does pickling lime have an expiration date?
No, pickling lime does not come with an expiration date or have a definitive shelf life. As long as it is stored properly in an airtight container, it will remain effective indefinitely. Avoid using pickling lime that shows signs of moisture damage or mold growth.
Can expired pickling lime make you sick?
No, expired or old pickling lime cannot make you sick. Even if it has turned into solid clumps or blocks, it is still calcium hydroxide and will not cause illness if consumed. The worst that can happen is it will not be as effective at firming up pickles properly.
How should you store pickling lime?
Pickling lime should be stored in an airtight container, like a sealed plastic tub or mason jar. Keep it in a cool, dry place away from moisture and heat. As long as no moisture gets in, it will remain fresh and usable. Only open the container when you need to remove some for a recipe.
Does humidity affect pickling lime?
Yes, humidity can damage pickling lime over time. Calcium hydroxide absorbs moisture from the air, so storage in a humid environment can cause clumping and hardening. Store pickling lime in an area with low humidity for best results and maximum shelf life.
Can you test old pickling lime to see if it still works?
Unfortunately there is no good way to test pickling lime to check its potency. Since it does not actually expire or lose firming power, the only thing that makes it unusable is moisture damage. Check for signs of moisture exposure like clumping and mold growth. If it still appears as a dry powder, it should still work fine in recipes.
Is pickling lime dangerous to handle?
Dry pickling lime powder can irritate the skin, eyes, nose and throat. Always use care when handling it. Wear gloves and eye protection, and avoid breathing in the dust. Be sure to thoroughly wash produce treated with pickling lime before consumption.
Can you reuse pickling lime?
It’s not recommended to reuse pickling lime. Calcium hydroxide is inexpensive, so you’re better off using fresh lime each time. Reusing pickling lime runs the risk of contamination and inconsistent results.
The Bottom Line
Pickling lime is a stable alkaline compound that, when stored properly, does not spoil or lose effectiveness over time. As long as it remains dry and powdery, calcium hydroxide can be kept indefinitely and used whenever needed. Just be sure to keep it in an airtight container in a cool, dry place. Any evidence of moisture means it’s time to replace your pickling lime with a fresh supply.
