INSTANT COFFEE
Instant Coffee is a beverage derived from brewed coffee beans that enables people to quickly prepare hot coffee by adding hot water to the powder or crystals and stirring. Basically, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious of a process at all and there is no strange chemical alteration that goes on. Instant coffee is still pure coffee. You may also hear instant coffee referred to as coffee powder, soluble coffee or crystal coffee. Typically, instant coffee is made with Robusta coffee beans rather than the more expensive Arabica coffee beans. Instant coffee has been widely used for decades because of its convenience as it allows people to make coffee without any equipment.
Since its invention, researchers have sought to improve instant coffee in a variety of ways. For example, some of the early powdered versions did not dissolve easily in water, leaving clumps of damp powder floating in the cup. Coffee aroma dissipates easily, and manufacturers have tried to develop treatments that will make a jar of instant coffee smell like freshly ground coffee when it is opened. More modern manufacturing processes make instant coffee granules that look more like ground coffee. A major goal has been to produce instant coffee that tastes as much as possible like the freshly brewed beverage.
The Manufacturing Process
The manufacture of instant coffee begins with brewing coffee in highly efficient extraction equipment. Softened water is passed through a series of five to eight columns of ground coffee beans. The water first passes through several “hot” cells (284-356°F, or 140-180°C), at least some of which operate at higher-than-atmospheric pressure, for extraction of difficult components like carbohydrates. It then passes through two or more “cold” cells (about 212°F, or 100°C) for extraction of the more flavorful elements. The extract is passed through a heat exchanger to cool it to about 40°F (5°C). By the end of this cycle, the coffee extract contains 20-30% solids.
Filtration and concentration – After a filtering step, the brewed coffee is treated in one of several ways to increase its concentration. The goal is to create an extract that is about 40% solids. In some cases, the liquid is processed in a centrifuge to separate out the lighter water from the heavier coffee extract. Another technique is to remove water by evaporation before cooling the hot, brewed extract. A third alternative is to cool the extract enough to freeze water, and then mechanically separate the ice crystals from the coffee concentrate.
Recovery of aromatic volatiles – Part of the enjoyment of making and drinking coffee is smelling the aroma. During the several steps of the manufacturing process, volatile aromatic elements are lost; they must be returned in a later step to produce an attractive instant coffee product. Aromatics can be recovered during several stages of the manufacturing process. For instance, gases released during the roasting and/or grinding processes can be collected. Ground, roasted coffee can be heated to release additional aromatic gases. Passing steam or appropriate solvents through a bed of ground, roasted coffee can strip and capture aromatic components. Aromatic oils can be expressed from spent coffee grounds by exerting pressure in. Gases can also be distilled from coffee extract after the brewing process is complete.
To preserve as much of the aroma and flavor as possible, oxygen is removed from the coffee extract. This is accomplished by foaming other gases, such as carbon dioxide or nitrogen, through the liquid before it enters the dehydration phase of the manufacturing process.
Dehydration – Two basic methods are available for converting the liquid coffee extract to a dry form. Spray drying is done at a higher temperature, which affects the taste of the final product, but it is less costly than freeze drying.
Spray drying – The spray-drying method of making instant coffee is almost as instantaneous as brewing the coffee. The transition from liquid coffee to instant coffee takes only 5 to 30 seconds. In this method, coffee or concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. Unfortunately, in this process, the high temperatures tend to affect the oils of the coffee and more of the flavor is lost. Also, it often produces too fine of a powder. To make the powder acceptable for consumers, the grains are fused together with additional processing that involves steam. In some cases, the coffee powder is then supplemented with additional flavor and aroma compounds to better simulated fresh coffee.
Freeze drying – The freeze-drying method preserves the most ‘coffee flavor,’ but it’s likely that you will pay more for freeze-dried instant coffee, but the flavor difference is worth it. The coffee or a coffee concentrate (made by freeze concentration) is rapidly frozen to around -40 F (also, -40 Celsius). It’s then placed into a drying chamber; a vacuum is created in the chamber and then the chamber is heated. As the frozen coffee warms up, the frozen water rapidly expands into gas in a process called sublimation. What’s left is dry grains of coffee.
