Which beer is known as "liquid bread" during fasting periods in the past?

"Dopplebocks" is known as "liquid bread" because of its high nutritive value and rich malty flavor, which made it a sustenance choice during fasting periods, particularly in the context of religious observance. Historically, these strong lagers were brewed in Bavaria, and their high alcohol content and robust nature offered sustenance to monks who were fasting or had limited food intake. The brewing of dopplebocks often coincided with Lent, when many religious individuals would abstain from solid food.

The term "liquid bread" reflects the beer's caloric and nutrient density, positioning it as a suitable substitute for solid meals, especially in contexts where access to food was constrained. This significant historical backing solidifies the connection between dopplebocks and their designation as a nutritional beverage, making this option the most fitting answer to the question.