Why would a brewer choose to use cold steeping for certain grains?

Cold steeping is a method employed by brewers primarily to reduce the astringency associated with roasted grains. When grains are steeped in cold water, the extraction of certain compounds that contribute to astringency, such as tannins, is minimized. Cold steeping allows for the flavors, colors, and desired characteristics of roasted grains to be incorporated into the brew without the harsher, bitter notes that can arise from hot steeping or full mashing.

This technique is particularly advantageous when adding dark grains to a beer recipe, as it enables the brewer to achieve the desired color and flavor profile while maintaining a smoother mouthfeel in the final product. The result is a beer that showcases the rich characteristics of the roasted grains without the negative impact of excessive astringency.