There’s something deeply satisfying about sipping a cold beer from a perfectly clean glass. Yet, over time, beer mugs can accumulate stubborn grease and residue that regular dish soap struggles to remove. One age-old trick, often passed down through generations of bartenders and homebrew enthusiasts, involves using salt as a natural scrubbing agent. This method isn’t just effective—it’s also surprisingly simple and eco-friendly.

The science behind salt’s cleaning power lies in its abrasive texture. Unlike harsh chemical cleaners, coarse salt granules provide just enough grit to lift away oily films without scratching delicate glassware. When combined with a small amount of water or vinegar, salt transforms into a potent paste that breaks down grease molecules clinging to the interior of beer steins. This makes it particularly useful for removing the lingering haze caused by hop oils or dairy-based beverages like stouts and porters.

To try this method, start by rinsing the mug with warm water to loosen any surface debris. Then, sprinkle a tablespoon of coarse sea salt or kosher salt into the glass. The larger crystals work best for scrubbing. Add just enough water to create a gritty slurry—about a teaspoon should suffice. Using your fingers or a soft cloth, vigorously rub the mixture along the interior, paying extra attention to the bottom and sides where residue tends to build up. The salt will gradually turn cloudy as it absorbs oils, a clear sign it’s doing its job.

For particularly stubborn stains, some brewers swear by adding a splash of white vinegar to the salt paste. The acetic acid in vinegar acts as a natural degreaser, enhancing the salt’s abrasive action while neutralizing odors. After scrubbing, rinse the mug thoroughly with hot water. Hold it up to the light—you should notice an immediate difference in clarity. If any haze remains, repeat the process before drying with a lint-free towel to prevent water spots.

Beyond its practicality, this technique has historical roots. Before modern detergents, taverns often relied on salt and sand to scour drinking vessels. Sailors would use seawater and sand to clean their tankards during long voyages. Today’s craft beer culture has revived these traditional methods, partly out of necessity (some delicate glassware shouldn’t go in dishwashers) and partly for the ritualistic satisfaction of hand-cleaning specialty mugs.

Environmental benefits add to the appeal. Salt is a renewable resource that doesn’t contribute to chemical runoff like synthetic cleaners. It’s also inexpensive and universally available—no need for specialty products. For those who frequent farmers’ markets or zero-waste stores, bulk salt makes this approach even more sustainable. Plus, unlike plastic scrubbers that shed microfibers, salt dissolves completely, leaving no physical waste behind.

Of course, not all glassware requires such intensive cleaning. For everyday rinses, a quick wash with mild soap suffices. But for cherished beer glasses—especially those used for aromatic IPAs or creamy nitro brews—the salt treatment can restore them to like-new condition. Some collectors even incorporate it into their glass maintenance routine monthly to prevent buildup. Just avoid using this method on pewter or metal-lined mugs, as prolonged exposure to salt can corrode certain materials.

Next time your beer glass loses its sparkle, skip the harsh chemicals and reach for the salt shaker instead. This humble pantry staple might just become your secret weapon for spotless glassware—proving once again that sometimes, the simplest solutions are the most effective.