The Effect of Serving Temperature on Red Wine Aroma

Countless studies have shown that the serving temperature of wine is critical in terms of what aromatic attributes are notable and which are diminished.  In other words, the temperature at which you serve your wine could make or break your overall enjoyment of the libation.  Specifically, serving temperature can affect the presence and intensity of certain aromatic characteristics.  In general, it is recommended that red wine be served somewhere between the mid 50’s (^oF) and low 60’s (^oF) depending upon the varietal or blend, and it is recommended that white wine be served somewhere in the 40’s (^oF).

“Room temperature” is often too warm for reds, as we tend to keep our rooms much warmer than they did when the room temperature rule was created.  If you don’t have a temperature-controlled wine refrigerator, put the bottle of room temperature red wine in the refrigerator for 10-20 minutes to drop the temperature down to ideal red wine serving temperature. Also, refrigerator

temperature tends to be a little too cold for white wines, and one should let the wine sit out at room temperature for 20 minutes or so to achieve optimal white wine serving temperature.

Previous studies have found that sensory thresholds of basic taste characteristics such as salt, bitter, sour, and sweet vary with changes in temperature.  Other studies have found that not only is the temperature of the food or beverage important in how the item tastes, but the temperature of the tasters tongue and mouth also influences what taste characteristics are more notable.  In addition to these basic tastes, studies have shown that temperature also changes the specific aromatic and sensory characteristics of a particular food or beverage.

The purpose of the study presented today was to use  projective mapping or “napping” as a method to determine how serving temperature influences the sensory profile of red wine.  Napping is a method that allows less sensory training for the panelists involved, and utilizing the panelists’ own knowledge and terms related to taste and not a set vocabulary only known to experts.  In other words, when panelists are presented with particular foods or beverages, they arrange the items on a tablecloth or napkin and group them in a way such that “like” items are grouped with “like” items and “non-like” items are kept separate from “non-like” items.  Think of it as a visual cluster analysis, if you will.

The authors of the study presented today hypothesized that serving temperature would affect the aromatic intensity of red wine and that increasing temperature would serve to increase aromatic intensity.  Also, they predicted that there would be a moderate effect of serving temperature on bitterness and astringency, with increasing temperature resulting in decreased bitterness and decreased astringency.

Methods

6 Lemberger wines from Washington State were used in this study.  Wines were stored at 5^oC in the dark until use.

The sensory panel included 8 women and 4 men between the ages of 25 to 65.  Panelists were recruited from Washington State University and were regular red wine consumers.  The study took place at the Washington State University Sensory Evaluation Facility.

In addition to tasting the wines, panelists were asked to fill out a demographics survey.

Sensory analysis took place at isolated tables under white light and at room temperature.  Wines were served in Styrofoam cups, as according to the authors they did not contribute any sensory impact on the wines and the color intensity between the wines were the same when served in the cups.

Prior to sensory analysis, panelists received a basic training in evaluating the intensity of aromatics, mouthfeel, and flavor characteristics of Merlot wines.  Panelists were also trained in the napping procedure first using pieces of chocolate, then again using Merlot wine.  Panelists were trained to group samples according to sensory similarities and to place those with similar characteristics closer together and those with different characteristics further apart.

For the analysis of the Lemberger wines, the wines were kept at three different serving temperatures: 10^oC (50^oF), 16^oC (60.8^oF), and 22^oC (71.6^oF).

Unsalted crackers and deionized water were supplied to panelists for cleansing their palates.

At each temperature, all 6 wines were presented to the panelists in 25mL samples in Styrofoam cups and covered with Petri dishes to keep aromatic volatile compounds from escaping into the atmosphere.  Panelists were then asked to separate the wines using the napping method.  After separating the wines using the napping method, panelists were asked to write directly onto the tablecloth different sensory characteristics that characterized each of the groups that they created.  A wine tasting glossary was given to the panelists to help with this task, though they were also allowed to use their own terminology if they preferred.  Each tasting session was replicated for a total of 6 tasting sessions for each serving temperature.

Results

• There was greater variability between replicates in the composition of wine “groups” at the lower serving temperatures (10^oC and 16^oC) while wine group composition was exactly the same for each replicate at the higher serving temperature (22^oC).
  • The authors attributed this finding to previous studies that suggest that bitterness is more obvious at lower temperatures. Also, since panelists may vary in their ability to detect bitterness, there may be more variability in how each panelist groups each wine compared with warmer temperatures that don’t affect bitterness intensity in the same manner.
• Sour tastes were more prominent in wines served at 10^oC than at 22^oC with wines served at 16^oC falling in between the higher and lower temperatures in regards to the number of sour tastes noted.
• Sweet tastes were more prominent in wines served at 22^oC than 16^oC, with wines served at 10^oC falling in between the two.
• Wines served at 10^oC were more often described as bitter compared to wines served at 16^oC and 22^oC.
• Wines served at 10^oC were described as thinner and smoother than wines served at 22^oC.
• Wines served at 16^oC and 22^oC were described as more viscous than wines served at 10^oC.
• Wines served at 10^oC and 16^oC were described as more astringent than wines served at 22^oC.
• Wines served at 16^oC and 22^oC were described as having more spicy and berry characteristics than wines served at 10^oC.
• Wines served at 22^oC were described as having more leather aromas than wines served at 10^oC and 16^oC.
• Aromas did not appear to be as intense in wines served at 10^oC than they were in wines served at 22^oC.

Conclusions

The results of this study indicate that, as we already know from other studies, serving temperature has a significant effect on the sensory characteristics of red wine.  The results also showed that there appeared to be more variability in what individual panelists were able to detect in wines served at the lower temperatures than in wines served at the highest temperature (22^oC).  Overall, the wines served at lower temperatures tended to have more sour and astringency characteristics than wines served at the higher temperatures, and also were lower in aromatic intensity than the wines served at higher temperatures.

What is not clear from these results was whether or not the panelists preferred one particular wine over another, though it was clear that there were obvious sensory differences between the different temperatures.

It is important to note that the exact sensory changes due to temperature seen in this study are only applicable to the Washington State Lemberger wines tested.  Other studies have found that temperature affects different wines in different ways, so exact aromatic and basic taste changes may be different from one varietal to another.  I think what it important and what is globally generalizable is that serving temperature in general does affect the sensory characteristics of wine regardless of varietal/blend.  What wasn’t discussed in this study was whether or not certain temperatures were more desirable than others in regards to acceptability and liking, but it could come down to personal preference.

What do you think of this study? What other tests would you have liked to have seen performed?  Please feel free to comment!

Source: Ross, C.F., Weller, K.M., Alldredge, J.R. 2012. Impact of serving temperature on sensory properties of red wine as evaluated using projective mapping by a trained panel. Journal of Sensory Studies 27: 463-470.