Description
Acid-induced coagulation of goose blood proteins creates a velvety, iron-rich soup base.
Technical
Vinegar's acetic acid (pH 2.4-3.4) denatures hemoglobin and plasma proteins, while controlled heat (60-80°C) prevents rubbery texture through gradual aggregation rather than tight coagulation.
Culinary Significance
The technique transforms blood from waste product to luxurious thickener, providing umami depth and nutritional iron in a form more bioavailable than plant sources.
Science
Primary Reaction
Acid denaturation of globin proteins
Parameters
Temperature
72°C optimal
60°C to 85°C range
Time
2.5 hours
1.5 hours – 4 hours
Equipment
Copper whisk (prevents scorching)Non-reactive enameled potBlood strainer (0.8mm mesh)