ARABICA OR ROBUSTA – WHICH ONE TO CHOOSE?
A Good blend will bring body, mouthfeel, and a certain soft bitterness to the mix. It will also bring a bit of acidity, though on the lower end.
According to the organoleptic macro-characteristics of the main types of coffee, Robusta coffees provide a strong and decisive character to the flavour of the blend, whereas Arabica coffees produce sweeter scented blends, exhibiting fine aromas and taste.
Also, Washed Arabica is a finer and more acidic coffee than unwashed Arabica, which is sweeter and more balanced, while a washed Robusta will have a rounder taste than the unwashed.
– Natural Arabica: sweet, full bodied, balanced;
– Natural Robusta: strong, very dense, woody;
– Washed Arabica: sour, mild, very aromatic;
– Washed Robusta: strong, dense, and chocolaty.
The taste of the blend also depends on the origin of the varieties: a prevalence of Brazilian origins will give a full and chocolaty taste, while central-American origins deliver more aromatic and delicate blends, and an Indian Arabica tends to be full, round, sweet, occasionally spicy or chocolaty.
Coffee Blends are usually of 3 types
100% Robusta: A fully Robusta blend is possible if we know how the coffee is consumed. We can develop a 100% Robusta blend for a milk based beverage as the bitterness that is imminently present in robust is not desired by the mass to be consumed black. But a well harvested and well processed robust can be as good as or sometimes even better than an Arabica.
A Mix of Arabica and Robusta: Full-bodied and bold taste, where the Robusta quality adds body, a bitter note, spicier hints of tobacco and bitter chocolate.
100% Arabica: Sweet and fragrant, where the acidity, the sweetness and the most refined aromas (for example, citric and floral) are highlighted.
In coffee blends, a 100% Arabica is often not the most popular option for customers, as a percentage of Robusta coffee will add strength and creaminess to an espresso, that rarely the Arabica, richer in oils, can give. This is what makes the Italian espresso the most desired beverage.
HOW DO WE GO ABOUT DEVELOPING BLENDS FOR A PARTICULAR BREWING TECHNIQUE?
For starters, let’s look at two popular manual brewing techniques, the Pour Over & the Cold Brew
THE POUR OVER: While developing a blend for the Pour Over, we must first understand that this method of brewing was mostly directed toward brewing of Specialty coffee, where the nuances of coffee could be appreciated at its natural best. This style of brewing is where coffee is consumed all black.
This is a style of brewing where hot water is passed through the coffee grounds and the water passes through the ground and then a filter paper down to a cup. Pour over filter coffee is clean, clear, and consistent. This is because the water is allowed to extract coffee oils and fragrances in its own consistent time and at its own pressure. The filter then catches a lot of oils, leading to a clean cup.
Roast profile: Because the pour over method works well to highlight subtle flavor notes and aromas, you may be required to choose a light roast. Beans that are roasted to this profile are the brightest, with the most acidic flavors.
Grind size: The size of your grounds affects the rate of extraction. Pour over is an infusion method, which means that the coffee and water are in contact for a shorter amount of time than in an immersion method, but longer than in an espresso. So, you want the coffee to have enough surface area to extract before the water filters through into the cup, but not so much that they under-extract and produce a bitter brew.
What this means is that you should start with a medium grind size and then evaluate your cup and tweak it as needed. If it’s a little watery or sour, try a finer grind. If it’s bitter and lacking sweet notes, try going a little coarser.
Invest in a quality grinder to make sure your coffee particles are all ground to the same size. Lower-quality grinders may produce inconsistently ground coffee and a lot of “fines”. These tiny fragments of coffee extract very quickly and can throw your cup off.
THE COLD BREW: This entails a simple process of immersing coffee in cold water and letting it steep overnight, resulting in a concentrate that is smooth, mellow with very little acidity or bitterness. While developing a blend for cold brew we keep in mind that the brew must have a full body and the bitterness and acidity has to not overpower in the final cup.
Roast Profile: The Roasting degree is of utmost importance as the final color of the brew and the extraction will vary a lot based on the Roasting Profiles. African Coffees are known to bring out the desired chocolaty nuance of the coffee in a cold brew preparation. A good combination of Arabica that has been processed differently, or even a blend of washed Arabica and Natural Robusta, could do this. To find the optimum blend that is consistent and easy to replicate, one must be willing to explore all combinations.
Grind Size: The grind size and brewing time have a major part to play in the final cup. To produce a consistent brew, it’s important to keep the grind size and brewing duration constant while developing a blend. Experiment with different grind sizes to see what they do to the coffee and to get a balanced brew.
The next time someone asks casually, “What’s in your blend?” while waiting for their coffee. – Tell them that unless they have at least a half-hour, you’ll give them a little more information each morning for the next week, and then they could get their answer!
Is the Lead for Coffee Academy & Flavour Science at Humblebean
He was the Quality assistant manager at Tata Coffee, and Lead production-in-charge for Roast & Ground and Starbucks operations. He holds a Masters in Coffee Economics and Science (University of Trieste, Italy) Scholarship from Ernesto Illy Foundation. Gaurav will help set up Humblebean’s Coffee lab & academy, and expand our blend development initiatives.