Roasting Coffee Beans

Coffee roasting technology

Several centuries ago, humanity used coffee in a completely different way than it does now. And these days, some Africans make wine from coffee berries, dry coffee leaves and flowers, and brew coffee tea from them.

Raw coffee berries are mixed with bananas and consumed as a pleasant treat.

It's been a while since people discovered a way to roast coffee beans. It's amazing how grains devoid of aroma begin to smell when fried!

Roasting coffee & mdash; one of the main and most important stages in the transformation of grains into a drink.

Raw coffee grains vary in shades from light brown to whitish green. They become brown only after frying. Exposure to temperature allows you to release the taste and aroma of coffee beans.

In the process of frying under the influence of high temperature up to 200 & deg; & mdash; 230 & deg; C, chemical processes occur in the grains, they change color, increase by about 50% in volume, while losing 15 & mdash; 20% of their mass due to moisture loss.

The total amount of soluble substances decreases, mainly due to a decrease in the content of sugars, fiber, due to the decomposition of tannins & mdash; source of tart and astringent taste of coffee. Chlorogenic acid decomposes, forming other acids.

In fried grains, sugar caramelization occurs, which gives them a dark brown color. The decomposition products of various compounds form a coffee pot & mdash; a complex mixture of many compounds.

It is the coffee beans that owe the roasted coffee their specific aroma. In total, more than 400 volatile substances are formed during roasting, of which, in addition to coffee, more than 220 components are involved in creating the aroma.

The B vitamins found in coffee beans are almost completely preserved.

The coffee roaster has a big responsibility. It depends on his skill whether he will give the grains the desired taste or destroy them, because the difference between the average and strong degree of toasting can be several seconds under certain conditions!

Frying is usually carried out evenly, and for this it is necessary to mix the grains all the time. Frying speed is critical.

Too slow frying leads to low extractiveness, and as a result, to a less aromatic drink with poor taste.

Frying too quickly can char the grain surface, possibly leaving the interior unroasted.

Over the past 50 years, increased coffee consumption has consistently encouraged industrial roasting, in which coffee beans are cleaned with a sieve with holes of different sizes, air purged and metal impurities removed with a magnet.

Green grains are then loaded into a drum that is exposed to very high temperatures from the outside in a very short time (approximately five minutes at 200 & mdash; 260 & deg; C). & nbsp; In this case, the grain continuously moves.

When coffee reaches the desired color, it is cooled by air jets (and sometimes water) to prevent overcooking.

Air cooling of roasted beans, unlike water cooling, has almost no effect on the taste of coffee, which cannot be said about water cooling.

It is clear that the best grains are naturally cooled in air.

Degree of roasting coffee beans

Different styles have developed over the centuries roasting coffee.
Depending on the origin of the grains and the place of frying, the American, Spanish, Greek, Viennese, Oriental, Italian style of frying, etc.

These classic style names mean not only the degree of roasting of the beans, but also the origin of the coffee.
For example, the characteristic name & laquo; Italian coffee & raquo; denotes an Italian-roasted blend of Arabica coffee from Colombia and Robusta from Africa.

Strange, at first glance, the name & laquo; Mexican French & raquo; (mexican freuch), belong to Mexican coffee roasted in French.

They tried to eliminate the confusion when recognizing frying styles by setting a special scale with the numbers of the degree of frying and the origin of coffee beans.

However, it turned out that this scale is not enough, since each taster approaches the concepts of & laquo; strongly & raquo; and & laquo; weakly & raquo; roasted coffee.

It was agreed that the grains fried by French, Italian, Spanish and Cuban methods are always dark in color and shiny.

Weak and medium roasted grains are always matte, brown, amber, light brown and chocolate colors.

Since coffee of completely different taste can be obtained from the same beans by frying, additional frying characteristics have been introduced:

• Normal;
• Complete;
• Normal;
• Perfect;
• Special;
• Strong;
• Standard;
• Deep, etc.

To attract buyers, large firms have introduced another term for intermediate frying stages. The result is a rather long list of fried grains from light to very dark in color. The origin of the grains does not matter.

There are several degrees of grain frying.

Depending on the countries and companies producing coffee, they have different names and characteristics. However, there are a number of the most common degrees of frying that you have to deal with most.

 

Lightly roasted coffee

Taste: & nbsp; acid tones are clearly different.

Roasting is used to obtain it:

• New English Roasting ;
• Cinnamon roasting & nbsp; *.

* Cinnamon itself has nothing to do with roasting: only its color is used to indicate the style of lightly roasted coffee.

In this case, the surface of the grain acquires a light brown color. It becomes dry.

Suitable for soft grains, as it allows you to fully manifest fine taste and aroma.

Recommended for coffee drunk at breakfast because it works well with milk.

Medium roasted coffee

Taste: & nbsp; stronger, richer, sweet and sour.

This is the usual degree of frying, roasting is used to obtain it:

• American roasting;
• Regular roasting;
• Medium-high frying;
• Medium roasting.

The grain has a dark color and a dry, oily surface.
The result is coffee that can be drunk at any time of the day, with or without milk.

Highly roasted coffee

Taste: & nbsp; less acidic than medium roasted coffee.

Roasting is used to obtain it:

• Roasting City ;
• Roasting Full City ;
• Vienna Roasting & nbsp; * *;

* * It is difficult to give an unambiguous description of the Vienna frying style, since there are several frying styles in Vienna, all of them are united by the term & laquo; Viennese & raquo;;
often it is a mixture containing grains fried in the style of & nbsp; Full City & nbsp; (two-thirds medium roasted coffee) and & nbsp; French & nbsp; (one-third high roasted coffee), weak French, velvet roasting styles.

The grains are dark brown, and there are slight traces of oiliness on the surface.
Brewing produces a dark drink.

Highest roasting rate

Taste: & nbsp; bitter and very expressive, slightly & laquo; scorched & raquo; and nice.

This category of roasted coffee can include a fairly wide range of different roasting styles, including:

• French roasting;
• Italian roasting;
• Spanish roasting;
• European roasting;
• New Orleans roasting;
• Continental roasting;
• Double roasting,
• Cuban roasting, etc.

With this degree of frying, the grains have a dark brown color and an oily surface, and the dark brown color often turns into black-brown, resembling burnt.

Such coffee is drunk black, with cream, at lunch or in the afternoon, and it is called & mdash; afternoon.

Roasting espresso beans

Black grains, on the verge of charring.

This special category of roasted coffee includes Italian, Indian styles, suggesting the strongest degree of roasting.
Their surface is shiny, oily. It is advisable to grind such beans very finely, which is usually done for espresso coffee.

External coffee roasters