Alum Powder Uses

Alum powder, also known as potassium alum, has been used for centuries for a variety of purposes.

Alum Powder Uses

This white mineral powder has many applications in cooking, skin care, oral hygiene, and even water purification.

What is Alum Powder?

Alum powder is made from a type of mineral salt called potassium aluminum sulfate. It has an astringent, sweet taste and can be found in the spice section of grocery stores, usually near the pickling ingredients.

The most common type of alum sold for household uses is potassium alum. This is a hydrated form of potassium aluminum sulfate with the chemical formula KAl(SO4)2∙12H2O.

There are a few other types of alum powder, including ammonium alum and soda alum. But potassium alum is the one most widely used in cooking, skin care, and other home applications.

Culinary Uses

One of the most popular uses of alum powder is as an ingredient in pickling recipes. The powder helps fruits and vegetables retain their crisp, firm texture during the pickling process. This is why alum is often called a "pickling spice."

Keeping Pickles Crisp

When fruits or veggies are submerged in an acidic pickling solution, their cell walls begin to lose integrity. The pectin holding the cell walls together starts to break down. This causes the produce to turn mushy.

Alum powder helps prevent this by reacting with the pectin. This protects and firms up the cell walls, ensuring your pickles, relishes, chutneys, and more stay crisp no matter how long they sit in the brine.

Most pickle recipes call for 1/4 to 1/2 teaspoon of alum per quart of pickling liquid. Simply add the powder to your vinegar brine before pouring it over your fresh produce. Overnight or up to 24 hours later, you'll have delightfully crunchy pickled goodies.

Fruit Preservative

In addition to pickles, alum powder has applications with fresh fruits. Sprinkling some on sliced apples, pears, peaches, and other delicate fruits slows down oxidation. This prevents them from turning brown when they are exposed to air.

Alum powder works similarly to lemon juice or vitamin C powder in this way. It maintains the fresh look of cut fruit, which is handy when you are preparing baked goods like pies, tarts, crumbles, and more.

About 1/8 teaspoon of alum per cup of sliced fruit does the trick. Toss the produce with the powder after slicing and before further prep or baking.

Baking Powder Ingredient

While best known as a pickling agent, alum powder has another role in baking. Alum powder serves as the acidic component in some brands of double-acting baking powder.

Tartaric acid or monocalcium phosphate usually fill this role instead. But using alum powder allows manufacturers to sell baking powder at a lower cost.

When mixed into doughs and batters, alum powder reacts with sodium bicarbonate (baking soda). This produces carbon dioxide bubbles that make quickbreads, cakes, fried foods, and more light and fluffy.

So while you may not add alum powder directly to your recipes, it can play an unseen role in helping your baked goods rise.

Skin Care Uses

In addition to being a versatile food ingredient, alum powder also has many applications as part of natural skin care routines. From tightening pores to treating razor burns, alum can improve the look and feel of your skin.

Skin Tightening & Exfoliation

The main reason alum powder is good for skin care is its astringent properties. As an astringent, alum causes proteins in the skin to temporarily contract. This makes pores smaller and gives the face a smoother, tightened look.

Making a paste from alum powder is an easy home remedy for shrinking enlarged pores or smoothing fine lines and wrinkles. Just mix it with a small amount of rose water then apply to clean skin for 5-10 minutes before rinsing.

This also gently exfoliates dead skin cells from the face. With continued use 2-3 times per week, you may see a reduction in acne scarring and age spots thanks to the mild peeling effects.

Aftershave Treatment

Another excellent use for alum powder is as a post-shave skin treatment for men. Those with sensitive skin prone to razor bumps and burns may benefit from applying this astringent powder.

Mix just a pinch of alum powder with water. Splash or rub this solution over your face after shaving. The alum will constrict blood vessels to stop bleeding from small nicks. It also fights bacteria to prevent infection.

With regular application, alum can improve the overall tone and texture of your skin. The minerals may also neutralize odor-causing bacteria to keep you smelling fresh too.

Oral Health Uses

A little-known benefit of alum powder is that it promotes oral health. Using this versatile powder can improve your oral hygiene and freshen your breath.

Reducing Bad Breath

One of the most obvious effects alum powder has is controlling bad breath. This is thanks to its antibacterial properties.

Dissolve a pinch of alum powder in warm water with a tiny bit of salt. Swish this solution around your mouth for 30 seconds to 1 minute before spitting it out. Don't swallow the liquid.

