How They Make Instant Coffee

Imagine a coffee that is pre-brewed so you can just add water, light and portable and also long-life. It would be a remarkable feat of science and innovation.

Whilst many coffee lovers will hate instant coffee by default I think it is important to acknowledge the cleverness of instant, soluble coffee because it is a fascinating journey.

What actually is ‘instant coffee’?

A roasted coffee bean contains all the goodies you want, but it needs to be dissolved first. Water is your solvent.

Instant coffee is coffee, that’s been extracted and then reduced to just the solubles.

Essentially it’s pre-brewed coffee that’s been brewed at a ratio so that 1 tsp conveniently becomes the correct strength when 200ml water is added.

maxwell house instantWhen you extract coffee you are dissolving coffee solids in water. Instant coffee is that, with the water then removed: soluble coffee.

The benefit is a portable, light weight coffee with a high shelf life that’s foolproof for the user to make.

Creating instant coffee in the first place is no easy feat. It’s the reduction of a liquid to a solid that’s the hard part. You see, coffee is very sensitive to air, heat and light. So how does one remove the water from the brewed coffee without using air or heat?

These were the questions asked by the instant coffee pioneers.

From Whence it Came

The very first instant coffee was made just down the road in Invercargill. Back in 1890 a Great Southern bloke named David Strang patented a process that simply blew hot, dry air over the liquid coffee until it reduced into solids. Presumably he drank Speights and was a shepherd*

This process, given what we know about what happens to coffee with heat and air would have undoubtedly resulted in heat damaged, oxidised coffee. Portable, yes, but also most likely horrible.

(See the original advertisement for Strangs Coffee, 1893)

Over in the States a Japanese scientist living in Chicago developed the same process and it was sold commercially throughout the States by 1910.

The sheer delight of portable, instant coffee swept through the populace and  companies sought to improve the process and make it less horrible.

The biggest innovation happened during the second world war: Nescafe used the freeze drying process on coffee in order to get it out to the front line.

Originally freeze drying was used for penicillin and blood plasma but coffee is correctly right up there in the list of priorities so came about soon after. In fact, coffee was the first food product to be freeze dried and freeze dried coffee is still available today.

The Freeze Drying Process:

Remember, to make instant coffee we are trying to remove the water from the brewed coffee without using heat and air. In this process, the brewed coffee is kept in a vacuum, frozen and then heated under the vacuum. In the state of high pressure it goes from frozen to steam without boiling with the coffee (called sublimation). Incredible.

This video (starting at 2min55) shows this process:

Freeze Dryers are very expensive.

Spray Drying: a cheaper alternative

While freeze drying is a clever process, it is difficult to do to scale. So another method that was developed around the same time became more common: spray drying.

spray-drying

This is a technology that was used for powdered foods, pharmaceuticals, and chemicals.

The process involves spraying liquid through a very fine nozzle from a great height with air flowing around it.

As the liquid falls to the collector, water evaporates off leaving just the powder to be collected below.

The process takes around 5-30s so the coffee doesn’t have time to oxidise in this process. This is the process used in the Cerebos-Greggs instant coffee factory in Dunedin and indeed the Edendale milk factory in Southland to make milk powder.

So with all the cleverness in making instant coffee, why the hate?

Why people hate instant coffee.

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Many would consider the taste undesirable. This is completely warranted in most cases:

Since there’s an extra expensive process in making coffee soluble, the coffee they use is low quality.

Typically this is Robusta coffee: an easier to grow, more resilient but significantly less desirably flavoursome species of coffee plant. This is what gives the acidity and intense bitterness of instant coffee. And the reason you need to douse it with milk and sugar.

Don’t be fooled by the 100% Arabica claims either – this is the lowest grades of Arabica also go into instant for the same reason: because it’s cheap. Kind of like the off cuts of meat going into pet food.

We are starting to see instant coffee being made from higher quality beans and that do result in a great flavour, but ultimately to appease the masses, one must be generic.

Instant is clever but life’s too short to drink bad coffee.

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