Wet-aging (vacuum)
7–28 days
Held at 0–2°C in vacuum pack — the path most supermarket beef has already taken. Little moisture loss, meat softens, aroma barely changes.
Dry-aging
21–60 days
Whole joints hung in a room with controlled humidity and airflow. Moisture drops 20–30%, flavour concentrates and a nutty note develops, but the crust must be trimmed and total loss can exceed 30%. That trim is why it costs more.
Only thick, fat-capped joints (ribeye, striploin) work. Thin or lean pieces just dry out.
Leaving meat unwrapped in a home fridge is drying and rancidity, not aging. Safe dry-aging needs dedicated temperature, humidity and airflow.