Could you give us an example of that story?
Fatberg is important because it’s something made by us, and that fascinates people. As a society, we’ve created this unseen growing monster that lives in the sewers, a place that we depend on but never see. It’s also mysterious: it resides underground; and we don’t know exactly what it’s made of.
For me, the fatberg is rather like the portrait of Dorian Gray: it shows our disgusting side. Just as in Oscar Wilde’s novel, it is hidden away, getting worse and worse as we pile the accumulated sins of the city into it: cooking fat, condoms, needles, wet wipes, and of course human waste.
You can tell a lot about society from what it throws away. We have a lot of objects on display in our galleries which were found in cesspits and wells. Collecting waste is not a new thing for the museum to do! We’ve created a family trail of our galleries, so that visitors to Fatberg! can find out more about past Londoners have dealt with their waste.
Fatbergs are also helped to form by the historical infrastructure of London: there’s a chemical reaction called ‘saponification’ where the fat reacts with the lining of the sewers, turning the oil into a soap-like substance. It’s exactly the same process that our grandmothers would have used to create soap: heating up animal fat, then mixing it with ash. In this case, the oil is mostly old cooking oil. That heated oil produces free radicals which then bond with grit from London’s streets. The result can be quite liquid, or, like the Whitechapel fatberg, set like concrete.