Honey processing coffee

Honey processed coffee is a method that involves a combination of both the natural and washed methods. It is a rare and demanding method, and not as commonly practiced.

Honey process is a method in which coffee cherries are picked and sorted, have their skins and pulps removed like other types of coffee and moved to patios (or african beds) where it stays without washing off the sticky-sweet outer layer of the fruit.

It remains on the patios to dry until it has reached the desired humidity. During the drying processes the honey process follows the natural method, and the mucilage dries on the exterior of the coffee bean. This remaining mucilage layer gives the coffee a sweet and almost honey-flavored taste, hence the name of the process. And, because of the shorter fermentation period the coffee acquires an acidity halfway between natural and washed coffees.

The flavor components of honey coffees are varied and complex. Like wet method coffees, they have cleaner bodies than dry method coffees. Honey processed coffees have richer notes of syrupy sweetness due to the left-over mucilage.
Honey processing coffee

Freeze drying instant coffee

Instant coffee originates from the coffee tree. The farmer picks the fruit, which is then processed as whole green beans. Manufacturing instant coffee involves roasting and grinding coffee beans exactly like regular coffee.

The ground coffee beans are then dissolved with hot water to extract the flavor and aroma. The coffee becomes powder by taking out all the water through either freezing or evaporation.

In freeze-drying, the coffee extract is frozen to about – 40°C and cut into granules. The smaller frozen granules are dried in a mid-temperature vacuum and under vacuum. The quality of the aroma and flavour are protected by the very low temperature and gentle drying conditions.

As the frozen coffee granules warm up, the frozen water rapidly expands into a gas without it becoming liquid along the way, in a process called sublimation. Sublimation allows frozen foods to be dried without ever having to melt by avoiding a breakdown of cell structure.

Once all the water molecules have successfully sublimed, what is left are dried coffee granules. Finally, the soluble coffee is packaged into either glass jars or sachets.
Freeze drying instant coffee

Wet method of coffee processing

Coffee processed by the wet method is called wet processed or washed coffee. At least 50 percent of all coffee in the world is processed wet, and for most specialty coffee producing countries this is the preferred processing style. It is also the most economically intensive style of coffee processing.

Wet method processing usually involves placing the beans into water for softening and then mechanically de-pulping the beans using a pulper.

In the wet process, water is used to wash the skin and pulp off the fruit of the coffee cherry. The coffee cherries are sorted by immersion in water. Bad or unripe fruit will float and the good ripe fruit will sink. The skin of the cherry and some of the pulp is removed by pressing the fruit by machine in water through a screen.

After de-pulping, the sticky seeds will usually go into a fermentation tank for 12-36 hours. After the fermentation process, the coffee is then rinsed free and clean of any residuals with water.

The beans are then dried out in the sun using either raised beds made of screens, large flat patios, or with mechanical dryers. After these steps, the coffee is rested and then milled, resulting in a clean, polished bean ready for the roaster.

Wet processing in general is said to produce a clean taste in the cup of brewed coffee, and also helps to ensure a shining, bright acidity. The washing process allows consumer to better taste the flavor of the coffee, as washing doesn’t impart a lot of flavors to the coffee.

After a coffee crop is processed and then sorted and grades, most of the coffee beans are usually bagged in 132 or 154 pound coffee sacks.
Wet method of coffee processing

Green Coffee Processing: Dry Method

Green Coffee Processing: Dry Method
Ideally in this process the coffee berries should be uniformly ripened, but often in practice they are harvested by stripping all the berries at once from the trees and collecting them on the ground beneath.

The berries are gathered from the ground and spread out in the sun where they are raked so that they are evenly exposed.

Initially the microorganisms and the enzymes inherent in the coffee berry after the pulp and mucilage. Then the red skin, pulp, mucilage and parchment fuse to produce a thick hull as they dry out.

The coffee is called “pergamino” at this stage. This hull is removed in a hulling machine that simultaneously polishes off most of the silverskin layer.

Both Arabica and Robusta coffees can be processed in this way, but an additional step is necessary for the Robusta beans which have a particularly tough silverskin.

Before the tough silverskin can be removed, the beans must be soaked in water. The moistened silverskin can then be removed mechanically and the beans are dried again before storage and shipping.

The dry method produces green coffee beans much less expensively than the wet method. A high proportion of Brazilian Arabica coffee is processed in this way and almost all Robusta coffees are treated in this way.

The final beverage produced from dry processed coffee has a full flavor that is often described as hard and sometimes is characteristic of a region, for example Rio coffees.

