What You Need to Know
Hydrodiffusion and osmosis allow volatile oils (e.g. anethole from star anise, cinnamaldehyde from cinnamon) to transfer through cheesecloth while trapping insoluble particulates. The cloth's pore size (typically 50-100μm) prevents cellulose fiber release.
Essential for achieving clear, aromatic pho broth by preventing spice sediment while allowing full flavor development.
Key Parameters
Temperature
90°C
85°C - 95°C
Time
3 hours
2 hours - 4 hours
Equipment
Unbleached cheesecloth (grade 40)Cotton twine (food-safe)Stainless steel mesh skimmer
Steps
- 1.
Pho Bac (Hanoi): Defines the broth's crystalline clarity
The Science
Primary Reaction
Selective dissolution of non-polar compounds