What is alum used for in pickling?

Alum is a powder-like substance that you may find in the spice section of grocery stores. You may have thought what this alum is. Alum is something that has a lot of uses in different aspects. For example, alum is a key ingredient in pickling. If you are curious about what is this, the history behind, what is alum used for in pickling, health concerns and other related things, you are at the right place. Here, in this article, we would like to cover all these topics. So, if you are curious to know more, please read through the whole article!

What is alum used for in pickling

What is an alum?

Alum is a chemical compound. It is actually any hydrated double sulfate of any metal. Alum tends to be crystal in nature and they are mostly transparent in color. This powder dissolves in the water. They also lose crystallite in heat and become liquid. Alums are sweet and acidic in taste. They have many uses and mostly in industrial uses. In recent times, they have become a common ingredient in the kitchen.

History of Alum

Alum is an ancient chemical which Egyptians used to use in dyeing textiles. Besides, the historians believed that Egyptian hardened papyruses with alum. Roman historian Pliny wrote about this alum as cosmetics as well as a medicine. People believed that alum was first used as a deodorant. In the 12th century alum was still a common element in medical application as well as in dyeing. Alum is mostly common in dry and desert regions. Furthermore, alum was imported from North Africa or regions around the Mediterranean Sea. In the 17th century, British developed a method for alum extraction. In the 19th century British baker started to use them in bread for better appearance. From the 2oth century baking soda became a competitor for alum but eventually alum won in the long run.

What is alum used for in pickling?

Though there exists different types of alum, potassium based alum is the slum people use for pickling. People use alum in pickling crisp cucumber or watermelon and to rind pickles also maraschino cherries.

Alum is a strong spice for pickling. The main purpose of alum in pickling is that it works as a preservative. It helps to maintain the crispiness of pickles. Also, it is a key ingredient in some play dough recipes.

How to use alum in pickling?

For traditional use alum and water are mixed together. Then, you should soak the cucumbers for 2 to 14 hours. Next you have to remove the excess lime absorbed by the cucumber. After that you need to remove the cucumber from the lime water and rinse it off. Also, store the pickled cucumber in the freshwater. Then, you have to repeat the rinsing and soaking process for 2 to 3 times. You need to be careful handling the pickles. The Aluminum ion in alum helps to make the cell of the fruits become sturdier and eventually the pickles become more firm and crispy.


Using alum in the final stage is not recommended.  If you still want to dip your pickles in the alum , be sure to remove all the residue. You should wash through with water and scrubs.

How much alum can you use for pickling?

You should never use the amount of one fourth teaspoon of alum. The pickling solution is per quart for this amount of alum.  Too much alum in pickling will leave a bitter taste. This is also harmful for the stomach.

Pros and cons of using alum in pickling

Alum is an ingredient that is common for pickling for a long time. Still, it has got some bad sides related to it.

Pros of using alum in pickling

Alum is that ingredient in pickling that gives the finished cucumber that firmness and satisfying crunch. As a result, the pickled cucumber tastes better. This firmness is very essential in the beginning stage. Since if the pickled cucumber gets softened at first, they will not be crispy and firm afterwards.

Cons of using alum in pickling

The main con of using alum in pickling is that many health experts in the USA said that it may be dangerous in high doses. But the food and drug administration of the USA still approves it. So, the main negative side is it has got health issues.

What can you use as a substitute for alum in pickling?

What can you use as a substitute for alum in pickling

The Alum powder is not in pickling for any flavor, rather it is here to make the pickles firm and crisp. But you can find some other ingredients such as lime, calcium chloride, Vitamin C powder, Ascorbic acid, cream of tartar, citric acid etc. We would like to give you an overview of comparison between alum and some of these.

Pickling lime vs. Alum

In southern pickle lime is a common firming agent. Lime absorbs into the tissue of fruits and vegetables’. Then it combines with the pectin of these to create calcium pectin. This ensures to keep the pickles firm. But they raise the pH of the pickles, so you should use them in the recipes they are called for. But like alum, pickling lime should also be removed from the pickles through repeated rinse..

Calcium Chloride/Pickle crisp vs. Alum

One of the most used ingredient as a substitute for alum is Calcium chloride. In recent year calcium chloride is available commercially as pickling crisp in the industry. The calcium chloride also works as a firming agent like alum. The main difference between calcium chloride and alum is in the taste. Alum provides an astringent flavor but the calcium chloride tastes saltier. The latter one tastes a lot saltier without adding any extra sodium.

Is it safe to use alum?

According to the USDA it is safe to use alum in pickling. Alum is safe to use for fermented cucumbers. But it does not improve the firmness of the pickles. So if you use ingredients of high quality to make pickles and follow the modern rules for canning, you can easily avoid alum.

Health concerns

Most of the food safety experts say that Alum is safe to consume in pickling. But ingestion of alum in 1 ounce that is 28.34 grams is deadly for any adult. People in the kitchen should be aware not to inhale alum powder or the fumes. The aluminum in alum is extremely toxic.

Cautions regarding using the alum

Cautions regarding using the alum

(1)       You should use the alum of high quality

  (2)        The fruits and vegetables’ for pickling must be fresh.

 (3)        Be sure to rinse off the final pickles to remove the remaining alum.

 (4)        Follow the instructions in the manual

(5)        Be sure to use the modern canning techniques.

(6)        You should never ever inhale alum powder

Final thoughts

In conclusion, we can say that alum is a frequent element in pickling. Alum has got many advantages related to this; still it has some bad points also. So it is advisable to avoid alum in the pickling process if possible. Still, if you want to use alum in pickling please be sure to follow the safety cautions.

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