Butter Ganache

Butter ganache is a relatively low-moisture center that contributes water only minimally to moisture migration. Not only does butter ganache have a low water-activity level (A_w), it is a water-in-fat emulsion, so the water it does contain is locked in a matrix of fat, preventing migration. The fat in butter ganache is not as prone to fat migration as are the oils in nuts, and therefore it does not as a rule adversely affect other fat-based centers or chocolate. Butter ganache cannot tolerate high heat and must be deposited only after layers that are deposited hot have cooled.