Roasting process of coffee

Roasting brings raw, green coffee beans to a state called pyrolysis, which generally occurs at from 400 ° F to 420° F (204 ° C to 216 ° C) and liberates about 150 to 200 BTUs of heat. The beans are roasted to a light color for 3-10 minutes which weight loss 14 – 17%.

At 212° F the coffee beans turn yellow and lose water, from 248° F to 302 ° F the color changes from yellow to light brown and russet, folds in the beans open and release an essential oils, cafeone. At 392° F pyrogenation is reached.

The loss in weight by roasting depended on the kind of the coffee and the manner in which the roasting was done.

During roasting, vapors formed and cell fragments are removed by suction of an exhauster and in larger plants, incinerated.

Until coffee is roasted, its taste remains unknown. The end product is discharged rapidly to cooling sifters or is sprinkled with water in order to avoid over-roasting or burning and aroma loss.

The cooling was then followed by an air suction operation called ‘stoning’ which removed any stones or other hard material that would damage a grinding mill.

By the time coffee finishes roasting, more than 700 identified compounds cumulatively called coffee flavor – exist.

The most obvious change was production of a fragrance, attributed to a mixture do several substance. It was partly due to the volatile oil called caffeol, which was produced at the expense of other substances and partly to the sugars which were caramelized.
Roasting process of coffee

Roasting

Roasting is often used when preparing succulent meats such as ham roast, crown roast, tenderloins, turkey and rubs.

Roasting is often associated with festive times such as holidays or special occasions.

It is a dry heat method. No water is used, and the meat is not covered, so steam can escape. In principle, roasting meats is a simple procedure. The prepared cut meat is placed in an oven at a selected temperature and it is removed when done.

During roasting a crust is formed on the surface, which preserves the internal part from too sudden or violent a degree of heat and also prevents the draining away of its juice.

Historically, roasting meant cooking meat over an open fire. As time evolved, and the concept developed, meat was impaled onto a spit that turned over the flame.

The Brits perfected this technique in the 18th century one of their culinary claims to fame.

Salt added to the surface of meat just before roasting will penetrate the meat only a fraction of an inch during cooking. The same is true of the flavors of the herbs, spices and aromatics.
Roasting