What it is
E481 (sodium stearoyl lactylate, SSL) is made by reacting lactic acid with stearic acid. The lactic acid is microbially fermented and vegan; the stearic acid component can come from plant fats (palm, coconut) or animal fats (tallow).
Why it matters
Used as a dough strengthener and emulsifier in commercial bread, biscuits, cake mixes, and packaged baked goods. Often paired with E471 / E472 in the same product.
What to do
Variable, exactly as with E471. Most UK supermarket bread now uses plant-derived stearic acid, but always ask if you cannot tell from the label. The closely-related E482 (calcium stearoyl lactylate) has the same considerations.