Instant Coffee: How It Is Made, How Much Caffeine, and Is It Real Coffee?

Instant coffee is real coffee. It is brewed from roasted beans in enormous industrial extractors, concentrated, and then dried — either by spraying the extract into hot air or by freezing it and removing the ice under vacuum. Add hot water and you are simply putting back what was taken out. What changes the taste is how hard the coffee is extracted, what is lost in drying, and which beans go in.

How instant coffee is made

Brewing. Manufacturers roast and grind coffee, then brew it on an industrial scale, in what amount to giant drip machines or percolators. The extraction is far more aggressive than anything in a kitchen: water at up to 175 °C under pressure breaks down and dissolves large carbohydrates from the bean that ordinary brewing leaves behind.

Drying. The concentrated extract is then dried in one of two ways.

• Spray-drying sprays the extract as a fine mist into a tower of hot air, which dries the droplets almost instantly into a dust-fine powder. Because that powder is too fine to use, it is steam-fused into larger granules — a technique used since around 1968. Spray-drying is cheaper and suits very large production runs.
• Freeze-drying freezes the extract rapidly, mills it into granules, sifts them for size and puts them in a vacuum chamber, where the ice turns straight to vapour. The granules swell to many times their frozen volume as the ice leaves. It is slower and more expensive.

Aroma. Drying loses a lot of aroma. Since the mid-1960s manufacturers have captured aroma compounds released during roasting and extraction and added them back to the finished product.

The arithmetic of extraction

Here is the detail that explains most of instant coffee's character. In a good cup of filter coffee, water dissolves roughly 18–22% of the coffee's weight; the rest stays in the filter. In instant coffee production, the spent grounds weigh only about twice as much as the soluble coffee produced from them.

Put that as a sum. If the spent grounds weigh about twice the soluble coffee, then the soluble coffee is roughly one part in three of what went in — around a third of the coffee, against a fifth in your kitchen. That is only an approximation, but the gap is the point: industrial extraction dissolves far more of the bean, including compounds a home brewer deliberately leaves behind. The bitter or sour guide explains why the last compounds to come out are the least pleasant.

Which beans go into instant

Much of it is robusta. Robusta makes up roughly 45% of the world's coffee, and most of that goes into instant coffee. It is easier and cheaper to farm than arabica — the arabica vs robusta guide explains why — and its lower acidity, stronger bitterness and woody flavour are a large part of the taste people recognise as instant. Some instant coffees are sold as 100% arabica.

How much caffeine is in instant coffee

The USDA's food database lists instant coffee powder at about 3,140 mg of caffeine per 100 g — about 31 mg per gram. The amount in your cup depends almost entirely on how much powder you use:

For comparison, the USDA's figure for brewed filter coffee works out at about 95 mg in a 240 ml mug, and the NHS uses 100 mg as its estimate for a cup of instant, noting that filter and coffee-shop coffee can contain more. So instant is usually a little lower in caffeine than filter coffee, mostly because people use less of it. The caffeine guide has figures for other drinks.

Is instant coffee bad for you?

The evidence says no more than other coffee, and possibly just as good.

Long-term health. In a 2022 analysis of the UK Biobank, which followed 449,563 people for about twelve and a half years, ground, instant and decaffeinated coffee were all associated with lower rates of cardiovascular disease and death, particularly at two to three cups a day. Ground and instant coffee — though not decaf — were also associated with less arrhythmia. These are observational findings, but they give no sign that instant is the poor relation. The wider picture is in is coffee good for you?

Acrylamide. Acrylamide forms when foods like coffee, bread and chips are heated, and instant coffee concentrates it. EU rules set a benchmark of 850 µg per kg for instant coffee against 400 µg per kg for roast coffee. But a cup of instant uses far less material. At those benchmarks, 2 g of instant carries about 2 × 0.85 = 1.7 µg, while 15 g of roast coffee for a mug of filter carries up to 15 × 0.4 = 6 µg. Per cup, instant is not the higher-acrylamide choice.

Cholesterol. Instant coffee contains negligible cafestol, the oily compound in unfiltered coffee that raises LDL cholesterol. The coffee and cholesterol guide explains why.

A short history

Soluble coffee had some unpromising ancestors. During the American Civil War, the Union army issued a concentrated paste of coffee, milk and sugar called Essence of Coffee, which reportedly had the consistency of axle grease and was soon dropped. Camp Coffee, a liquid essence of coffee and chicory, appeared in Scotland in 1876.

The first powdered instant coffee was patented in 1890 by David Strang of Invercargill, New Zealand, and sold as Strang's Soluble Coffee Powder. The invention was long credited to Satori Kato, a Japanese scientist working in Chicago who showed a powdered coffee at the 1901 Pan-American Exposition in Buffalo, and George Constant Louis Washington marketed his own version from 1910.

The modern product dates from 1938, when Nestlé launched Nescafé, developed by the Swiss chemist Max Morgenthaler. Coffee extract had been too sticky to spray-dry; Morgenthaler's powder was half coffee solids and half maltodextrin, which made it free-flowing. It went around the world in American army rations during the Second World War. Later, extraction at higher temperatures released enough of the coffee's own carbohydrates to spray-dry pure coffee without additives, and General Foods introduced the first freeze-dried instant, under its Maxwell House brand, in 1963.

How to make instant coffee taste better

Use enough of it. Most instant tastes thin because it is made weak. Filter coffee is typically about 1.3% dissolved coffee. To reach that in 200 ml, you need 200 × 0.013 = 2.6 g of coffee solids — about 2.5–3 g of powder, or two to three level teaspoons at the USDA's 1 g a teaspoon. Products containing other ingredients will need more.

Try freeze-dried granules, or a 100% arabica instant, if the flavour is the problem.

Keep it dry. Instant coffee absorbs moisture from the air and clumps or spoils if it is left open. Close the jar straight after use.

Use it where it shines. Instant dissolves readily, so it is the right coffee for camping, for baking, and for drinks built around it, like the shaken Greek frappé and whipped dalgona coffee — both of which rely on instant coffee's near-absence of oil to foam. If you want the freshly brewed version with no equipment, the no coffee maker guide shows how.