After the nuclear disaster in Fukushima, Japan experienced a food safety crisis, which led its people to make decisions in a situation of uncertainty. In this context, the Knightian differentiation between risk and uncertainty is revisited to show that any risk evaluation includes a certain share of uncertainty. Thus, decisions cannot be based on the rational choice but depend on judgements. As Karpik emphasizes, this “operation of judgement” usually relies on focal points, which he called “judgement devices”. But when uncertainty is not related to a specific object (the safety of one type of food, for example), but to the whole environment, these devices (e.g. food safety standards) can no longer perform their task, as people do not trust them any more. The application of this framework to the food safety crisis after the Fukushima disaster shows that many customers remained unconvinced by the governmental message which stated that risks related to food intake were limited and, thus, tended to reject the traditional judgement devices. Instead, they started to elaborate “new” standards, which may not be safer than the previous ones, but provided consumers with a sense of relief. These standards were also adopted by supermarkets, despite the government’s opposition.