Coffee beans are roasted in several stages.

Beiyi style baking

In the case of relatively shallow baking (popular around Milan), this formula produces a cup of espresso that tastes like sugar water. Personally, I think this kind of formula is the best combination of sweetness and baked drupe flavor, but it is the most likely to cause problems in the extraction stage. The Beiyi formula has the greatest potential to produce sweet espresso, but it is very easy to screw up during extraction, thick and sweet dry aroma, which means that the flavor is the most complex and fragile, and the carbonization is relatively low. After years of practical experience, I have found that the Beiyi formula, its aromatic substances after the action of hot water, is the most fragile, if the extraction is not handled properly, it will produce "Jackyl and Hyde change". It should have a sweet smell of espresso, which may become too sour / too bitter or astringent.

As a baking retailer, when you use most of these more fragile recipes, you will face the challenge of insufficient stability in the cup when brewing. Due to the lack of baking flavor substrate in Beiyi formula, if your bar staff is a little careless, the espresso will be easy to detect defects, especially when mixed with milk; when extracted by experts, when mixed with milk, it will highlight the strong caramel flavor in espresso. To me, this caramel flavor is the style and characteristics of Beiyi formula.

Due to the low degree of carbonization of Beiyi coffee beans, it accounts for a high proportion of caramel flavor and regional flavor characteristics. It is a great challenge to retain these rich characteristics during cooking, especially in the stability of cooking water temperature. If the cooking water temperature changes too much (up and down more than four degrees Fahrenheit), the caramel flavor will be the first to be sacrificed. Then came the dull yellowish crema outflow. If the cooking water temperature is stable (the up and down change is less than 2 degrees Fahrenheit), the crema will show ochre red. But the ochre red crema does not mean that the caramel flavor can survive after brewing, even at a very stable temperature, it is often sour espresso, then the water temperature may be low (at sea level, the ideal cooking water temperature is 204 degrees Fahrenheit, the measuring point is near the coffee cake). On the thermostat in my store, I found that the sweeter the espresso, the easier it is for their crema to fall apart.

The Beiyi recipe has many other challenges for professional brewers. For example, the machine must be cleaned very carefully, because beans of the Beiyi formula are particularly easy to absorb the smell from the coffee machine. If the machine is not cleaned properly, the espresso will produce an uncomfortable bitter taste between charred toast and smelly socks after exercise. In addition, it must be stored in the shape of the whole bean and flipped and mixed from time to time. Coffee beans are stored like red wine in a sealed and opaque container at a temperature of about 55 degrees Fahrenheit. In the case of pure arabica beans, beans must be used within 3-10 days after baking, when the crema status of espresso is the most complete. If a high proportion of robusta is used in the formula, the peak of crema may be prolonged, but it must be noted that although robusta beans can provide very thick crema, it is not helpful for sweetness at all. Under the Beiyi baking degree, the vast majority of robusta beans show astringent or woody taste, while good arabica beans show sweet taste.

The bar staff must be very skilled in order to correctly cook the Beiyi formula. If there is any error in cooking or filling, resulting in the "channel" effect, the water flows quickly through this crack, the sweet molecules are destroyed, and the composition of the whole aromatic compound flowing into the cup is out of balance. Finally, the whole cup of espresso is occupied by astringency. In addition, the bar staff must also be careful not to put the espresso for too long. The cooked espresso must be mixed with milk as soon as possible. When making cappuccino, the sweet molecule of espresso is one of the important ingredients to form foam, but this ingredient will soon fade, and ceramic cups must also be preheated to preserve the espresso structure.

One of the keys to getting this seductive sweetness is the flow rate. To deal with this variable, the bar player must first carefully adjust the grinding scale. If the flow rate is too fast, it will be sour and astringent, and if the flow rate is too slow, it will be scorched and bitter. The goal of our store is to extract for 25 seconds, and the state of flow must be like a "mouse tail".

