Why are custard-filled baked goods commonly linked to food poisoning?

Custard-filled baked goods are commonly linked to food poisoning primarily because the custard itself creates an ideal environment for bacterial growth. Custards typically contain moisture, proteins, and sugars, which make them conducive to the proliferation of harmful bacteria, especially if they are not handled or stored properly. When custards are made, they are often heated to a certain point, but if they are not cooked adequately or cooled properly, the remaining warmth combined with their moist nature allows pathogens to thrive.

While options like the difficulty in cooking thoroughly or the presence of raw eggs can play roles in certain situations, the growth medium aspect of custard is significant. If these baked goods are not refrigerated promptly after preparation or left out at room temperature for extended periods, it can lead to rapid bacterial multiplication, increasing the risk of foodborne illness when consumed. Additionally, because custards may not contain preservatives, this further enhances their vulnerability to contamination and spoilage.