初级肥料 and 高级肥料只对其中一个咖啡豆有影响, leading to an average 3-7g gain per harvest. Over both seasons this adds up to 70-160g increased profit. 生长激素可以让你多收几次咖啡, 给你60g increased profits.
In order to make 咖啡, 5 Coffee Beans from one stack must be put into the 小桶. It is not possible, for example, to place 3 Coffee Beans of silver quality and 2 of gold quality into a Keg, because the different quality levels are not stackable with each other, and the Keg will only accept 5 Coffee Beans at a time.