Coffee roasting technology A complete knowledge of coffee roasting machine

Coffee roasting (coffee roasting) refers to the heating of raw beans to convert starch in raw beans into sugars and acids at high temperature, cellulose and other substances will be carbonized to varying degrees, water and carbon dioxide will be volatilized, protein will be converted into enzymes and fats, and the remaining substances will be combined to form an oil film on the surface of coffee beans, and in this process will produce sour, bitter, sweet and other flavors of coffee. The process by which raw beans are converted into dark brown beans by forming a mellow degree and hue. Because a variety of small changes in temperature, heat and other small changes in the baking process can change the taste of beans, different beans have different characteristics, and baking is a fast operation in a short time, so it is required to accurately budget the baking process and adjust it timely.

Net spoon roasting is the most economical way to roast coffee with a net spoon in the home kitchen. Spoon roasting varies according to the amount of coffee beans roasted, firepower, seed, room temperature, roasting skills and preferences. Take 150 grams of coffee beans as an example, the first explosion is usually about 10 minutes; the second explosion is about 15 minutes. If you feel that the heat is easy to master, you can use a thermometer with a probe to control the baking temperature and baking effect.

The operation method and steps of roasting coffee beans with a net spoon:

1) put the raw beans into a filter with a handle and close the lid. Adjust the fire to medium fire, hold the filter at the top of the fire 20 cm to 30 cm, repeatedly and evenly make a circular swing to make the water evaporate.

2) when the beans are heated for 3 to 5 minutes, a small part of the silver skin begins to fall off and a fishy smell floats out. If the silver skin falls out in large quantities, the dehydration will soon be completed, and there will be a sweet smell. When the sweet taste begins to be slightly scorched, the color of the coffee beans becomes bright yellow.

3) the dehydrated coffee beans continue to bake, making a "crackling" sound, and there is a faint white smoke coming out, which is the "explosion".

4) about 10 seconds to a few minutes after the first explosion, the coffee beans will smoke again and produce a lighter "crackling" sound than the first explosion, which is called the "second explosion". At this time, the smell of the coffee beans is all released, and the roasting process of the coffee beans can be over.

5) after the second explosion, you can choose to continue baking or "baking beans" according to your personal taste. After pouring the coffee beans into the plate, use the cold air of the fan or fan to cool them quickly and bake them.

After baking, once again confirm whether there are secondary beans and unroasted coffee beans, if any, pick out the fried coffee beans and store the fried coffee beans in a bottle or can for 1 or 2 days. Ceramics help to keep the temperature constant, some people use a special "ceramic coffee roaster" to roast coffee beans, because of uniform heating, and easy to control the baking temperature.

The volume of this kind of roaster is small, and the amount of beans should be controlled below 100 grams. If medium heat is used, it takes about 8 minutes for the cold pot to start baking until dehydration is completed, the first explosion is about 15 minutes, and the second explosion is about 22 minutes.

The price of the hand popcorn pot is higher than that of the net spoon, the baking effect is much better than the net spoon, and it is much easier to operate.

1) place the popcorn pot on the gas stove, preheat it over medium heat, and then pour the raw coffee beans into the pot. The amount of beans is about 200 to 250 grams. Do not close the lid of the pot to facilitate the emission of water vapor during dehydration.

2) turn the handle at a uniform speed to start baking, wait until the coffee beans are dehydrated and turn bright yellow, then put the lid on the pot and continue to bake.

3) the cracking sound in the pot begins and the first explosion begins, and continue baking until the second explosion. It is better to control the time at 10-20 minutes, and it is usually best to take about 15 minutes.

4) during the second explosion, the lid of the pot can be opened properly, and the thermometer probe can be put into the pot to control the baking temperature.

5) after reaching the required baking degree, remove the end of the popcorn pot from the fire source, produce beans, and cool with an electric fan.

The roaster of electric popcorn machine takes the place of manual, which is easy to operate, labor-saving and easy, and the quality of roasted coffee beans is uniform and stable. Before using a popcorn machine to bake coffee beans, prepare thermometers, net baskets for raw coffee beans, silver containers and insulating gloves.

1) pour 85 grams of raw coffee beans into the baking room of the popcorn machine, turn on the power switch, and constantly stir the coffee beans with a shovel to avoid uneven dehydration.

2) after about 2 minutes, the dehydration is complete and cover the popcorn machine. The container used to collect the silver skin is placed in the air outlet to receive the blown silver skin. At this time, the coffee beans turn cinnamon.

3) about 4 minutes later, an explosion begins. The duration of the first explosion is 1-1.5 minutes, and the explosion ends when the temperature of the baking room reaches about 420 ℃. If you need shallow baking, you can end the baking at this time, otherwise continue.

4) continue baking, and the second explosion begins 0.5 minutes after the first explosion. At this time, grease appeared on the surface of the coffee beans, and the color turned dark brown.

5) the second explosion time is relatively short, after the second explosion, the coffee beans are quickly poured into the net basket and cooled by an electric fan.

6) after the roasted coffee beans are reduced to room temperature, the residual silver skins are screened out and baked.

This kind of household roaster uses alcohol lamp or gas lamp as the heat source, while the larger one directly uses the flame on the gas stove as the heat source. The advantage of this kind of roaster is intuitive, easy to control the baking degree, easy to clean the silver skin, but the baking temperature is not easy to control.

Operation steps of manual semi-direct fire drum roaster:

1) put the raw coffee beans in the baking drum, the quantity of the raw beans depends on the size of the drum, and then seal the drum.

2) ignite the fire source, shake the handle at a uniform speed, and turn the baking drum to make the beans in the drum turn evenly.

3) after 3-4 minutes of baking, the beans in the jar began to turn yellow and the silver skin fell off, giving off a fragrance.

4) after baking for 6-7 minutes, the beans in the jar turned brown and began to give off white smoke, and began to explode in about 8 minutes.

5) about 10 minutes or so, the explosion ends. If you like the light taste, you can produce beans. Instead, continue to bake and wait for the second explosion.

6) in 12 minutes, the second explosion is completed, and the beans are produced quickly, cooled by an electric fan, and the baking is over.

The operation steps of the hot air roaster:

1) measure the amount of raw coffee beans to be roasted with the measuring cup attached to the machine, place the raw coffee beans in the baking room and close the lid.

2) turn on the power supply, select the appropriate baking time setting on the machine according to your needs, and turn on the switch to start baking.

3) there is a cooling time of 3 to 5 minutes after baking. After baking, the light on the power switch is turned off, and then unplug from the socket after cooling.

4) after baking, remove the top cover, remove the silver skin collection net, and then pour out the coffee beans.