Rock Hard Marmalade

This was my first attempt at orange marmalade and it is rock hard, unspreadable (if that is a word). My ingredients were:

• 877g Navel oranges - peel and pith of two oranges
• 877ml water
• 877g sugar
• 1 x juice of med lemon - 60ml
• 100ml Chardonnay
• 1 TBS dry pectin - I added this as I did the pectin test and it did not solidfy

I cooked the mixture to temp of 107 Celsius and then bottled. Two days later, ended up with cement.
Was there too much dry pectin? Any assistance would be most welcome tks

You overcooked it by a couple of degrees.

104-105.5°C is enough for jam or marmalade according to Kilner (who make preserving jars). BBC Good Food say 104.5°C. This Guardian article quotes one recipe saying 110°C, but all the rest it mentions are 104°C.

It's not impossible that you added too much pectin as well. Fruit cheeses (e.g. Quince cheese) are cooked to a similar temperature but are designed to be sliced.

You may be able to turn it out of the jar by warming the outside in hot water, then slice it to serve (treat it like an open jar after that, and keep it in the fridge)