How to tell a wine is spoiled? – Part 2

With increased interest in wine spoilage, I thought it is timely to give a brief overview on how to determine if the wine is of good quality and if it is spoiled. The basic steps in assessing a wine are as follows: Appearance, Nose and Palate. This is generally applied to a wine that has been poured into a glass and the drinker will focus on these three aspects of the wine. However, when you are in a restaurant or at your own home hosting a dinner party for instance, it may be a little late to figure out if the wine is spoiled after pouring it into the glass. After all, you do not want to be seen serving bad wines. So, there are some simple observations prior the standard 3-step assessment technique.

First, before removing the bottle seal, observe the general appearance of the bottle. If there are wine stains originating from the opening of the bottle, especially if the seal is damp, we can almost be sure that the wine has been exposed to oxygen either due to poor storage condition or the use of poor quality cork. In the case of screw-cap, it may be rare to see this but if there is slippages of wine through the cap, it means either the bottling machine or the glass bottle is not made to specification.

Second, check the level of the cork at the bottle opening. If the cork has been lifted a little, i.e if it is not sitting flat in the bottle opening, it strongly suggest bad storage condition e.g the wine may have been stored in a warm room over an extended period of time. The result could be an oxidized wine and you can pick up the wet cardboard smell upon nosing.

Third, look for the condition of the label on the wine bottle. If the label is crumbled and is not pasted onto the surface properly, it again suggests that the bottle has gone through some temperature swing from warm to cold and vice versa. This alone does not suggest that the wine is spoiled, just that the wine has not been treated with proper care during its shelf life.

Once you are satisfied that the exterior is looking good, we can at least be confident that the wine has been handled properly thus far. The next step is of course to open the bottle and pour a small portion into the appropriate wine glass. The first thing is to study the color and the clarity of the wine. If a wine is too light in color (for a young Red wine) or if it is excessively brown (for a young white wine), it may suggest an inappropriate application of sulfur dioxide. However, the appearance is not conclusive and is only a data point to be considered in subsequent tasting. Clarity is important. If the wine is murky, it is generally not a promising start, especially in white wine. There are some winemakers who opt not to filter their wine (especially Red wine) but the wine should not look murky.

To nose for any spoilage, you will be looking out for odd odors such as rotten eggs or garlic (H2S), bandaid (Brettanomyces), wet cardboard (oxidation), corn chips or metallic bitter finish (high pH wines), moldy or musty (cork taint), nail polish or vinegar (high volatile acidity). Most of these are a result of poor winemaking techniques or barrel storage conditions. However, oxidation may be a result of poor transportation or storage conditions especially when loads of wines are being transported in un-refrigerated container by sea over summer. The heat in the ship storage area over an extended period of time may have the corks expanded and not sit properly in the bottle opening.

As for the palate, a spoiled wine normally gives a SHARP attack to our taste buds or leave behind a trail of very unpleasant finishing. Wines with high volatile acidity will attack our throat like we have just had a mouthful of vinegar. Unusual bitterness is also an indication of spoiled wine, suggesting the presence of spoilage micro-organisms when the wine pH is too high.
In general, a wine is safe-guarded by observing an acceptable range of pH, acidity, alcohol and sulfur dioxide. Unfortunately, during the winemaking process, infections can occur if equipments are not sanitized carefully, storage conditions are not proper. Even if the wine is of good quality upon bottling, transportation and cellaring conditions can also affect the final quality.


Copyright of Wine Treasures Pte Ltd

By Cher Lim
Wine Treasures Pte Ltd
http://www.wine-treasures.com/
Email: cher.lim@wine-treasures.com

Chilling white wines with salt?

Last weekend, I was hosting a party at home and some of my guests decided to arrive earlier to help me in my preparation. I suddenly realized that I am racing against time to cool down the white wines. Then, I remembered my college Physics about how salt will lower the freezing point of water (don’t ask why I thought of Physics in the middle of cooking), I quickly emptied half a packet of salt (the small packet that you can find from Cold Storage) into three wine buckets filled with ice cubes and some water. I left the 4th bucket with just ice cubes and water. With two digital thermometers that are always there to ensure that the wines are served at the ideal temperatures, I asked my guest take readings of the temperature of the two buckets – with and without salt. The results seem to prove that this theory has a direct application in this occasion. Here’s how it works:

First, we must all agree that water freezes at 32 degrees Fahrenheit (0 degrees C). So, those ice cubes we have in the bucket are supposed to be at the water freezing point. When salt is sprinkled onto the ice cube and water mixture, it lowers the freezing point of the mixture to below 32 degrees Fahrenheit. So, ice cubes will begin to melt. As the salt water is diluted in the process, the freezing point start to rise and the water will refreeze but this time, the equilibrium temperature is lower than 32 degrees Fahrenheit. Theoretically, the more salt we add, the lower the equilibrium temperature.

