First, talk about the bubbles in your coffee. This has nothing to do with the coffee you use. There are two kinds of bubbles. First, the powder is too thick or not dense, and the flow rate is too fast. Second, when the flow rate is uniform, the coffee liquid rushes directly to the bottom of the cup. Imagine that we use a bucket to receive water. The faucet is far away from the bucket and the water rushes directly to the bottom of the bucket. If you catch water along the barrel wall, the water will flow down, and you will also let the coffee flow down. In addition, it is not surprising that bubbles appear when the milk foam is too thick. There is not much theory about beating milk bubbles. It's important to know how to fight and then find the feeling. When you see it, every bartender will make milk bubbles in different ways. Practice more when you find the feeling. Don't be afraid to waste costs. If you are afraid of wasting, you can practice with ice water and detergent. Don't pursue thick milk foam, but it must be delicate and have a mirror-like feeling. This kind of milk foam is the best. Pay attention to the technique, symmetry and moderate flow when washing. At this time, it doesn't matter if there are bubbles coming out. Continue flushing, and carefully flush the bubbles with milk along the cup wall. At this time, it is almost possible to pull flowers, and this step needs to be touched. Come on, practice slowly, or join me to communicate.