Theory: Bloom Strength

Bloom strength is the measurement that is used to describe how firm a gel will be formed by a standard quantity of gelatin dissolved in a standard quantity of water. The term “Bloom” pays respect to the American scientist Oscar T. Bloom, who in 1925 patented a machine called a Bloom Gelometer that measures the strength of gelatin gels. Modern variations of this original machine are still in use today. Typical Bloom ratings run from 50 to 300 Bloom; the higher the Bloom rating, the firmer the gel will be that is formed. Higher Bloom gelatins not only require a smaller amount of gelatin in the formulation, they typically have a shorter texture, higher melting points, more neutral odor and flavor, and gel more quickly than lower Bloom gelatins, and so are desirable for most confectionery applications. The commonly available granulated gelatin in America is 250 Bloom, and is the standard used for gelatin in all formulas in this book.