Now, back to our ice bucket experiment. I asked my guest to take temperature readings of the two different buckets in an interval of 1 minute for 10 minutes to get a statistical representation. The salted water bucket has an overall lower temperature than the unsalted water bucket. The delta is about 2 degrees C, and what impact does it have on the wine bottles? I suppose the ‘salt water bucketed’ white wine will be cooler than the ‘unsalt water bucketed’ white wine. Well, my guests seem to agree and we used up all the salt in my kitchen throughout the night!

Copyright of Wine Treasures Pte Ltd

By Cher Lim
Wine Treasures Pte Ltd
http://www.wine-treasures.com/
Email: cher.lim@wine-treasures.com

Storing wine in sunny Singapore

Wine storage always revolves around three important components: Temperature, Humidity and Environment. The proper storage temperature for all wines should be cool and constant (10C-15C). Extreme heat or cold will damage the wine. Bottles should always lie on their sides so that the wine can touch the cork and constantly to prevent it from being dried up. A dry cork will shrink and allow oxygen to enter the bottle and oxidize the wine. Although in today’s bottling technology, screw caps and synthetic corks are often used to replace the traditional wooden cork and may alleviate such concerns. Finally, wines should be kept away from strong sunlight or artificial light which will heat up the wine, causing it to taste stale and old. Wine should also be kept away from any form of vibration, they should not be disturbed as much as possible.

In Singapore, the climatic condition is especially unforgiving when wine is kept in the open, even though they may be in an air-conditioned room. The coolest spot in the house is the marble floor. In the absence of a wine cooler or a refrigerator, unopened wine bottles may be “stored” by placing them (on the side) on the marble floor where the sunlight cannot reach. (Please make sure that you have some stopper to prevent the bottles from rolling off!) Using the physics of cool air sinks while hot air rises, this can possibly help to keep the wine cool and avoid too much temperature variation while it is being stored. However, the humidity is still a killer component should this be kept in a prolonged period (I must say not more than 2 weeks!)

When I first started enjoying the magical grape juice, I stored new and half finished bottles of wine in my refrigerator, and to a point that there is no space left for what it is really meant to keep - food. Finally, I decided to invest in wine coolers where I can safely keep my wine under a controlled environment and with little disturbance. Wine coolers come in different forms – standalone 30-200 bottle capacity in glass or solid door. Personally, I prefer the solid door version simply because it presents the least worries in terms of heat and light shielding. Wine coolers are affordable as most of them are now manufactured in China and Malaysia. One can get a good quality 30-bottle wine cooler starting at S$350. For someone who has a wine collection of more than 500 bottles, it is perhaps best to convert one of the rooms in the house into a walk-in wine cellar with air-conditioning and humidity control. Overall, there is no better way to store a wine than to cellar them properly.

By Cher Lim
Wine Treasures Pte Ltd
http://www.wine-treasures.com
Email: limce@singnet.com.sg

The science of wine glasses

Most consumers are overwhelmed by the large variety of wine glasses. Some manufacturers (Riedel, Spiegelau, Schott..) designed glassware for different wine style, naming after the wine grape variety. The standard tasting glass devised by the Institut National des Appellations d’Origine (INAO) has a height of 6 inches and holds 7.25 ounces of liquid. A slightly larger glass is also available that holds 10.5 ounces and is 6.875 inches tall. The glass has a tulip shape on a stem which enables the wine to be swirled easily around the bowl to encourage aeration of the wine. The design is such that it has an effective presentation to the eyes, the nose and the tongue of the person tasting the wine. In wine tasting, one looks for clarity, color intensity and its shades. The nose seeks the aroma, intensity, condition of the wine as one breathes in the bouquet. Finally, the tongue confirms the sweetness, acidity, tannin, body, intensity, flavor and length of the wine. All these act in concert to reach a conclusion on the quality of the wine, giving the person tasting the wine a complete picture of its grape varietal, production region and vintage.

Glasses that are designed for different wine style generally vary in the size and height of the bowl. What I have noticed is that the bowl size for wine style such as Pinot Noir or Nebbiolo tends to be bigger in diameter and tapers towards the mouth piece more than those designed for other grape varietals. I supposed this is because the Pinot Noir is more gently perfumed than most red grapes and often carries a nose of raspberries over a nice, sweet palate. The tapering angle is such that the person tasting the wine will enjoy the sweet entry of the liquid as the shaped guide the wine along the tip of the tongue (where the sweet senses are) through to the side and back of the throat. The fine tannins of this grape is easy on the palate and with the sweetness at the tip of the tongue, the positive characteristics of a pinot noir are most elaborated.

A champagne glass has an elongated bowl because it is fun to watch the bubbles in the wine rising towards the surface. Although a standard INAO glass may provide a better tasting experience in terms of capturing the aroma and bouquet of a good Champagne, part of the fun in drinking a wine is to observe and taste. As long as the glassware meets the functions of basic wine tasting, all variations that pleases the eyes and the “swirling” experience is a matter of choice to the consumers.

Cher Lim
Wine Treasures Pte Ltd
http://www.wine-treasures.com
Email: limce@singnet.com.sg