Perfect marmalade

There used to be a poster in the vinmonopol (Shop where you buy wine and spirits in Norway) that said "if you have made jam in the past 6 months then you don't need to show your proof of age", or something like that in Norwegian. This weekend I made marmalade. It has to be about now because Seville oranges are only available in January and real British marmalade needs to be made with Seville oranges or you get something too sweet like the stuff sold in shops in Norway. There's lots of science in marmalade making, first the whole setting thing. I thought it was mainly yo do with boiling away water to increase the concentration of sugar but a quick google reveals it's about polysaccharides and a load of other chemistry so best steer clear of that. Another thing you have to be careful of is not to bottle too soon. If you do the peal floats. I'm not sure why this is but I had to boil my re-boil my first batch because I bottled it too early. Maybe the density of peel is dependent on temp or could it be that when cooled the marmalade thickens so the peel can't move so easily. Would make a good EE topic for someone but they'd have to be quick before the orange season ends. As I am writing this I can hear the tops of the jam jars popping. This happens because as the air above the marmalade cools its pressure gets less causing the atmosphere to push the top in. When you open the top it pops back out again letting you know that no one else has opened it before you.

Anyone interested in making the perfect marmalade can find the recipe here word of mouth blog.