Grapefruit Glut - Marmalade

Our grapefruit tree is huge and I don't think we'll ever be able to consume everything it provides.  Heck, I made a HUGE batch of marmalade, numerous cakes, muffins and juice, and we didn't even make a dent.  We're very lucky that our grapefruit are sweet and not overly bitter or tart, you can drink the juice freshly squeezed, no water or sugar added.  I'll miss that once our tree is finished (or when the next storm hits).  In the mean time we can work our way through 19 large jars of marmalade - I made double batch of recipe below.

Marmalade
4 Grapefruit
2 Lemons
3.5L Water  (use only 6L for double batch)
Sugar

Wash then thinly slice or whizz up fruit in a food processor (don't throw away the pips - they have pectin that help the marmalade set).  Cover with water and leave for 8-10 hours.  I chopped mine in the morning and cooked it in the evening once the kids were in bed.

Once soaked simmer for 45 minutes or until soft and pulpy.

While fruit is cooking turn on oven to 120C.  Wash and rinse the jars and lids.  Put jars in the oven for 30 minutes and boil lids covered in water for 10 minutes to sterilise.

Once pulp has cooled slightly measure and add one of cup sugar for every cup of pulp.  Return to the heat and boil rapidly till mixture reaches 105C or setting point (drop a small blob on a frozen plate and put plate in the fridge for a couple of minutes.  Give the blob a gentle poke, if it has formed a skin that wrinkles it's ready).

Carefully full jars and screw on lids - trying to avoid getting jam everywhere like I do.