Cheese-making instruction. 素早く ('quickly, swiftly') is an i-adjective form of 速い + a prefix 素. 静置する ('to let stand, to leave undisturbed') is a technical term for letting something sit without stirring — used in chemistry, cooking, and lab procedures. 固まる ('to harden, to set, to curdle') is used for processes like cheese-making or gelatin setting.