Supermild Castile has outstanding water softening and cleansing powers, preferable to harsh soap & defattening synthetics. It does not cut dirt, but dissolves it. It is the mildest, most pleasant soap you have ever used.

Soap is made by saponifying a fat or oil with a strong alkali. A fat or oil is a triglyceride, which means that three fatty acids of various carbon lengths are attached to a glycerine backbone. The strong alkali is either sodium (for bars) or potassium (for liquids) hydroxide. The saponification process is a simple one-step reaction with no waste generated: the glycerine is split off from the fatty acids, and the fatty acids combine with the sodium or potassium to form soap, while the hydroxide forms water. The result is soap, glycerin and water (no alkali remains).

Quality soap-making consists in great part in choosing the right proportions of the right oils with their different fatty acids. Most commercial soaps skimp on quality because of cost, and use lots of tallow from beef fat with a little bit of coconut or palm kernel oil. Our unsurpassed soaps use olive, hemp, and palm oils instead of tallow, and use three to four times more coconut oil than commercial soaps. Saponified coconut oil generates high-lather cleansing even in hard water because it has shorter-chain saturated fatty acids. Hemp, olive, and palm based soaps make a mild, smooth, creamy lather, because these oils contain longer chain unsaturated and polyunsaturated fatty acids.

Dr. Bronner's makes a higher quality soap in other ways as well. Unlike most commercial soapmakers who distill the glycerin out of their soaps to sell, we retain it in our soap for its superb moisturizing qualities. We also superfat our soap with olive fatty acid, which both ensures that there is no free alkali, and lowers the pH, making a milder, smoother lather. We use rosemary extract and plant-derived vitamin antioxidants to protect freshness (the rosemary is effective at 0.005%, so it contributes absolutely no scent). We do not add any chelating agents, dyes, whiteners, or synthetic fragrances.

We use only 100% pure high quality essential oils. Our liquid soaps are so concentrated that they are only a few percent away from being a solid, which ecologically saves on packaging materials. They are a superb value, costing less than less-concentrated inferior detergent body-wash "liquid soaps." Our soaps are most popular for at-home washing, but they also are the choice when camping and hiking, as our soaps are so biodegradable and nature-friendly. Dr. Bronner's soaps have spread by quality and word of mouth alone into virtually every health food store in the country. Unsolicited articles raving about our soaps have appeared in magazines and newspapers as diverse as Natural Health, Outdoor Gear, Vogue, The Washington Post, The Chicago Tribune, The Associated Press, The Wall Street Journal, Parenting and New Age.