Why add oak to wine?

The Morewine catalog came in today's mail. I noted pages of oak products for adding to wine including oak tannin, chips, sticks, etc. Why add oak to wine? If the wine tastes good, why make it taste like a tree?

Oak adds a wonderful level of complexity to a wine. It really makes it taste complete, particularly for red wines. I always add some.

I recently have made two of the same inexpensive kits. One I followed the directions, the other I added 1 oz of oak after primary fermentation was complete.

Didn't tell the wife until she asked, but she thought the body of the second wine, with the oak added, was a little heavier or fuller. So I'd say addition of body as well as flavor and the added ability to age it longer are some benefits of adding oak.

Different goals can be met depending on when you add the oak. Plenty of info on this site about that.

Adding oak will increase the body of wine. Actually, we need tannin to increase the body, so in my opinion we could substitute oak with tannin powder to increase the body. cmiiw.

Some of what tastes good about wine is tannins.

Here's more info:
http://midwestwinepress.com/2013/07/07/tannin-additions-in-red-hybrids/

"Tannin is to red wine what acidity is to whites: a backbone. Without either, it is difficult to make a balanced wine. This is one of the first principles I learned about winemaking (from Wine for Dummies, believe or not.)

Tannins are such an integral part of dry red wines that the renowned French enologist, Emile Peynaud, included tannins as one leg of his three-part (tripartite) model for a balanced dry red wine – the other parts being acidity and alcohol. In the Midwest, the low tannin content of red hybrids is one of the major challenges facing winemakers who seek to craft a dry red wine aimed at consumers whose palates favor vinifera wines.

Briefly, wine tannins are derived from two different sources: fruit and oak. Fruit tannins can be found in the skin, seed, and stems (if whole cluster fermenting) of grape clusters and are referred to as condensed tannins or proanthocyanidins.

Oak tannins differ in chemical composition, and are referred to as hydrolysable tannins. Overall, tannins are responsible for astringency in wine, the tactile sensation that imparts structure, body and mouthfeel wine characteristics. Tannins also play a secondary role acting as lifeboats for color compounds (anthocyanins) to glom onto during the aging process – hence improving the color stability of wines. (A more comprehensive review of tannin nomenclature and general chemistry is beyond the scope of this column; consult any general Enology textbook for more information)."

And from Scott Labs:
http://www.scottlab.com/products-29.aspx

"Winemaking tannins come from a variety of sources. These include oak (both American and European, toasted and untoasted), chestnut, grapes (both skins and seeds), exotic woods (such as tara and quebracho) and gall nuts. Though all tannins provide some degree of anti-oxidative protection, each is also quite distinctive. The selection, processing and blending are all critical when developing commercial tannins which you might use in your wine.

The descriptors often used to characterize tannin types are inadequate to the task. Words suchas ellagic (meaning oak or chestnut wood) or proanthocyanidins (meaning from grapes and some exotic woods) are very broad. The producer of winemaking tannins needs to understand and to quantify the potential of specific raw materials and then to apply this knowledge. Tools such as GC/MS (gaschromatography/mass spectrometry), reverse phase HPLC (high performance liquid chromatography) and TLC (thin layer chromatography) analysis (silica/fluorescence; cellulose) are common in this process.

Raw materials need to be tasted in different concentrations in different wines. Even if laboratory tools are useful for understanding products, tastings remain the key. There is no substitute if we wish to understand issues such as mouthfeel, relative astringency and increasing roundness. In particular, the polysaccharides linked with tannins contribute to the global impact on the palate.

These are the elements that went into the development of the Scott’Tan product range. It was an elaborate program. We believe you will appreciate the results."

I have read a lot about "over-oaked" wine but nothing to describe what's so bad about it. Personally, I have never tasted an over-oaked wine as I am a big fan of oak. Has anyone ever tasted a commercial "over-oaked" wine and can you provide some details on what exactly that tastes like? I have my first kit wine in process, it's a WV Shiraz and I added some medium and dark oak in different amounts to two separate batches. For someone who likes oak, I'm worried that I won't taste the fault of over-oaking. So far I'm finding that it brought up a real buttery flavor to the smaller batch after a month, but I have since racked that batch off the oak.

I add oak to most of my reds. I like the complexity it adds. But if you don't like it don't add it. It's your wine, make what you like.

Thanks for all the insight. Guess I will need to obtain some oak next time I order from Morewine.