Never heard of using camelias for this. Interested to hear how it goes though.
Cordial's pretty simple, it's just infused water added to a thin sugar syrup.
So, make strong tea and add sugar syrup......500g of sugar to 1lt of water/tea.
Heavy syrup is 500g of sugar to 250ml of water.
More sugar, the better the preservation, but it needs an awful lot of diluting down to be drinkable, and dilution works on the taste too, so it can end up too 'thin', iimmc ?
To be honest, if the flowers are flavourful and/or colourful, I think I'd just dry them and use them for tea.
M
Should of added, you can sugar flowers to preserve them too, usually ones like violets.
You can also steep the flowers directly in the sugar syrup, but sometimes that overcooks them and gives an odd taste. I was most disappointed in rose petals done that way.