Liquid Castile vs. Bar Castile – What’s the Difference?

We’ll go ahead and state this upfront: for all body applications, from washing hair, face, body, or shaving, Dr. Bronner’s Castile Soap Bar and the Liquid Castile are interchangeable. That said, our liquid soaps carry a slightly stronger scent, and the bar soaps are a bit more moisturizing. In this guide, we’ll break down each difference so you can choose the right soap for you and all your cleaning needs!

Table of Contents

      The Benefits of Castile Soap Bars Over Liquid

      castile bar soaps


      While there’s quite a bit of overlap in its many uses, our bar soaps actually have liquid beat in a few areas:

      More Environmentally Friendly
      Reducing plastic packaging is a fundamental to our All-One Mission. Our liquid soap bottles use 100% post-consumer recycled plastic (PCR) and are recyclable, but the bar soap goes a step further by utilizing a 100% PCR wrapper, completely avoiding plastic. (To cut down even further on our plastic usage, we recently launched a Carton Refill for our liquid soaps!

      More Compact
      Because our bars have less water content and are more compact, they save quite a bit of space and weight, ultimately providing better value.

      More Shower Friendly
      Unlike liquid soap, the bar soap won't slip through your fingers in the shower and is easier to control, making it ideal for kids and keeping soap away from a baby's face.

      More Travel Friendly
      Bar soaps offer spill-proof convenience unlike their liquid counterparts. They remain intact even in hot conditions, making them ideal for travel without the TSA compliance worries associated with carrying more than 3.4 oz. of liquid.

      More Moisturizing
      Our bar soaps offer a slight boost in moisturizing properties compared to the liquid form (more on that below).

      Be sure to check out our Bar Soap Dilutions Cheat Sheet for a more comprehensive breakdown of its potential uses!

      Ingredient & Formulation Differences in Our Bar & Liquid Soaps

      liquid castile and bar soap castile differences

      Side-by-side of our Baby Unscented Soap, which doesn't contain any essential oils.

      Choosing to go with either the liquid or bar soap really comes down to a matter of personal preference. With that in mind, there are a few ingredients and formulation differences in their composition.

      Dr. Bronner’s Liquid Soaps:

      • Contain more water in order to maintain their liquid form. If they contained less water, they’d start to solidify over time.
      • Use potassium hydroxide to saponify the oils. This alkali separates the glycerin from the fatty acids. (Read more about the saponification process).
      • Contains palm kernel oil which also has lauric acid.
      • Use hemp seed and jojoba oils that are saponified (turned into soap) at the same time as the other oils. If they were added after, the hemp and jojoba would separate and float to the top.
      • Have a higher amount of essential oils than the bars (doesn’t apply to our Baby Unscented Soaps). These essential oils in a high concentration cause the soap to soften, so our bars are limited in how much they can contain in comparison to the liquid. Because of this, the liquid soaps tend to have a stronger scent than the bars.

      Dr. Bronner’s Bar Soaps:

      • Use sodium hydroxide which produces a harder soap than the potassium hydroxide found in the liquid soap.
      • Contain palm oil as opposed to palm kernel oil. Saponified palm oil solidifies into a harder soap, and it contains stearic acid, which many people find to be less drying than lauric acid. For this reason, the bar soaps tend to be more moisturizing than the liquid soaps.
      • Contain sodium chloride, or table salt. This serves as a hardener and also makes the bars a bit more moisturizing than their liquid counterpart as salt water tends to be gentler on skin than pure water.
      • Use hemp seed and jojoba oils that are added after the saponification process. This also aids in the bars being more moisturizing.
      • Have lower amount of essential oils compared to the liquid soap. The bars wouldn’t retain their hardness if they contained the same percentage of essential oils as the liquid soap.

      Body & Usage Differences of the Liquid & Bar Castile Soaps

      As previously mentioned, when it comes to body care, Dr. Bronner’s Liquid and Bar Soaps are interchangeable – the slight differences being that the liquid tends to have a stronger scent and the bars tend to be more moisturizing. When it comes to cleaning more than just your body, such as home, laundry, car, etc., the bar soap needs the extra step of dissolving it in water before using it in a spray bottle, for example. For a more extensive breakdown of how to use these products for a number of cleaning tasks, we encourage you to check out these resources:

      Special thanks to Lisa Bronner of Going Green for this content!

      Peppermint - Pure-Castile Bar Soap

      Peppermint - Pure-Castile Bar Soap

      Smooth-soft lather!

      Shop soap