When making colloidal gold using your recipe you say:
7) Reheat to boiling again.
Allow to stand until color change to ruby red is complete. If you have a stirrer, use it. Expect 5 to 10 minutes for completion.
Should we cut the heat when it reaches boiling and let it cool while stiring for another 5, 10 or so minutes?
Being somewhat color blind I am not sure when "change to ruby read is complete" but I can tell when it is getting darker.
Is it easy to boil it for too long?
Thanks