For many of us, doing the dishes is a daily ritual. But the product we use—whether squeezed from a plastic bottle or rubbed off a solid bar—can make a surprising difference to our skin, our home, and the planet.
Dishwashing soap bars are one of those small switches that can quietly transform your routine. If you're curious about what’s actually inside them, how they work, and why so many eco-conscious households are embracing them, this guide is for you.
What is a dishwashing soap bar?
At its core, a dish soap bar is simply a concentrated block of solid soap formulated to cut through grease and grime. Unlike typical dishwashing liquid, which is mostly water packaged in plastic, these bars are waterless and packaging-free (or close to it).
You use them just like bar soap—only instead of lathering onto your hands or body, you’re loading up your dish brush, cloth, or sponge.
What are they made from?
Most dish soap bars are made from plant-based oils (like coconut or olive), water, and lye (sodium hydroxide)—which transforms the oils into soap via saponification. That’s the traditional method of soap-making, and it’s remarkably effective.
At Biome, we only stock bars that are free from palm oil and petrochemical derivatives. This matters because palm oil production—particularly in South East Asia—continues to drive deforestation, habitat loss, and human rights abuses.
Why do dish soap bars matter for the planet?
Here’s where the real impact lies. A dish soap bar:
- Eliminates the need for plastic bottles
- Reduces transport emissions (they’re lighter and more compact)
- Usually fully biodegradable
- Supports a zero waste kitchen setup
And unlike traditional detergents, they don’t release synthetic surfactants or questionable preservatives down the drain.
How do you use a dish soap bar?
It’s beautifully simple.
- Wet your soft bristle dishcloth, sponge or brush.
- Swirl it gently on the soap bar until it lathers.
- Use those suds on the cloth or brush directly on to wash your dishes.
- Repeat as needed. You’ll notice that while the lather may be less bubbly than liquid soap, it’s no less effective. In fact, it cuts through oily residues impressively well.
- Lastly, rinse off the residue.
Using a soft bristle brush is important. Hard bristles will just scratch the bar and not lather properly.
Find our favourite dish cloths and sponges
Are dish soap bars as effective as liquid soap?
Yes—and in many cases, even more so. Because you control the amount used (no squirting out half a bottle by accident), a bar can last significantly longer.
They're especially good at tackling grease thanks to their high soap content and the naturally degreasing properties of ingredients like coconut oil and lemon essential oil.
Are there different types?
Yes—though not all dish soap bars are created equal.
If you’re looking for a direct comparison, head over to our real-world review post, What Makes the Best Dish Soap Bar?, where we test and compare them side by side.
Where should I store my dish soap bar?
To keep your bar solid and long-lasting:
- Let it dry between uses.
- Store it on a well-draining soap dish or soap rack (not sitting in water).
- Keep it away from direct water spray.
A dry bar is a happy bar—and will last much longer.
What else can you clean with a dish soap bar?
Surprisingly, quite a lot. Beyond your plates and cutlery, a dish soap bar can be used to clean:
- Kitchen benches
- Stainless steel cookware
- Reusable coffee cups and lunch boxes
- Cloth pads and reusable nappies (pre-wash)
- Your hands after gardening or cooking
Some people even take a small one camping or travelling—compact, leak-proof, and multipurpose.
Explore our favourite palm oil free dish soap bars
Urthly Organics Dish Soap Bar – Naturally scented with eucalyptus and lemongrass, with added bicarb for extra power.
Shop all dish soap bars here
FAQ: common questions about using a dishwashing soap bar
Can you use a dish soap bar in a dishwasher?
No, dish soap bars are for hand washing only. They create suds that can overflow in a dishwasher and potentially damage the machine. For dishwashers, use a low-tox, biodegradable detergent specifically made for that purpose.
Is a dish soap bar safe for septic systems?
Yes—most natural soap bars, including those sold at Biome, are greywater safe and suitable for septic tanks. They’re free from synthetic antibacterials or harsh surfactants that could harm the bacteria balance in your system.
Will a dish soap bar dry out my hands?
Many people find natural dish soap bars gentler than conventional detergents, especially those made with nourishing oils like coconut or olive. But if you have very dry or sensitive skin, wearing gloves may still help—particularly in colder months.
Can dish soap bars remove burnt or stuck-on food?
They can, especially when paired with a good scrubber. For extra power, sprinkle a bit of bicarb soda directly onto the surface and then use your soap-lathered sponge or brush to lift the residue.
Do dish soap bars expire?
They don’t go “off,” but they can dry out or lose fragrance over time. Keep unopened bars in a cool, dry spot and store opened ones on a draining rack to prolong their life.
Can I cut my dish soap bar into smaller pieces?
Yes! Cutting the bar into halves or quarters can make it easier to use or take on the go (like for camping). Just use a clean kitchen knife and store unused pieces in a dry container.
Is a dish soap bar cheaper than washing up liquid?
While dish soap bars may have a slightly higher upfront cost than their liquid counterparts, they often last longer, making them a cost-effective choice in the long run.
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