📄 Roasting Defects

Tags: #coffee/roasting #roast-profile #quality-control

Roasting defects occur when mechanical failures or human errors disrupt the heat transfer process, ruining perfectly good green coffee.

Common Roasting Flaws

• Underdevelopment: Occurs when the roast ends prematurely before conductive heat penetrates the bean's core. The sugars fail to caramelize, leaving the interior raw. This creates a grassy, hay-like flavor and excessive acidity.
• Baked Coffee: A stealthy defect caused by a "stalled" roast, where beans are heated too long without sufficient momentum to reach first crack. It is invisible to the eye but produces a flat, dull flavor with a grain-like sweetness.
• Overdevelopment / Charring: Happens when the roast is taken too dark or left in the drum too long. It destroys the coffee's natural acidity and caramelization, leaving a burnt, bitter, and ashy profile.
• Tipping & Scorching: Caused by excessively high heat from the roasting drum surface or an overly fast drum rotation. The edges of the beans burn and break off, introducing a bitter, smoky taste while the rest of the bean may remain underdeveloped.