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An Alum Block Is the Secret Weapon You’ve Been Missing From Your Post-Shave Routine

If you’re familiar with so-called old-school shaving, then you already know how great an alum block can be as an aftershave. But if you’re new to the history of shaving, let us introduce you to the original aftershave.

What is an alum block?

When you see alum, that’s typically referring to potassium alum, a chemical compound with antibacterial and astringent qualities. So an alum block is just a small brick of potassium alum, typically 2 to 5 ounces, that you can use to shrink blood vessels, reduce inflammation and redness and stop bleeding from small nicks and cuts after shaving. As a bonus, because of these features, alum blocks are also popular as natural deodorants and have even been used to lock in styles on wet hair.

How do I use an alum block?

  • Once you’re finished shaving, give your face a cold rinse. This washes off any residue from shaving cream, remaining hairs and starts to close your pores.
  • Now, grab the alum block, hit it with some cold water too and start gently running it over the places you just shaved, especially nicks and cuts. It seems simple but the alum block is already working its magic to soothe your skin and close up cuts. As a part of this, you may feel a little stinging and burning. That’s normal and a roadmap for the spots to go easier on next time. Once you’ve done a decent once or twice over, stop.
  • Let your face sit for 15-20 seconds and then rinse. Some instead prefer to leave the alum on without rinsing at the end.
  • Make sure to dry or at least shake off any excess water on the alum block before storing it.
  • Ultimately, no matter how you do it, it won’t really affect how the alum block performs, so we recommend doing what works for you and leaves your skin feeling the best.

Once you’re finished applying an alum block, the only thing left to do is celebrate having cleaner, less inflamed skin. If you use an alum block consistently, you’ll see results and wonder why you never gave it a shot before, especially when it’s so cheap compared to pricey, if also great, aftershave balms and creams. Even better, alum blocks can easily be used in conjunction with the best aftershave balms and facial moisturizers too for the absolute best post-shave results.

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To get you started, we rounded up a few great alum block options below. This is the rare product where there truly isn’t a ton of difference between options because they will all be blocks of potassium alum. The choices really come down to the size of the alum block, the price, the inclusion of a case and just plain old brand preference. But in the end, every alum block below will improve your aftershave experience by quickly minimizing cuts, redness and irritation, even if it’s not bringing any moisturization or hydration to the table.


1. Taylor of Old Bond Street Alum Block


For the best overall alum block, we’re fans of the Taylor of Old Bond Street Alum Block.

It’s a smallish brick around 2.6 ounces, easily held and maneuvered and is, as promised, 100% potassium alum. Though it’s on the smaller side, it’s dense and will still last you through many, many shaves.

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Courtesy of Amazon


2. GBS Alum Block 3 Stone Pack


If you want the best bang for your buck, you want the GBS Alum Block 3 Stone Pack. You get three 2.8 ounce alum blocks as well as a plastic case. That’s far and away the best price per ounce of alum we found by a long shot. But they’re quality blocks too and won’t easily disintegrate, so you’ll have an alum block for years to come.

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Courtesy of Amazon


3. BarberUpp Alum Block


We’re splitting hairs over a few bucks, but if you want to spend as little as possible — say for a cheap test run you won’t feel bad about throwing away — the BarberUpp Alum Block is among the cheapest alum blocks available. Even though the alum block is cheap, BarberUpp didn’t skimp on size. At 3.5 ounces, this block will give you months of relief. Plus, a case is included, which is always helpful and nice at this price point.

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Courtesy of Amazon


4. Gentleman Jon Alum Block


The Gentleman Jon Alum Block is one of the most popular and best-reviewed alum blocks on Amazon for a few good reasons. The block is hefty enough to last at 3.7 ounces, breaks down appropriately slowly, comes with a decent plastic case and does what potassium alum is supposed to do. It does all this at a very reasonable price too. What’s not to like?

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Courtesy of Amazon


5. Parker Safety Razor Large Alum Block


If you know you love alum and just want a big block for your sink counter dish, the Parker Safety Razor Large Alum Block is the block you want. At 4.4 ounces, it was the biggest single alum block we found. It comes with a plastic case, but multiple reviewers suggested it broke easily, so this alum block is best kept in one place at home.

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Courtesy of Amazon


6. Mike the Mason Nick Brick


It’s always a good time to support a smaller producer. The Nick Brick from Mike the Mason promises to take care of your nicks. With 3.5 ounces of solid potassium alum, you’ll be able to put the Nick Brick to work shave, after shave, after shave. Not only will you be supporting a small business, based in Florida, but this business also donates 5% of its net profits to community organizations every month.

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Courtesy of Amazon


7. Gentleman Jon Complete Wet Shave Kit


To get the full old-school shave experience, alum block and all, you have to shave with a great safety razor. If you don’t know where to begin, the Gentleman Jon Complete Wet Shave Kit has everything you need: the Gentleman Jon Alum Block, a safety razor, a badger hairbrush, a shave soap, a steel bowl and five razor blades. Just don’t forget to use the alum block at the end for best results.

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Courtesy of Amazon


For the Sake of Your Skin (and Your Sanity), Use an Aftershave Balm After Shaving