Soapnuts effectiveness declines after repeated laundry use

A comparative study by Stiftung Warentest examined the effectiveness of soapnuts (Sapindus mukorossi) as an eco-friendly alternative to traditional laundry detergents. While soapnuts contain saponins that provide soap-like properties when in contact with water, the study found significant limitations in long-term performance.

After just six washing cycles, white textiles washed with soapnuts or horse chestnut granules began to look duller. By the twentieth wash, the fabrics appeared noticeably greyed. In contrast, test materials washed with conventional liquid detergent remained clean even after twenty cycles. The findings suggest that while natural substances can assist in loosening dirt, they may struggle to match the complete cleaning and removal capabilities of modern synthetic detergents over repeated use.