Any soap that is an effective cleanser and washes clean (i.e. doesn’t leave any kind of residue) is suitable for preparation for mikveh.

Common custom is not to be particular about the soap used for mikveh preparations, and just wash off visible residue, as is ordinarily done when bathing or showering. Suspected, but not clearly seen or identifiable soap residue is not usually cause to invalidate immersion. Soaps with moisturizer are generally not problematic, since moisturizer is typically absorbed into the skin, not leaving a residue.

If you are especially concerned about soap residue, you may want to try a liquid soap, which can be less prone to leaving any residue.

We are not aware of what type of soaps were used in antiquity.

This response was updated on 11 November, 2025.