Roast Development (by Baristahustle)   



Here’s where we need to start changing habits. Roasting darker does not automatically make the coffee developed. On the other hand, a light roast is not automatically undeveloped. Don’t make that mistake: development is separate to colour. You cannot see true development on the exterior of a bean. This is because a significant amount of the bean’s interior might still be underdeveloped.

Just before, I mentioned that a dark roast can lack sweetness and that a light roast can be incredibly sweet. This is due to development. With proper development, any reasonable colour of roast can be rich and sweet.

A developed coffee has been roasted in such a way that it doesn’t display any undesirable savoury “organic” flavours (stem, corn, grass, peanut shell, capsaicin, wheat etc.) and its structure has been broken down enough for water to be able to enter and dissolve its flavours (soluble). Developing a coffee perfectly is extremely difficult, and eludes most roasters.



Underdeveloped coffee displays those undesirable “green” flavours and is less soluble..

A vast majority of the coffees I am currently tasting from Specialty Coffee Roasters around the world exhibit underdevelopment. Objectively and subjectively identifiable underdevelopment. It’s a real problem in the industry and has far reaching effects, including:
– reducing efficiency of extractions.
– inhibiting customer acquisition or conversion from traditional “dark roasters”.
– it tastes terrible.

Similar to extraction taints, like dryness or sourness, underdevelopment is a generic flavour. You can get it with high or low quality green coffee. Buying expensive green coffee does not justify or mask underdevelopment. We are “Specialty” – we need our customers to perceive and pay for higher quality – underdevelopment makes that difficult.

Underdeveloped coffees behave in a very particular way:
– If you find yourself grinding one coffee significantly finer than another, even though the colour is similar, that coffee is likely underdeveloped.
– If you struggle to slow down espresso shots with a certain coffee but not others, look to development as the cause.
– If you can’t crack open a roasted bean easily with your fingers, it’s likely underdeveloped
– Break open a bean and look closely at the colour of the outside and inside layers of the bean. If there’s a difference in colour that you can perceive, the inside is definitely underdeveloped.

Roasting darker is one way to reduce underdevelopment, but it’s not the best way. Yes, you will expose the interior of the bean to higher temperatures, reduce the undesirable flavours and increase solubility; but the exterior of the bean is now likely overdeveloped and far too dark. There’s still disparity between the inner and outer layers. The only solution is to apply the right amount of heat at the correct times in the roast to develop the inside and outside of the bean evenly. This allows you to finish the roast darker or lighter without fear of under-developing the interior or overdeveloping the exterior. I say again: with proper development, any reasonable colour of roast can be rich and sweet.



Overdevelopment is when the coffee has become soluble and displays no undesirable organic flavours, but the energy and time applied during roasting has left nothing delicious behind. It’s empty, lifeless and hollow. This is extremely rare, nearly impossible with Kenyan and Colombian coffee, and almost never seen in Specialty. Don’t lose any sleep over it.