To remove a water stain from leather, wipe the stained area with a sponge soaked with water, blot the surface of the leather with a dry, clean cloth and allow it to dry. Once the surface is completely dry, soften and condition the leather with saddle soap.
Before cleaning off the stain, ensure the sponge is clean and free of staining materials, such as beverages and food, which may aggravate staining. Put room-temperature water in a clean container. Immerse a sponge in the water and wring out excessive moisture prior to cleaning off the stain. Excessive water, in addition to spilled water or condensed water from a glass that has been left on the surface of the leather may evaporate and result in water marks.
Use the damp sponge to gently moisten the entire surface of the stained area. Once the surface is damp, work out the stain outwards to avoid moving the staining material to other areas or causing a new stain.
Prevent a water stain from forming by wiping it off as soon as it occurs with a clean, damp sponge. Take care not to use harsh cleaners, such as saddle soap, when cleaning, because such cleaners may bring about more stains.