Forming Emulsions

Appears in
On Food and Cooking

By Harold McGee

Published 2004

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Emulsions have always been considered fickle concoctions, by chemists as well as cooks. One chemist wrote in 1921 that contemporary books on pharmacy were “filled with elaborate details as to the making of emulsions,” and recorded two such details: “If one starts stirring to the right, one must continue stirring to the right, or no emulsion will be formed. Some books go so far as to say that a left-handed man cannot make an emulsion, but that seems a little absurd.” The worry is always that at some point the emulsion may break and separate into blobs of oil and water again. This can happen, but it’s almost always because the cook has made one of three mistakes: he has added the liquid to be dispersed too quickly to the continuous liquid, or added too much of the dispersed liquid, or allowed the sauce to get either too hot or too cold.