ask the chef
You've written before about how chocolate can be ruined if a little water gets into it as it melts, but is there any way to save it? It seems a waste to throw away the chocolate just because of a little water. And what if you burn the chocolate and it hardens - is it also unsalvageable?
When a little moisture gets into melting chocolate, it 'seizes' and becomes hard or lumpy, but I've never said it is ruined and must be thrown away. If you were planning to use the chocolate for dipping you'll have to start again, but the seized chocolate can be used for other purposes.
You can 'loosen' the hardened chocolate by adding more fat: melted vegetable shortening, clarified butter, pure cocoa butter or even a little vegetable oil. This will help the chocolate become fluid again and can be used for baked foods such as brownies or cakes.
Another way to save the chocolate is by adding more liquid and turning it into a ganache, glaze or sauce. Chocolate seizes when a small amount of liquid gets into it, but there is no problem when mixing about equal weights of liquid and chocolate. Heat some cream, pour it over the chocolate, stir and it should melt just fine. Strain it through a sieve to remove any lumps.
Chocolate that hardens because it is burned is another problem because it also changes the flavour, not just the texture. You can try stirring in some extra fat, which will loosen it. However, the small burned bits will need to be removed by straining through a fine sieve. Taste the chocolate and if the burned flavour is mild, you can use it for recipes in which the taste is masked by other ingredients. If the burned flavour is too strong, it cannot be saved.
Is it true that potatoes that are starting to turn green are poisonous or is this just an old wives' tale? Why do they turn green?
As with other plants, potatoes turn green because of chlorophyll, which forms when the plant is exposed to light. The potatoes also produce an alkaloid called solanine when exposed to light, stored in the cold (including the fridge) or when conditions are too warm. Alkaloids are poisonous when consumed in high doses. Fortunately, the solanine forms just under the skin and by peeling this away along with any green parts - and then a little more of the flesh just to be safe - the solanine is removed. Potato sprouts also contain high doses of solanine. Dig deep under the surface of the potato to ensure the entire sprout is removed. Solanine has a bitter flavour so if the potatoes you're eating taste a little acrid, throw them away.