It may take years to cook a Beiyi-style espresso, but if you end up in a neighborhood where more customers like the taste, your business may be much better than other ripe bean retailers in the same community. However, if your goal is to open any type of chain store, do not choose this Beiyi-style baking, practice cooking and try to fail a lot of times, you might as well choose a deeper baking formula, customers are more acceptable. Beiyi recipe is more suitable for baking retailers interested in craftsman level to sell. A coffee lover with talent and great enthusiasm for coffee will be fascinated by the successful espresso of this Beiyi recipe. Once you have successfully mastered the main points of Peiyi recipe, then you are almost unrivalled in the industry.

Chinese baking

When we bake deeper and more sugar begins to be carbonized or burned, this is called synonymous baking, which is usually popular around Florence with this degree of espresso. This kind of formula produces slightly darker beans with a bitter flavor. But the baking degree is not deep enough to burn out all the flavor characteristics of the production area, and the formula of the middle meaning is mainly another type of balance, that is, the combination of bitterness, remaining sugar and flavor characteristics of the production area. There is more or less a hint of smoky aftertaste in Chinese-style espresso.

Using unstable boiling water temperature to extract Zhongyi formula (most espresso machines on the market almost have a water temperature change of more than six degrees Fahrenheit), the espresso of Zhongyi formula still has a stable performance, so this type of formula is the most suitable for general baking retailers and, of course, for high-pole roasters to sell. The advantage of the Zhongyi formula is that in case the bar staff is slightly negligent and the amount of espresso flows down exceeds the standard, the coffee of the Zhongyi formula will still not be sour, thin in texture, or astringent, and will only lack some sweetness compared to the Beiyi formula beans (even if the Zhongyi formula is carefully brewed, the sweetness will not be better than the carefully brewed Beiyi formula espresso). In the Chinese formula, because the degree of carbonization is slightly higher, and carbon itself is a chemically stable ingredient, it doesn't matter what stage of machine is used to brew this kind of formula, or it doesn't matter if you are not careful when making it. Anyway, there must be bitterness caused by carbonization in the cup.

There is a reason why Italian coffee is roasting deeper and deeper to the south. One hypothetical theory is that the amount of spices used by residents and their taste preferences are affected by different climates. Since ancient times, residents in the north have been convenient to preserve food and meat because of the lower average temperature. In contrast, the weather in the south is hotter, so residents have to rely on large amounts of spices to preserve their food. Many anthropologists believe that this has a certain impact on the taste preferences of residents in different regions, and may also explain why southerners prefer more intensive foods and drinks. The application of this theory to coffee explains why southerly coffee tastes more bitter. Of course, these are just theories, which can not be applied in a pluralistic society like the United States. However, if most of your customers belong to the southern ethnic group, you may find that they prefer the taste of deeper-roasted coffee.

Nanyi baking

Nanyi baking is the deepest baking stage in espresso beans. In this kind of espresso, bitterness / carbon taste is the main flavor, overshadowing most sweetness and regional flavor characteristics. Napoli in Nanyi is the representative region, where you can find the deepest baked espresso in the world, leaving only a little sweetness and regional flavor. If you bake deeper, all that's left is probably carbon and bitterness. Because the bitter taste of espresso at this depth is very strong, it will cover most of the sweetness, but the flavor persistence at this time is the highest, which also increases the fault tolerance rate in cooking. With stylized training and machine, plus a professional bar trainer, this kind of espresso can be done. Nanyi-style baked beans are very suitable for use in small espresso bar or small chain coffee shops. A cup of espresso with strong persistence can be made by using any business-grade machine.

When I visited Napoli, I personally tasted the espresso here. I saw that the bar hands there always kept the freshly squeezed half-ounce espresso cups in hot water, and people on the Italian side would add a rub of sugar and stir it quickly and swallow it. I speculated that Nanyi-baked espresso may have to be extracted (ristretto) in a very short time because there is less sugar in coffee beans, and the tradition has been to squeeze fewer doses in order to balance the sugar and bitterness in the cup. Many people think that this baking method, coupled with this brewing method in Napoli, is the most perfect match in the world, but this combination may not be popular in the United States, because Americans prefer to drink large cups of coffee without bitterness!