Packaging – Instant coffee particles are hygroscopic meaning they absorb moisture from the air. Consequently, they must be packaged under low humidity conditions in a moisture-proof container to keep the product dry until purchased and opened by the consumer. Also, to prevent loss of aroma and flavor, the product is packaged in a low-oxygen atmosphere, usually carbon dioxide or nitrogen.
Uses of Instant Coffee
- Instant coffee is often used on the go and in places where there is no proper kitchen such as on trains, at drink kiosks, and in offices.
- Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks like hot cocoa.
- Instant coffee is often much more effective at infusing a recipe with coffee-flavor in cooking and baking than fresh liquid coffee.
- Instant coffee is also a major ingredient in Caffenol-C, a homemade developing liquid for black-and-white photos. Interestingly, the cheaper the brand of instant coffee, the better it usually works for developing photos.
- The main byproduct of the instant coffee production process is spent coffee powder. This powder can be used as biomass, for example to produce heat used in the manufacturing process.
Differences between Instant coffee and regular coffee
Each has its own advantage and disadvantage. If you are after convenience, you will prefer instant coffee over regular coffee. If it is the taste that you are after, you may opt to go for regular coffee despite the preparation that you need to do before you enjoy your first cup.
Other advantages of instant coffee include speed of preparation, lower shipping weight and volume than beans or ground coffee (to prepare the same amount of beverage), and longer shelf life. Instant coffee also reduces cleanup since there are no coffee grounds so it has a lower environmental footprint than other preparation methods.
Preparation – instant coffee is very easy to prepare. You do not need to have a lot of time to have the instant mix. You simply have to add hot water and you instantly have your coffee ready to drink. Instant coffee is the type of drink intended for those who are in a hurry. For those who want to enjoy a more premium cup of drink and can dedicate the time to wait for it to be prepared, instant coffee is probably not something they will enjoy. Regular coffee on the other hand has to be brewed in order for it to be enjoyed. You have to prepare your materials and coffee maker and allot of few minutes for brewing time before enjoying it.
Taste – When it comes to taste, regular coffee gives a stronger and bolder flavor, stronger aroma and is full bodied. The instant mix, due to the processes it has already undergone for it to be instant and easy to prepare, loses some of its flavor. You may need to use more to enjoy a bolder taste. The aroma of regular coffee is also more distinct and bolder. The aroma of instant coffee tends to be milder and whether you make a mild or strong cup of coffee, the aroma tends to be the same.
Price – Regular coffee is more expensive than instant coffee despite undergoing additional processing and thus has more operational expense but is still less expensive than regular coffee. The higher premium of regular coffee is primarily due to the taste that it promises to deliver. Coffee, after all, is a beverage and for food and beverage choices, better taste means a heavier price tag.
Caffeine level – Instant coffee generally has a slightly reduced caffeine level compared to freshly brewed coffee. If you’re concerned about getting too much caffeine, this could be a benefit for you. More caffeine isn’t necessarily always a good thing however, as it will impact each individual differently. Decaf instant coffee is made by decaffeinating the coffee beans prior to brewing and powdering them.
Health Effects – There may be a small difference in terms of antioxidants, vitamins, minerals and caffeine levels. The main difference is found in potassium levels, with ground coffee having more than double the potassium of instant. There is evidence to suggest that the antioxidants are comparable in instant and ground coffee, with one study finding that instant coffee actually had more of some antioxidants. We need to remember that we can find high amounts of antioxidants in our fruits and vegetables too however, coffee isn’t the sole source in our diet.
For unknown reasons, instant coffee may decrease iron absorption compared to regular coffee. Normally, the intestines absorb about 5.88% of the iron you ingest. With regular drip coffee, that percentage is reduced to 1.64%. With instant coffee, it’s 0.97%. You can avoid any malabsorption of iron due to coffee consumption by drinking coffee one hour or more before eating. Also, don’t drink coffee for several hours after eating.