Olde Riverside Winery Inc

Proud member of the RJS Craft Winemaking Academy

Why Does a Wine Need Decanting?


Young wines can benefit greatly from decanting. The action of decanting itself, and the large surface area in contact with the air in the decanter, alters the wine, softening its youthful bite and encouraging the development of the more complex aromas that normally develop with years in the bottle.

On the other hand, some wines that are high in tartaric acid (a sign of a good quality grape) may produce a fall out known as tartrate crystals or 'wine diamonds'. Although these wine diamonds do not in any way alter the taste of the wines, they can be displeasing to the eye and in this case would deserve decanting to separate the wine from the diamonds.



Decanting Wine: How to do it

If you are decanting a young wine simply to aerate and liven it up a little, simply pour the wine into any suitable decanter/carafe with minimal agitation.

If you are decanting a wine in order to remove wine diamonds from it, following this procedure may be helpful:

If there is a considerable amount of wine diamonds it's advisable to stand the bottle upright for a day or so prior to decanting, allowing the diamonds to fall to the bottom of the bottle.
Once settled to the bottom, remove the entire shrink cap from around the neck of the bottle. It's important to remove the whole cap, and not just the top, as you need to have a clear view into the neck of the bottle so that you can observe the wine coming through the neck.
Hold the decanter in one hand and the bottle in the other, and with a smooth and steady action, pour the wine into the decanter. Don't rush when decanting, use a gentle, steady movement to avoid disturbing the diamonds in the wine.
When you see the diamonds moving into the neck of the bottle that is when you stop pouring.
It's now when you have a clear wine for serving from your decanter.Type your paragraph here.



What are wine diamonds?

Wine diamonds are crystals of potassium bitartrate.  They are a naturally occurring byproduct of fermentation.  They can have the appearance of loose sugar crystals or can form larger clumps of crystals.


How are wine diamonds formed?

As a wine ferments the alcohol level increases.  The higher the alcohol level the less likely a wine is able to keep tartaric acid in solution.  When a wine is chilled, the ability to keep tartaric acid in solution further decreases.  These two factors combined can lead to crystals forming in the wine as the tartaric acid falls out of solution.  Once crystals begin to form there is a snowball effect where the presence of crystals facilitate the formation of more tartrate crystals.


How will wine diamonds affect my wine?

Potassium bitartrate crystals have no taste or aroma.  They do not affect the profile of the wine or how it is perceived.  The drop out of tartaric acid also has a negligible effect on the overall acid level of the wine.  Most people carefully decant wines with diamonds before consuming so that the wine retains the intended aesthetic value.


I heard that wine diamonds indicate quality juice.  Is this true?

Grape juice that contains a high level of tartaric acid generally comes from ripe grapes that are well balanced in their analytical specifications.  The taste and aroma of the finished product is always a better indicator of the quality of the juice.


Why do some wines have wine diamonds and not others?

Whether your wine will produce wine diamonds is largely based on the initial tartaric acid concentration of the grapes.  White grapes from cooler climates tend to have more tartaric acid although warm climate red grapes could conceivably drop out wine diamonds when fermented.  This is more likely in red wines that have a very high alcohol percentage.


How do I avoid wine diamonds?

The simplest way to avoid wine diamonds is to not store wines in the fridge.  The cold temperatures in the refrigerator will accelerate wine diamond formation.  Therefore, only chill bottles in the fridge prior to drinking. 
Some winemakers have the capability to cold stabilize their wines.  Before bottling, the bulk wine is placed in a cooler for two weeks.  This is normally enough time to remove any wine diamonds that might have formed in the bottle. 


Why don’t commercial wines I purchase have this problem?

Commercial wineries often cold stabilize their wines prior to bottling.  This is especially true for white wines.  If they did not cold stabilize their wine, you would see wine diamonds in their products as well.here.