Japan’s Matcha Faces Heat Stress

Warmer nights and unstable spring temperatures are putting pressure on Japan’s matcha production, especially by altering the balance of amino acids and bitter compounds that shape flavor.

Evidence indicates that heat can reduce quality and may affect tencha yields, although national production has continued to rise and recent records do not establish a clear decline caused by warming. Japanese breeders and growers are responding with genomic selection, adjusted harvest timing, and possible geographic diversification, while researchers caution that genetic screening still needs conventional field trials.