Why does the coffee smell so bad? What are the properties of the aroma and aromatic substances of coffee

When we walk into a cafe, we are easily attracted by the aroma of coffee in the air, especially when grinding coffee beans. We can't wait to order a pot to feel the aroma of coffee.

However! The moment the coffee came into the mouth? What is this? Is the fragrance of flowers and fruits I just smelled fake?

The illusion caused by smell and taste

First of all, we should mention our sense of smell and taste. The sense of smell is divided into the sense of smell in front of the nose and the sense of smell in the back of the nose, which refers to the external smell we smell, while the sense of smell in the back of the nose is felt when the diet passes through our mouth and exhales through the nasal cavity.

Taste includes signals from the five senses (sight, hearing, smell, taste, touch) to the cerebral cortex, which are processed by the central European nervous system, so all five senses are a medium of taste.

They tend to give us the illusion of "what you smell is what you get". The smell is not consistent with what you drink because of the different nature of the aroma you smell and drink.

Aromas of different natures

1. Volatile aroma

The aromas we smell at the beginning are actually coffee aroma substances, because most of them are volatile, so we can sense them with our sense of smell.

We grind coffee beans, flowers, fruits and other sour aroma because of the light molecular weight, with a high degree of volatility, is the first to be released, in grinding, we can smell this kind of smell. Followed by the medium molecular weight of nuts, almonds, caramel, chocolate and other flavors, they float a short distance, need to get closer to smell.

Finally, the bowl will leave high molecular weight turpentine, spices, burnt incense and other flavors, because the molecular weight is too large, we need to stick our nose to the coffee powder to smell it. The above belong to the dry aroma of coffee, because some volatile aromatic substances can not be gasified at room temperature, need to be brewed with hot water to release their aroma, that is, the wet aroma of coffee. Second, water-soluble taste another part of the aromatic substances are both volatile and water-soluble, so we can smell and drink. The aroma will gradually vaporize and volatilize, and with the end of the cooking process, less and less smell can be smelled, so it is time for our sense of smell behind the nose and tongue to come out.

What we feel at the entrance of the coffee: this cup of coffee is sour or sweet, and these tastes are conveyed to us by water-soluble flavor factors. By the way, a small number of substances are only water-soluble, and we can only feel them with our sense of taste. For example, bitter and salty flavors, which we call all evil, can not be smelled because they are only water soluble. This is the reason why a cup of coffee can only be judged by drinking. Third, the different feelings of sour, sweet, bitter, salty and fresh brought about by the flavor combination are the five flavors we can feel. The most common aroma substances of coffee are sour, sweet, bitter and salty. These four flavors can blend and contain each other. When one of the flavors is too prominent, it suppresses or blesses the expression of the other flavors, and eventually affects the tasting experience.

Let's take the sour and sweet taste of diced fruit as an example: when the sour ingredients are lower than the sweet taste, you may taste fresh lemon green tea in flavor, while when the sour taste is greater than the sweet taste, it will evolve into a full sense of juice. Coffee has more than three hundred aromatic substances from the beginning of raw beans, and through the chemical reactions in roasting, it can eventually evolve into more than 1000 aromatic substances. At this time, we can feel the delicious aroma of these combinations by virtue of our sense of smell before and after. It's a great pleasure for us to drink coffee. -END-

Front Street Cafe

No. 10 Baoqian street, Yandun road, Dongshankou, Yuexiu district, Guangzhou, Guangdong province