This article contributes to comparative anthropological theory by analyzing the conceptual dynamics of episodic mistrust and selective system trust that emerge from ethnographic cases. Following the cue from recent studies that cast mistrust as a productive category in its own right, we explore this idea in the context of a complex modern society suffering from recurrent food safety scandals. We study how people in China allay anxieties about the food they and their dependents eat. In our cases, mistrust has no anchoring in an ideology of opacity and yet is shown to be highly socially productive as people deploy, anticipate and attempt to alleviate mistrusting attitudes. While constant mistrust may give rise to ambitions of total surveillance and control, the ethnography illustrates the benefits of episodic mistrust for actors when attempting to establish confidence in both personal relations and systems. The cases reveal the existence of selective trust in particular systems, which differs both from trust in direct personal relations and from social trust as measured in surveys. The article concludes that system trust must be qualified and conceptually disentangled from a general social trust, as selective trust in exclusive systems may allay anxieties exactly because it insulates the actor from involvement in more comprehensive systems that are seen as overly risky.