Bar soap or liquid soap: which is best for your skin?
The question comes up in the shower every day: is liquid soap enough, or is it time to switch to bar soap? The answer depends on what you prioritize, but once you understand the differences in formulation, pH, and environmental impact, the choice is rarely difficult.
Here, we go through the key differences so you can make an informed choice for your skin and your daily routine.
Ingredients: what’s really the difference?
Liquid soap consists largely of water, often 60–80%. It requires preservatives to keep the product stable, and the surfactants used are often stronger synthetic varieties such as SLS or SLES. High-quality bar soap, especially a pH-balanced syndet bar, is water-free and requires no preservatives. The ingredient list is shorter and easier to read.
FOAM’s beauty bars use Sodium Cocoyl Isethionate, a mild surfactant derived from coconut oil, combined with Butyrospermum Parkii Butter (organic shea butter) and Glycerin as a humectant. No preservatives, no unnecessary additives.
pH and skin health
Traditional bar soap made through saponification has a high pH, around 9–10, which can disrupt the skin’s natural barrier. A pH-balanced syndet bar, on the other hand, is formulated to match the skin’s natural pH (approx. 4.5–5.5) right away, with no adjustment period. This makes it gentle enough for daily use, even on sensitive skin.
Liquid soap varies widely in pH depending on the formula. Cheap varieties can be just as harsh on the skin as traditional bar soap, while premium products are often pH-adjusted.
Environmental impact
A 60g bar of soap typically replaces 2–3 250ml bottles of liquid soap. That means less plastic, lower shipping weight, and fewer shipments. FOAM’s beauty bars are delivered without any plastic packaging at all.
To make your soap last even longer, we recommend a stoneware soap dish with drainage or an organza soap bag that can be hung in the shower.
Comparison: bar soap vs. liquid soap
| Bar soap (syndet bar) | Liquid soap | |
|---|---|---|
| Water content | None | 60–80% |
| Preservatives | Not needed | Often necessary |
| pH balance | Can be pH-balanced | Varies |
| Longevity | Replaces 2–3 bottles | One bottle |
| Packaging | No plastic | Plastic bottle |
| Suitable for sensitive skin | Yes, with the right formula | Depends on the product |
Read more in our complete guide to bar soap, or explore what makes a face soap for sensitive skin the right choice.