It may come as a surprise for readers to hear of a virtual "Valley of Death" between differing disciplines for roasting coffee to suit milk-based coffee brews versus a purist espresso (black brew).

In Australia, just over 90% of espresso-based coffees are intended for milk-based beverages. This stat does not change much for whether that is in a cafe, office or home environment.

Cappuccino, latte and flat white beverages continue to dominate the fresh coffee landscape in Australia. It's done so for many years and unlikely to reduce in popularity.

So why do Australian coffee drinkers prefer their milk-based espresso beverages with added elements such as dairy or dairy-alternatives like oat, soy or nut milks ?

Part of the answer lies in the ways our coffee culture is heavily dependent upon medium roasted, high-quality coffees containing greater levels of acidity and sweetness.

In contrast to say Italy where the short black is more popular, perhaps due to the quick convenience and lower pricing compared to a latte style beverage.

In Nordic and Scandanavian countries, there has been a growing trend for even lighter roasted coffees that are brewed in various filter or drip style devices and consumed without dairy or milk-alternatives.

So in Australia coffee brands build their roasting strategies around appealing to the masses, or the broad majority. After all, brands are in the business of achieving commercial success and not trying to win medals with the best tasting coffee.

This means coffee blend development and roast profiles will inevitably lean towards a more basic, one-dimensional objective - ensuring it tastes good in milk (or dairy alternatives).

When you add milk there are two significant changes occurring to the espresso coffee extraction. Firstly, alkaline in the milk affects the PH balance of the beverage (softening acids) and secondly it will change the taste and strength of flavor depending upon the ratio of coffee to milk.

A well-prepared, textured milk also acts as a sweetener and assist or enhance the chocolate notes in espresso coffee. In some instances, the addition or milk or dairy alternatives will hide or mask a poor quality espresso extraction, lifting up the overall cup to make it more palatable.

Most cafe style coffees in Australia are roasted with higher acid levels so that when milk is added it will balance, or "cut through".

But this higher acid from cafe-style coffee beans can present as unpleasant for non-milk espresso drinkers and it's for these reasons some cafe style coffees are typically roasted darker.

Note - roasting coffee darker does not increase flavor or taste.

Around 2013 a new term emerged in the specialty coffee industry - omniroast.

Naturally, like so many other terms used to market coffee it was literally a bit of smoke and mirrors, or a promise and claim of something that was not entirely real.

Omni-roasts were supposed to bridge that divide between espresso coffee black drinkers and the milk-based majority. In other words, it was a mythical solution to any and all coffee problems. A one-size suits all.

But the reality was a little different. Often these omni-roast coffees did not fit in any category and ended up being pointless marketing fluff. In other words, they did not perform as a cafe coffee with milk, nor did they work as a black drinker.

The Australia coffee industry persisted with this mythical omni-roast concept until it dies a slow death. These days coffee are roasted either for filter (light) or espresso (medium, or medium dark).

Of course, each individual coffee brand has their own unique style for how they roast coffee and that folks creates the continuation of confusion for coffee consumers.

One person's medium is another's light in the same way a medium might be called a dark. On and on it goes around in circles.

What has become more rational today are the clearer delineation between espresso roasts (for cafe style) and filter roasts (for alternative brewing) - and that is a good thing because consumers are better educated and informed of the differences.

Over time we have seen a slight but noticeable and gradual shift in the roast depth from medium to a fractionally lighter side of medium across Australian coffee roasters.

Those brands who had historically roasted rather dark have been systematically lightening their roast depth to appeal to more buyers. Similarly, the lighter style roasts are not more popular in cafes with more consumers tending to choose a black beverage over milk or dairy alternatives.

Whilst these trends are neither dramatic or measurable, they are in fact noticeable.

Cafes that aspire to premium quality now seek lighter roasted coffee solutions. This has generated an entire sub-culture in demographic and geographic areas, e.g. in Melbourne the Fitzroy and Brunswick areas well known for specialty coffees are predominantly serviced by a lighter style of roasted coffee.

For visitors ordering a coffee in these locations, they may be surprised when greeted with a weaker tasting brew where there is less chocolate and higher levels of sweet fruit complexity. 

All this demonstrates is a continued evolution of how coffee is prepared and served in markets and one style is not better or superior to the other.

Coffee is a unique ingredient whereby the drinker becomes accustomed to what their palate is tasting. If you drink bitter coffee regularly and then taste a brew which is not bitter it will initially be strange, or different. Similarly, drinking a smooth and creamy coffee will sensitize your palate so that when confronted with a bitter or acidic brew, the differences are magnified.

Roasting coffee is a process to prepare the raw coffee for consumption. 

The roast operator already has a clear plan for what is to occur when the roast is underway. It's never a "fly by the seat of your pants" situation. The roast operator drives the roasting machine to obtain the desired and intended finished product based upon experience and the brand policy for how that particular coffee should be created.

Lighter roasted coffees can lack body when used for cafe-style duty with milk or dairy alternatives added. They can also exhibit high levels of acidity when consumed black if the roast profile was not managed properly. There can also be many other detractors in the coffee when roasted lighter such as higher levels of sourness that can taste herbal, grassy or astringent.

Similarly, medium and dark roasted coffees can have many defects from a poorly controlled or managed roasting profile. Baked notes in the coffee present as "flat" or mediocre lacking acidity, flavor and body or the roasted coffee may have dominant "roasty" notes that are detected in some alternative brew methods.

A good example of "roast" notes in the coffees occurs when a consumer of buyer seeking "lighter style filter roasts" ends up buying a coffee product roasted for espresso. It's when this error occurs that they detect "roasty" notes and subsequently blame the brand for not roasting the coffee properly when in fact they chose a product which was designed and intended for an entirely different brew application.

There is no right or wrong with roasting, just distinct styles and customers need to carefully read the product descriptions to ensure they match their preferences with the product. Sure, it's not easy when trying a new brand where you don't have a point of reference..