Use this simple yet effective oral rinse once or twice a day, especially first thing in the morning or after meals. Alum will kill odor-causing germs that build up on the tongue and around the gums overnight or after eating.

Healing Canker Sores

Canker sores can make eating, talking, and even smiling painful. Using alum powder is an age-old remedy that may accelerate healing.

With clean hands, simply touch a small pinch of alum directly to the canker sore. Yes, this will sting quite a bit for a minute. But do it 3-4 times a day and most sores disappear within 48 hours.

You can also make an oral rinse with salt and alum to treat canker sores indirectly. This reduces the intensity of the stinging sensation.

Strengthening Gums

Bleeding gums are not only painful while brushing and flossing, they allow more bacteria into your bloodstream. This raises risks for inflammation and heart disease.

Use alum powder to strengthen delicate gums and prevent further bleeding. Combine powdered alum with salt, black pepper, and/or cinnamon. Massage this paste into swollen, tender gums with a soft brush or your clean finger.

Do this daily after regular brushing and flossing. Within days to weeks, your gums will toughen up and bleed less during oral hygiene sessions.

Water Purification Uses

In addition to personal uses for health and hygiene, alum powder has applications for community water treatment. The minerals act as a chemical "flocculant" that removes impurities.

Removing Suspended Particles

One problem with untreated surface water from lakes, rivers, and reservoirs is turbidity. This refers to mud, silt, algae, and other particles suspended throughout the water.

As a flocculant, alum causes these particles to aggregate and drop out of the water more rapidly. The alum solution neutralizes the electrical charges keeping fine clay, pathogens, and organic matter afloat.

When clumped together into larger molecules called "flocs", these impurities become heavy enough to sink to the bottom by gravity. This lets clean water filter through or be skimmed off the top more easily.

Municipal water authorities frequently use aluminum sulfate or other alum solutions to clarify drinking water for public consumption and distribution.

Disinfecting Hazardous Microbes

In addition to clearing up aesthetic impurities, alum flocculation removes potentially hazardous microorganisms from water. Algae, bacteria, viruses, fungi, and parasites become trapped in the chemical flocs alongside clay and silt particles.

Adding a form of alum powder as one step in multi-barrier water processing effectively reduces concentrations of E. coli, Giardia, Cryptosporidium, and other disease-causing microbes. This helps ensure safer drinking water.

So while you may not be purifying water at home, alum powder contributes to your household's supply of clean, potable water.


How do you use alum powder on the skin?

To use alum powder as part of your skincare routine, mix equal parts powder and rose water. Apply this paste to your clean face, leave it on for 5-10 minutes, then rinse. Using this face mask 2-3 times a week exfoliates dead cells, shrinks pores, and tightens skin.

What does alum powder taste like?

Alum powder has an astringent, sweet flavor. Some compare it to the taste of acidic mineral water. It leaves a dry, puckering mouthfeel similar to strong brewed black tea.

Is alum powder safe to consume?

In small quantities, alum powder is safe for human consumption. But ingesting more than one ounce may be toxic. Limit intake to about 1/4-1/2 teaspoon per recipe when cooking or canning. Avoid swallowing oral health rinses containing alum.

Can you use alum powder every day on your underarms?

It's best not to use alum as a daily deodorant. Too much alum may irritate sensitive underarm skin. Instead, use a natural alum block or alum powder paste every other day. The mineral salts will continue absorbing odor between applications.

What toothpastes contain alum powder?

Some natural or ayurvedic tooth powders include alum powder for its ability to kill germs that cause bad breath and gum disease. But most commercial toothpastes don't list alum in their ingredients. Make your own antibacterial paste by combining alum powder with mint, cinnamon, salt, baking soda, and coconut oil.


From the spice cabinet to the medicine cabinet and beyond, alum powder is handy to have around the house.

The same jar of potassium alum works wonders in a variety of ways, from keeping pickles crunchy and fruit fresh to clearing up skin, whitening teeth, and even clarifying drinking water.

Keep this mineral salt on hand to replace several single-use products with one versatile powder.

Sarah Cortez
Sarah Cortez

My name is Sarah and I'm a baker who loves trying out new recipes and flavor combinations. I decided to challenge myself to use a new spice or ingredient powder in my baking each week for a year. Some successes were the cardamom sugar cookies, vivid turmeric cake, and beetroot chocolate cupcakes. Failures included the bitter neem brownies and overwhelmingly hot ghost pepper snickerdoodles. Through this experience I've discovered amazing additions to spice up desserts while learning how to balance strong flavors. Follow my journey as I push the boundaries of baking with unique powders!

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