Description
Dry-heat activation of spice aromatics through controlled pyrolysis.
Technical
Thermal degradation of lignin and terpenes (e.g. anethole in star anise, cinnamaldehyde in cinnamon) increases volatile oil mobility. Maillard reactions create new heterocyclic compounds like furfural derivatives.
Culinary Significance
Essential for achieving pho's signature depth, transforming raw spice sharpness into rounded complexity.
Science
Primary Reaction
Pyrolysis of phenylpropanoids
Parameters
Temperature
135°C optimal
110°C to 155°C range
Time
110 seconds
75 seconds – 150 seconds
Equipment
Cast iron skilletUnfinished wooden spatulaMesh strainer (for cooling)