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If you’re familiar with shaving culture and its many accessories and tools, you may have already heard of an alum block.

An alum block is a mineral block, made of potassium alum, that has a long history of use as a post-shaving tool. It can be used on the skin after shaving to stop bleeding, reduce inflammation, and more.

Let’s explore what an alum block is, how it benefits the skin after shaving, and how to use it.

An alum block is a mineral block made of potassium alum, a compound that has antiseptic and astringent properties. The antiseptic properties of the alum block offer protection against disease-causing microorganisms, while the astringent properties help reduce inflammation and bleeding.

Generally, an alum block is used after shaving to soothe the skin, prevent the spread of bacteria, and reduce bleeding associated with minor nicks and cuts. It can also be used to prevent some of the more annoying side effects of shaving, such as razor burn and ingrown hairs.

Alum block vs. styptic pencil

Both alum blocks and styptic pencils are made from alum, a compound that has many uses outside of shaving. The astringent properties of alum blocks and styptic pencils help soothe the skin after shaving.

However, while both products can be useful in your shaving routine, there are some differences in what they can do.

  • Alum blocks are usually reserved for minor cuts and nicks that may happen during shaving. They can also be used as a natural deodorant, or as a part of a skin care routine to reduce acne. The mineral block form has a longer shelf life.
  • Styptic pencils are a more traditional piece of post-shaving equipment reserved for more serious cuts. Styptic pencils aren’t just used for shaving. They also work against most types of minor bleeding. The powder pencil form may be used up more quickly than an alum block.

Even if you’ve never heard of an alum block before, using one is surprisingly simple.

  1. After you’ve completed your shave, rinse the area with cold water. Make sure no soap or shaving cream remains on the skin.
  2. Wet your alum block with cold water. This is an important step. Some people even choose to soak their alum block in cold water before using it.
  3. Run the wet alum block gently over the skin. You may feel a tingling, stinging, or burning sensation, especially if you have cuts or razor burn from a dull blade.
  4. Allow the alum residue to sit on your skin for 15 to 20 seconds. This allows the crystals to tighten the pores and cleanse the skin.
  5. After 15 to 20 seconds, rinse the residue off with cold water.
  6. Apply moisturizing cream or aftershave.

After using the alum block, pat the block down fully with a dry towel before you store it. If you’ve soaked your block before using it, consider leaving it out on a safe surface to dry completely before the next use.

Some amount of tingling, stinging, or even burning is normal when using an alum block after shaving. This happens because of the antiseptic and astringent properties of the crystals in the alum block.

Rarely, using an alum block may cause skin irritation that doesn’t go away when the residue is rinsed off. If you notice excess irritation or believe that you’re allergic to alum, you should speak with a doctor before using an alum block again.

While alum blocks are commonly used as an aftershave accompaniment, they also have a handful of uses outside of shaving.

Alum block after waxing

Waxing eliminates nicks and cuts commonly associated with shaving and reduces the risk of ingrown hairs. However, skin can still become irritated after waxing, especially if the wax was too hot or the process was too rough.

This makes the antiseptic and astringent properties of alum beneficial for freshly waxed skin as well.

Alum block as a deodorant

Deodorant and antiperspirant products work by eliminating bacteria and reducing perspiration. There are various types of natural deodorants, including a type of crystal deodorant made of potassium alum.

Alum block deodorant is a great natural alternative that can help kill bacteria and keep your armpits feeling and smelling fresh.

Alum block for acne and dark spots

Acne treatments rely on compounds like salicylic acid to help reduce acne by exfoliating, cleaning, and tightening the skin. As it turns out, alum can also help clean out bacteria and tighten pores, which may reduce acne lesions.

Proper storage plays an important role in the lifespan of your alum block. Once an alum block is exposed to water or moisture, the crystals begin to dissolve. While this is great for immediate use, it’s not so great for long-term storage.

It’s important to dry the alum block completely before storing it. Store the alum block in a cool, dry place with access to adequate airflow. This helps evaporate excess moisture between uses to keep your block dry.

Stores that sell professional shaving equipment and kits should also sell alum blocks. They may be located with the shaving equipment or included with aftershave products. Alum blocks come in various sizes, so you’ll want to choose the best size for you based on how often you plan to shave.

Shop for an alum block online.

Alum blocks are crystallized blocks of potassium alum, an antiseptic, astringent compound.

An alum block can be used to help eliminate some unwanted side effects of shaving, such as minor bleeding, skin inflammation, and even razor bumps. Alum blocks can also be used as a deodorant or as a part of a skin care routine for acne.