The removal of fat from something, either physically or chemically(noun)
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Use "defatting" in a sentence
"Instead of cooling and defatting the broth after the meat step, you would just poach the chicken in it directly after separating all your stuff, and then refrigerate all."
"I am particularly attached to the ladles with pour spouts, which are great for defatting and descumming soups and directing the flow of scalding jam .."