The dry method is generally the less controlled of the two main methods. The stages where extra care could be introduced after harvesting are where the coffee berries may be washed and sorted by flotation before being dried and during then drying itself.

The risk of fungal damage to the berries and consequently to the beans is vey high if the berries are too heaped.

They need to be spread out very thinly, to be frequently raked and not resoaked by rainfall.
Green Coffee Processing: Dry Method

Beverage processing: grinding coffee

Almost all coffees sold are ground industrially by metallic micrometric grinding cylinders assembled in pairs.

Beans must be hard brittle and cold. Grinding is easier when the roasting process was intense. Light roasting yields beans that are soft and tend to be flattened during grinding rather than being reduced to powder.

During grinding, carbon dioxide contained in the coffee bean escapes – this is the degassing of the bean.

The extent of grinding determines in part organoleptic qualities in the coffee.

When the grind is too fine, the procedure for preparing the beverage is long; the water has time to cool so that it draws down particles that sink to the bottom of the cup. The coffee is then muddy and acrid.

When the grind is too coarse, the water filters through too quickly and the coffee’s savor is bland.

During filtration, the optimal rate of extraction is 18 to 22% of the weight of the ground. Ground coffee must be wrapped quickly n order to avoid oxidation and loss of aroma. It is vacuum packed less than eight hours after grinding.
Beverage processing: grinding coffee

Timing of the roasting process

Roasting is a process of exposing the green beans to a heating process that is  rapid enough to drive off the free and bound moisture and later the dry bean is heated above 180 °C to a moisture level of 2 to 2.5 %. The amount of time that the beans remain in the roaster determines the strength and flavor of the brewed coffee in the cup.

Actual contact roasting is no longer importance because heat transfer is uneven and the roasting times required are long (20-40 min).

In the contact convection roasting process (roasting time 6-15 min), efforts are made to increase the convection component as much as possible by suitable process management. Centrifugal roasters, revolving tube roasters, fluid-bed roasters etc. are used either batch or continuously.

In the new short-time roasting process (roasting time 2 to 5 min), the heating–up phase is significantly shortened by improved heat transfer.

What is important is to generate and control the correct temperature at the right moment then stop when the aroma has fully developed and the color of the coffee is homogenous throughout the whole bean.

To cater to different tastes, five different roasts have been developed. It is a rundown from very light to very dark.
*Cinnamon roast
*Regular roast
*City roast
*Dark roast
*French roast
Timing of the roasting process

Industrial processing of green coffee beans

Four methods of industrial processing of green coffee beans are used:
*Roasting, an essential process to develop coffee’s aromatic properties. Roasting changes the appearance, consistency, smell, flavor and composition of the coffee. Roasting coffee beans causes the bean to expand and become more dense, and brings out the natural oils found inside.

*Grinding
When broken down by grinding, coffee cells release their content of pyrolytic gas formed at roasting. This gas is mostly composed of CO2 and CO, accompanied by small amounts of hundreds of volatile chemical species.

The volatiles only present in low concentrations but are essential bringing forth the typical coffee aroma.

*Percolation followed by dehydration to obtain soluble coffee. In percolation process, more coffee beans are used, with a shorter percolation time. This give a strong flavor but avoids the bitterness.

Percolation refers to the coffee making process in which crushed coffee beans are broken up, mixed together, brought into collision and recomposed in a percolator to extract the full flavor of the coffee.

*Decaffeination
Caffeine is removed by soaking the beans on water or by using solvents or carbon dioxide. The last is thought to be the best method as it does not affect the flavor and there is no residue.

Prior to processing, green coffee beans are cleaned and dusted by pneumatic separating machines, then stored in partitioned soils.

Harvested coffee beans begin to ferment almost immediately and if the crop is not to be lost, it must be processed within 8 to 36 hours after picking.

Processing must remove the seeds of the coffee berry – the source of coffee as a beverage – from the surrounding organic material.
Industrial processing of green coffee beans

Coffee Processing: Extracting the Beans

Coffee Processing: Extracting the Beans
Up to a year may pass before newly formed coffee cherries reach full ripeness and are ready for the harvest.

Before the beans become a steaming cup of coffee, they must be extracted from the coffee cherries. Then they must be roasted. And some cases, they must be decaffeinated.

The fruit of the coffee plant is a many splendored thing. The beans are encased in five different layers, The outer skin that holds it all together is thin and a bit bitter tasting.

When fully ripe, the fruit inside the skin is slightly sweet and very similar in texture to a grape.

