A method of preparing an oil-in-water emulsion comprises combining (A) an organopolysiloxane including at least two silicon-bonded hydrolysable or hydroxyl groups and (B) an organic oil to give a mixture. The method further comprises combining the mixture, (C) an aqueous medium and (D) a surfactant to form an initial emulsion. Finally, the method comprises contacting the organopolysiloxane (A) with (D1) an organic acid catalyst to polymerize the organopolysiloxane (A) to give (A1) a high molecular weight organopolysiloxane and the oil-in-water emulsion. A personal care composition comprising the oil-in-water emulsion and a personal care ingredient is also disclosed.