How many purpose metal screens do you use to make coffee by hand? What is the difference between a metal filter and a filter paper? How many microns is 400 mesh equal to?

Because the comprehensive performance of filter paper is excellent, it has become the mainstream filter material for hand-brewed coffee. But filter paper is not the only filter material. In addition to filter paper, there are also filter tools made of flannel, metal and other materials. Different materials have different characteristics and characteristics. If we want to use filter tools of different materials to make a cup of coffee, we need to first master their characteristics and characteristics. Because flannel filter cloth has been shared a lot, Qianjie came to share today on how to use a metal filter to make a cup of coffee~

Advantages and Disadvantages of Metal Filters The metal filter held by Qianjie is a random purchase online. The filter has a diameter of 400 meshes and looks like an inverted cone with a flat bottom. The filter itself is divided into two layers: inner and outer. The inner layer is a 400-mesh filtering metal mesh, and the outer layer simply plays a fixing role.

The corresponding particle size of 400 meshes is 38 microns, which can be said to be a very small pore size, so even if the coffee powder is shaken after pouring, it will rarely fall out through the filter. This aperture is still a little larger than the aperture of the filter paper. Therefore, one of its advantages has to be mentioned here. It can retain the lipids of coffee just like flannel, which is a big improvement for coffee. Because coffee lipids are wrapped with certain oil-soluble aroma substances, their presence will add a certain aroma to coffee. At the same time, lipids can also increase the taste and give the coffee a higher mellow degree. This is an advantage that filter paper does not have. Because the filtering performance of the filter paper is too strong, it will be filtered together with the oil.

In addition, the metal filter also has the advantage of being environmentally friendly and saving money because it can be reused. Like flannel filter cloth, it only needs to be rinsed and dried after use, and then it can be put into use again. Based on the amount of one cup a day, the purchase cost of the filter can be recovered in about 100 days, which can be said to be very cost-effective. Then after talking about the advantages, let's talk about the disadvantages! The shortcomings and advantages of metal filters are the same, which come from its filter holes. Although the metal filter can release oil to enhance the aroma and taste of coffee, it can also release coffee powder. Because coffee particle sizes smaller than 38 microns are everywhere, they can easily pass through the filter, affecting the texture and taste of the coffee.

If the grinding quality of the bean grinder you use is not as high and you plan to use a metal filter for making coffee, it is best to use a sifter to sift out some of the fine powder before brewing. Otherwise, the negative impact of excessive fine powder cannot be underestimated. That's about it, then we'll use a metal filter to make coffee from Qianjie, and then share what we need to pay attention to during use~

Before brewing begins, a note should be inserted in the front street: the water discharge speed of the metal filter will increase as the water level increases. What does it mean? That is, the higher the water level you inject, the faster it will be launched. Qianjie passed tests and found that the metal filter will be launched much faster than the V60 when the water level is high. Excessive water discharge speed will reduce the contact time between water and coffee powder, which may lead to insufficient extraction. Therefore, when brewing, we need to pay attention to reducing the water injection rate to prevent the powder bed and water level from being raised too high, resulting in too fast drainage, which in turn creates the risk of insufficient extraction such as thin taste and bland taste.

The beans used in the street before this brewing were Yejia Shefei's washed bean-fruit tintin. The extraction parameters were the same as those used when using filter paper: powder amount used: 15 g Grinding degree: 10-scale grinding of Ek43, 80% sieving rate of No. 20 sieve, powder to water ratio of approximately the size of fine sugar: 1:15 (15 g of flour with 225 ml of hot water) Brewing water temperature: 92 ° C Water injection method: The first step in the three-stage stage is still steaming. We first use twice the amount of water to steam for 30 seconds.

After the steaming is over, we inject a second section of hot water (circling in a large circle), totaling 120 ml. Because the water level must be prevented from being raised too high, a small water flow must be injected at this time. At the same time, pay attention when winding the loop to avoid the water column washing the edge of the filter screen, otherwise bypass water will be generated.

When the coffee liquid completely penetrated, we also injected the third section of hot water with a small water stream, totaling 75 ml. Since the extraction center of hot water in this section is the bottom coffee powder, we need to reduce the circle and focus on extracting the bottom coffee powder at the center.

When the coffee liquor has penetrated completely, we can remove the filter cup and end the extraction! The total time was 2 minutes and 05 seconds, which was about 10 seconds faster than the time when boiling fruit tints with filter paper. The taste performance is very good. The elegant white flower fragrance, fresh lemon, and clean green tea finish are very pure Yejia Shefei flavor. Then, in terms of taste, due to the existence of oil, this cup of fruit tintin will have a more excellent mellow feeling, and at the same time, the aftertaste will be longer, which is very good~

- END -