How to adjust the thickness of the bean grinder?

The importance of coffee grinder:

Bean grinders are often directly ignored in coffee recruits! This is a really sad fact! Many novices buy coffee powder directly in the supermarket. But friends with a little common sense will know that the shelf life of coffee after roasting is very short. It is generally recommended that freshly baked beans should be drunk within 1 month! Because in a month's time, the elements in the beans that can bring you the ultimate flavor will be quickly lost. Coffee ground into powder oxidizes faster because of its larger contact area with air. Generally speaking, 15 minutes after grinding is enough to turn the original boutique coffee into waste. That's why some people or merchants always advertise that our coffee is freshly ground coffee! Although sometimes those merchants themselves do not understand why they want to grind!

Some friends here will say, as long as it is not grinding right now!? I bought a few dozen yuan of spiral bean grinder on Taobao and now I can OK it. In fact, as long as your beans are good enough and fresh enough, it must be much better than buying coffee powder directly to brew and extract! But you still waste coffee beans! A spiral bean chopper (we call it a bean chopper because this machine crushes beans by chopping rather than grinding) not only can't process coffee beans into uniform coffee powder, but also generates a lot of heat in the process of chopping. Coffee powder accelerates the oxidation process when heated. The flavor will also be taken away! In addition, under the first principle of successful extraction of boutique coffee (uniform extraction), because the coffee powder particles chopped by the chopping machine are coarse and fine, it will also lead to the failure of coffee extraction! The most direct is excessive extraction, or insufficient extraction! The coffee with insufficient extraction will be sour and astringent, and the coffee with excessive extraction will be too bitter!

If you don't understand, a simple example is fried sour and spicy shredded potatoes. If some of the shredded potatoes you cut are thick and thin, then you will find that the thick ones are still raw when you stir-fry the fine ones and put them into the pan. But if you stir-fry the coarse ones, the fine ones will be fried into mashed potatoes! So a good bean grinder is the first product for good baristas in the field of boutique coffee, rather than coffee machines or other extraction tools! This is why the price of bean grinders with excellent performance can be tens of thousands of reasons!