The Riedel Tasting Glass measures precisely the amount of wine poured by filling the hollow stem. The quantity of 20ml allows pouring 35 portions from one bottle. Swirling the wine in the glass enables evaluation of the "nose". To maximise the aeration space in the Riedel Tasting Glass, lower the glass gently into a horizontal position. The wine will flow from the hollow stem to fill the bowl to just half an inch below the rim. Because of its shape, no wine will be spilt. A 360-degree rolling rotation will then create a very thin layer of wine on the complete inner surface of the bowl, maximising the evaporation surface and detailed olfactory information. The larger volume of the glass offers the wine more aeration space, which improves the intensity and complexity of the aromas. In addition the wider mouth of the glass allows the wine to be sipped more comfortably, and avoids tilting the head too far back. The available quantity of wine is sufficient for two sips: the first to evaluate the wine and the second to confirm the evaluation. The distribution of the wine flow is guided mainly to the front part of the tongue, emphasising the fruit. The delivery to the sides and back of the tongue accentuates acidity and the bitter components, allowing the wine to show all its flavours in a harmonious and balanced way.