Cold brew is forgiving, but not that forgiving. If you leave it steeping for 24+ hours in a warm hotel room, you'll over-extract the bitter compounds, which then mask the sourness—but the cup can taste harsh and unbalanced. Worse, some of those bitter flavors read as sour to many people.

Shorten your steep to 14–18 hours. If you're in a warm climate, consider steeping in the fridge or a cooler with ice packs. The goal is a smooth, slightly sweet concentrate, not a bitter bomb.