Q. After making homemade bath bar soap (consisting of tallow, coconut oil, palm oil, and lye), upon removal from the forms, we placed the soap blocks on wax paper and set it on our quartz counter tops. After being gone for a few days, we returned to find that the soap had created white stains on our gray quartz. Is there a solution that might work to pull that white stain out? A specific poultice concoction or product? I'm told that the lye would have been "inactive" at that point, but I suspect it is the culprit. Or maybe something in the wax paper is? Thank you in advance for you help.
A. A true stain is always darker than the stained material. Since you describe the discoloration as "white," we can assume that these are not stains that can be cleaned off of or pulled out of the quartz. What you're dealing with is likely alkaline surface damage from residual active lye in your soap.
Here’s what you can do. First, try a gentle cleaning to remove any residue on the surface. Use warm water and a mild dish soap for this. Rinse and dry with a soft microfiber cloth. Although these steps won’t reverse the bleaching, they will stop further alkaline residue from reacting.
Utilizing the services of a professional stone restoration contractor specializing in quartz is the safest solution. They can assess whether the quartz can be lightly honed or polished to remove the alkaline etching without damaging the surrounding surface. To find a vetted PRO in your area, visit www.surfacecarepros.com and click on Find a PRO.
In the future, use a reliable non-reactive barrier like parchment paper, a tray, or a cutting board, and wipe any soap residue immediately to prevent damage.
ABOUT THE AUTHOR Fred Hueston is the Chief Technical Director at SurfaceCarePROS.com and Director at StoneForensics.com. He is also the author of Stone and Tile Restoration: The Manual, a comprehensive online manual for stone and tile restoration contractors. [Learn more about Fred.]
Article ID: 850
Created: January 9, 2026
Last Updated: January 11, 2026
Author: Fred Hueston
Online URL: https://surfacecarepros.com/kb/article/how-to-remove-white-marks-quartz-from-homemade-soap-850.html