Sunday, September 14, 2014

Specialty Coffee Roasters For Efficiency And Consistency

By Kerri Stout


Coffee beans grown in different micro-climates are distinctive from one another and this is just one of the factors that affects their quality. Plant a great variety in the wrong soil or at the wrong altitude and the resulting product is inferior. Roasting is another factor that affects quality and modern specialty coffee roasters allow for more control over the roasting process. Despite the fact that these machines are usually user-friendly, it takes technical skill and experience to take the best varieties and reveal their full potential by roasting.

The modern, computerized machines used for roasting today are quite different from those used in the past but the basic principle remains the same. Drum and hot-air machines are most commonly used. Drum machines have horizontal rotating drums and the beans tumble around in these while heat is applied. A hot-air roaster forces hot air through a perforated plate or screen under the beans and they are lifted on a currant of air.

The modern machines vary in the level of control that can be exercised. It is possible to operate them manually or use semi-automatic and automatic control. They also vary in capacity with some designed to handle high volumes and others to handle medium sized or small volumes. They have various ways of monitoring times, temperatures and color development.

A green bean is spongy and soft while a roasted bean is crunchy. The color, smell and density is changed by the roasting process. Chemical changes take place as beans are quickly brought to high temperatures. As soon as they reach a certain point, they are cooled down to stop the process. It is a matter of seconds between perfection and a ruined batch.

The variables of the roasting process include factors such as the size of batches and the moisture content of the beans. Various factors are monitored and recorded throughout the roasting process. Time taken and temperatures reached are very important factors.

The beans emit a cracking sound when they are heated. The beginning and end of the first crack and second crack as well as the length of time between the two are usually measured. This is used to determine timing for different roasts. Color changes are noted, the most significant one being when color turns to yellow and the browning process begins. The beans swell when heated but at the same time their weight is reduced.

Various adjustments can be made to better express the sweetness, body or acidity of a particular variety. What is called a roast profile is developed for the different varieties and this helps with consistency from batch to batch. Specialized names are given to favorite roasts. In general, they fall into the categories of light, medium, medium-dark or dark.

More and more people are becoming aware of fine coffees and many specialist companies, both large and small, are springing up worldwide. Some stores specialize in providing equipment for roasting and others supply fine roasts. One can shop for equipment according to type, size and price. A perfect roast is often subjective and there are many varieties at online stores from which to choose.




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