fold in

US /foʊld ɪn/
UK /foʊld ɪn/
"fold in" picture
1.

混ぜ込む, そっと加える

to gently mix an ingredient into a mixture, especially a delicate one like whipped cream or beaten egg whites, without losing air or volume

:
Carefully fold in the egg whites to the batter.
卵白を生地にそっと混ぜ込む
Once the chocolate is melted, fold in the whipped cream.
チョコレートが溶けたら、ホイップクリームを混ぜ込む