Next, there’s a slick sticky layer, called mucilage for obvious reasons, which coats a tough paper-thin layer known as parchment.

The final very thin layer is the silverskin, which clings to the beans for dear life.

It’s not easy to release the beans from their five layered prison, but it must be done. There are two means of performing this feat – the Washed Coffee Method and the Dry Coffee method.
Coffee Processing: Extracting the Beans

Industrial Processing of Green Coffee Beans

Industrial processing of Green Coffee Beans
Four methods of industrial processing of green coffee beans are used:

*Roasting, an essential process to develop coffee’s aromatic properties

*Grinding

*Percolation followed by dehydration to obtain soluble coffee

*Decaffeination


Prior to processing, green coffee beans are clean and dusted by pneumatic machines, then stored in a partitioned.
Industrial processing of Green Coffee Beans

Industrial Processing – Dry Method

Industrial Processing – Dry Method
This method, simpler and less expensive than the previous one, is used mainly on small plantations. After sorting out, washing and natural or artificial drying, the end result is a small, shriveled fruit called pergamino.

Whichever method in used, the next step is removal of the hull of the bean.

After another process of sorting out, and subsequent removal of dust, the bean is processed by a hulling machine.

This yield a beam covered with a thin, silvery film which will be eliminated during the roasting process.

The beans then undergo three successive sortings: granulometric, densimetric and colorimetric.

The green coffee can then be stored in bulk or in bags and placed in well ventilated buildings.

At this stage, the producer proceeds with standardization of d the green coffee beans based on their macroscopic characteristics. Beans with the following flaws are eliminated.

• Flaws in from or maturity (beans that are immature, pitted, split, crushed, misshapen, wrinkled or stunted);
• Flaws in color (beans that are black, grayish, silvery russet, white, mottled or spotted);

Flaws in odor (beans that are moldy or mildewed, foul smelling, rancid or have medicinal or chemical odors).

Industrial Processing – Dry Method

Green Coffee Bean Processing: Wet Method

Green Coffee Bean Processing: Wet Method
The production of green coffee beans involves successive removal of the outermost red skin and the pulp of the coffee berry, followed by removal of the mucilage, parchment covering, and finally the silver skin surrounding the green coffee bean.

There are are two methods currently used to produce green coffee beans; “wet” and the “dry” methods.

However, and alternative nomenclature is often used: “washed” and “natural processing”, respectively, and to avoid a misunderstanding it is often necessary to obtain a definition of the processing used on a given batch of coffee beans.

This is relatively intricate and is best carried out with uniformly ripe coffee berries that are still firm.

To achieve this uniformity the coffee berries are selectively handpicked.

As soon as possible they are sorted further in a water flotation system and sent directly to a pulping machine. Here the berries have the outermost skin and pulp removed and the mucilage layer is exposed.

Removal of mucilage ios brought about in concrete fermentation tanks, where the beans are slurried with water, A fermentation occurs that is mainly due to lactobacilli and yeasts.

Enzymes are produced that dissolve away the mucilage. The beans are washed free from the mucilage and the parchment layer is exposed.

Now the beans are dried in the sun or more usually in mechanical dryers.

Hulling completes the process. The parchment layer and most of the silverskin are removed in a hulling machine. Green coffee beans produced in this way are now ready for storage and shipping.
Green Coffee Bean Processing: Wet Method

Preparation and Processing of Coffee

Preparation and Processing of Coffee
To prepare the green coffee beans for market, they have to be removed from inside the berries that have been picked off the coffee shrub.

There are two methods of removing the two hard and pulpy outer layers: “wet” and “dry”. In both methods the seeds are sifted though meshes of various degrees of fineness and then graded and sorted by size.

The WET method
This method is considered at produce a better bean. It is used for the handpicked, quality beans.

With this method, the coffee beans must be extracted from the freshly harvested berries within 24 hours. The berries are cleaned, the husk and pulp are removed, and then the seeds are steeped in fermentation tanks, washed and finally dried.

It is the fermentation stage that gives the beans a superior flavor.

Sometimes coffees made from beans prepared by this method are referred to as “washed coffees” due to the beneficial soaking of the beans.

The DRY method
This produce is sometimes referred to as the “natural” method.

The picked berries are spread in thin layers and dried in the sun or in heated dryers. Sometimes they are heaped first, for a brief period of fermentation.

Once the berries are dried, the pulp is the separated from the coffee seeds by a mechanical husker.
Preparation and Processing of Coffee