Fe3+-polyphenol dark complexes

Ingredients

Quebrantar Ground galls, White Wine, Caparrosa (FeSO4), Gum arabic, Alum, Indigo, Brown Sugar

Preparation Steps

Original Recipe Text

The Madrid recipe (Table 1, p. 3) employs Quebrantar Ground galls extracted in 100% white wine (22.62 mL per 1 g galls). The iron sulfate is 'Caparrosa'. Ratios for Galls:FeSO4:Gum are 1:1:1. Significant additives include Alum (0.08), Indigo (0.08), and Brown Sugar (0.08). The extraction process involves 9 days at room temperature followed by filtration (p. 3).

Evidence

"Madrid | Quebrantar Ground | White Wine | Caparrosa | 1:1:1 | Alum (0.08)+Indigo (0.08)+Brown Sugar (0.08) | 9 days RT | Yes"

Remarks

Counter-intuitively, 100% white wine was less efficient at extracting phenolics (17.8±0.6 mg/mL) compared to the water:wine mixture in Guadalupe (p. 6, 8). White wine analysis revealed a variety of organic acids and phenolics like tartaric, caffeic, and quercetin glucuronide, which can form or participate in iron complexes (p. 7, 8). The final ink pH with gum arabic was 1.98 (p. 8).