Home Winemaking – ‘O’ for Oak and Oxidation #AtoZChallenge

Welcome to the World of Winemaking! I’m having fun alphabetizing the home winemaking process – you can find the links to the other letters at the end of this post.

Today’s letter is “O”, so we’ll talk about Oak and Oxidation – excitement abounds, I know!

Oak – The most commonly used wood source for fermentation vessel and barrel aging. Oak influence can also be imparted to a wine by the used of oak chips or staves.

Oak influences wine by color – the influence it has is more noticeable in white wines – for instance, a white wine which has been “oaked” takes on a more golden hue. This is not only from the oak itself but from the controlled oxidation of the wine as well. For red wines, it is less noticeable, but oak has a way of stabilizing the color of red wine. This enables the wine to retain its color even with age once it is in the bottle.

Toasted oak barrels also influence the aromatics of wine – a barrel can be lightly toasted, heavily toasted and many levels in-between. Sometimes the barrels are also toasted on the top and bottom. All of these aspects give the wine particular aromatics which affects the scents a wine taster experiences upon each visit to the rim of their glass.

And of course oak has influence on the body/texture of wine – regardless of the oak utilized, it will impart many characteristics influencing the mouthfeel, texture and body of a wine. The most well-known element is tannin. Tannin is the texture you note when drinking a cup of unsweetened tea (no cream or milk). The tea takes on a bitter taste and the texture dries one’s mouth.

Tannins also come from the wine grapes as well, but are only really noticeable in reds. This is because red wine is made in contact with the skins of the grapes (which also introduce characteristics: color, aroma and texture/body). The more tannin and other characteristics elaborated in the wine, the more body/texture it will have.

Oak is used more for red wines vs. white wines – why? Because white wines are not fermented with their skin, rather the grapes are pressed prior to fermentation and the juice alone is fermented. Thus, there will be lesser tannin to be imparted into the wine from the skins. Oak is also rarely used for white wines because of their delicate nature. Oak, if not used with discretion, can take over the delicate characteristics of a white wine, in its aromatic notes, flavor and texture.

Moving on to Oxidation…

What’s the biggest, baddest, wine flaw of them all? Say hello to oxidation, your wine’s worst nightmare. But isn’t oxygen good for wine, you ask? How can something we’ve been taught is so good for wine be the contributor to the biggest wine flaw of them all? Like anything else, too much of a good thing can lead to a demise – yes, even for your favorite bottle. 

It’s true – wine does need oxygen. The whole “let the wine breathe” phrase isn’t total nonsense; introducing oxygen to a newly opened bottle of wine or a freshly poured glass (hence, why we decant and swirl) is entirely beneficial. The moment that wine encounters oxygen, it begins to break down, or “open up,” as many people say.

Oxygen allows the aromas in wine to become more present, making it easier to identify what exactly you’re smelling. Introduction of oxygen also softens the mouthfeel of wine; this is due to the breaking down of tannins, the cause of that harsh, dry sensation you may feel along your cheeks and tongue. I refer to that as a ‘fuzzy tongue’, and don’t particularly care for those wines. 

However, too much oxygen can lead to oxidation, the degradation of wine due to an abundance of oxygen. This can happen during the actual winemaking process or even after the wine has been bottled.

Basically, all oxygen needs is a simple catalyst for the reaction to occur. When oxidation takes place, the wine’s pigmentation will decrease and loss of aromas and flavors will occur.

Think of an apple that’s been sliced and left out too long; the abundance of oxygen causes the flesh to brown, the aromas to dissipate and the flavors to disappear. 

Same thing goes for oxidation in wine. You can determine if your wine is oxidized by looking to see if the juice is slightly brown in color, with zero aromas of fruit and a lackluster palate, potentially displaying notes of vinegar, those are signs of a fully oxidized wine. Unfortunately, oxidation cannot be reversed and the wine will be ruined.

Winemaking is so much fun – at least for me – and am tickled every time I give the wine I make as gifts to friends and family who love drinking it as much as I love making it. While we go through this alphabetical series on winemaking, if you have any burning questions, be sure to ask them in the comments below, and I’ll reply there – and maybe even highlight your specific question(s) in a future post!

Thanks for joining me in this fun adventure!

Here are the links going backwards for your convenience, in case you missed any:

A for Aromas, Acidity and Appearance
B for Barrels, Bottles and Blackberry Wine
C for Color, Clarity, Carboys and Cherry Wine
D for Decanting and Decanters
E for Equipment
F for Fermentation
G for Glass and Grape
H for Harvest
I for Infusion
J for Jeroboam and Jug
K for Kabinett
L for Leaf, Label and Lees
M for Merlot, Muscat and Must
N – the Nose has it!