makingandknowing - Preparing natural pigments

Red Lake Pigments

Name: Ana Estrades and Marilyn Bowen
Date and Time:

Location: Lab 216
Subject: Cochineal Lake pigment Recipe for 0.24 g

Mixed the grounded cochineal in a 500 ml beaker and added 300 ml of 0.1M potassium carbonate solution
Boiled for about 15–20 minutes and then filtered the purple-red solution
Dissolved 10 g potash alum in 50 ml distilled water (with heating, gradually placing the glass beaker in the heat, so that it doesn't break)
With the purple alkaline solution still warmed, at around 50 °C, added the alum solution gradually, stirring until there is no further effervescence (though the foam remained)
the pH was only 5, more acid than the recommended 6–7 (probably because I lost some solution when precipitating the beaker to the jar for filtering)
the resulting color is a bright pink!

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ASPECTS TO KEEP IN MIND WHEN MAKING FIELD NOTES

note time
note (changing) conditions in the room
note temperature of ingredients to be processed (e.g. cold from fridge, room temperature etc.)
document materials, equipment, and processes in writing and with photographs
notes on ingredients and equipment (where did you get them? issues of authenticity)
note precisely the scales and temperatures you used (please indicate how you interpreted imprecise recipe instruction)
see also our informal template for recipe reconstructions