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Mike Bullivant's Diary

Day 10: Hand cream

Mike and group pulling wool from the challenge boxI'm making hand cream on the second challenge. Luckily, the fact that we've been given a suitcase full of sheep's wool at the start of the programme is a major clue as to how we're going to go about it. I know that all sheep secrete a waxy grease from their skins, called lanolin. Not only does this waterproof their fleeces, but it also acts as a fungicide and bactericide, protecting the sheep's skin from infection. The challenge boils down to separating the lanolin from the wool, and purifying it in some way.

The initial plan is to wash the fleece in cold water to remove as much of the dirt and grit as possible. I can't imagine that the lanolin will be soluble in hot or cold water, as it's a complex mixture of organic fats. If it were soluble, sheep would have real trouble out here on the west coast of New Zealand, as it rains so much. We can then wash the wool in boiling water, to dissolve up as many of the hot-water-soluble impurities as possible. Being a waxy solid (imagine something between butter and candle wax) the lanolin should melt in the hot water, and being immiscible with it, should separate out as an oil on the surface of the water – a bit like what you'd get if you added a pat of butter to a pan of boiling water.

Mike boiling woolAfter filtering any undissolved matter from the hot solution, we'll cool it down, whereupon the lanolin should solidify out as a greasy, yellow wax. That's the theory, but, as ever, Nature will probably have a different idea.

True enough, by the end of Day 1, all we're left with, after all the boiling and filtering, is a pot full of dirty water. There's no lanolin floating on the surface, so maybe it is soluble in water. Not too worried though, as we know that if there's lanolin in the sheep's wool we've been given, most of it will have been extracted and it'll be in the water. What's more, we still have two more days to go.

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Photo: Mike Bullivant
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