Fermentation Vessels Can Affect the Flavors of a Wine

In a recent blog, I listed some of the many factors that can affect a wine’s flavors. One of the factors is the type of vessel chosen by the winemaker to ferment the wine. So, let’s take a closer look.

The three most common fermentation vessels are made of either oak, stainless steel or concrete. Each of these can affect the flavor of the wine due to the degree to which the wine is exposed to oxygen.

Fermentation in Oak 
Oak fermentation barrels allow for the gradual influx of oxygen which helps to softened tannins and acid while developing a ‘rounder’ more balanced wine. Oak itself also imparts flavors. French oak is known to yield more subtle flavors like clove and spice to a wine while creating a silkier, smoother mouthfeel, while American oak typically imparts aromas of vanilla and coconut. And, the degree to which these flavors are imparted varies by the level of ‘toast’ created on the barrel during its production. So, for instance, a barrel with a ‘medium’ toast will impart less flavors than a barrel with a heavy toast. Finally, once an oak barrel has been used three to four times, the majority of the flavors have been extracted and it becomes a ‘neutral’ barrel that imparts little to no flavors.

Fermentation in Stainless Steel

Unlike oak, stainless steel fermentation vessels can be tightly sealed so as to allow little to no oxygen exposure of the wine during the fermentation process. And, a winemaker may fill the top of the tank (the headspace) with inert gas to drive out all of the oxygen. This makes for brighter, fresher fruit-forward wines. The stainless steel imparts no flavor characteristics to the wine. Stainless steel tanks are also used because they offer optimal refrigeration capabilities when a winemaker wants to cold-ferment the wine.

Fermentation in Concrete

Concrete-type vessels have been used to ferment wine for as long as wine has been made. Concrete tanks can be open for oxygen exposure, or sealed like stainless steel to avoid oxygen. The concrete itself is quite neutral so it doesn’t impart significant flavors like oak, but it can add mineral-like flavors to the wine.

How Fermentation and Aging Affect a Wine's Aroma

Last time we looked specifically at how oak affects the flavor of wine. There we learned that oak can be used in the fermentation process and/or the aging process to add various flavors to the wine. But before you take a first sip of wine, swirl your wine in your glass and then stick your nose into the top of the glass and experience all the wonderful aromas that the wine has to offer.

First and foremost, a wine’s aroma is based on the grape that is used in the wine. So, fruity aromas are those that are up-front. In white wines these aromas can include those of tropical fruits, melons, and citrus. In red wines you’ll find red fruit, black fruit and dried fruit aromas. So, these set the foundation for a wine’s aroma.

Now, let’s take a look at how the fermentation and aging process affect a wine’s aroma. First, fermentation - the process that turns the grape’s natural sugars to alcohol. And, the key ingredient in fermentation is yeast. Therefore, it’s not surprising that the yeast is a factor in a wine’s aroma. While the yeast doesn’t play a major role in a wine’s aroma, it can give a wine hints of fresh baked bread, butter, cream and cheese.

Then there’s the aging process. And, here aging in oak can yield a variety of aromas, some directly from the wood and others from the small amount of oxygen a wooden barrel allows inside. Depending on type of oak and how the barrel is toasted, it can lead to sweet aromas that including vanilla, caramel, brown sugar and butterscotch. The introduction of oxygen in the barrel can lead to nutty aromas. And, a heavily toasted oak barrel can even introduce aromas of smoke, tobacco, cigar and dried leaves.

So, don’t forget ‘smell’ as part of the five-Ss in wine tasting. Try it with your next glass of wine and see how many aromas you can pick out. Cheers!

Ever Wonder How Oak Affects the Flavor of Wine?

Oak has been used for thousands of years as a wine vessel. Going back to Roman times, it was an inexpensive and durable container for transporting wines over land and by sea. And, today, oak remains and important wine vessel.

Oak barrels are sometimes used during a wine’s fermentation process and regularly during the wine’s aging process. Both of these uses of oak imparts flavors to the final product.

The two most dominate types of oak used in winemaking come from France and the United States. Each adds its own unique flavors. French oak is known for adding nutty and smoky flavors. American oak’s dominate flavors are vanilla and coconut.

The flavors from oak are also enhanced by the “toasting” process in which the open-ended barrel is placed over a flame such that the interior of the barrel is heated to the point of either a light roasting of the wood or a complete charring of the wood. Winemakers order their oak barrels to be either light, medium or heavy “toast” in order to get just the right flavors for their wines.

Another factor affecting the flavors from an oak barrel is its age. When a barrel is new, it will impart more and stronger flavors into a wine. But, an older barrel that has been used two or three times may be referred to as “neutral” but will still add texture to a wine while preserving the fruit flavors, and yield more subtle flavors. Use of a combination of both new and older “neutral” barrels is also very common when a wine maker wants to ‘dial in’ a specific set of flavors.

And, while oak’s use in the making of red wine is common, its use in the making of white wine is less common. The most notable use of oak in the making of white wine is in the production of Chardonnay, especially California Chardonnay. A heavily oaked Chardonnay will take on buttery flavors, like popcorn and toffee. In fact, the connection between oak and Chardonnay is such that oak flavors are often used as a way of blindly identifying the grape itself.

Oak barrels also affect flavors in wine due to the fact that it is porous to oxygen. Oak allows oxygen to very slowly enter the barrel which, over time, results in making a wine taste smoother and less astringent.

Finally, winemakers must decide whether to ferment and/or age their wines in oak. Fermentation and aging in oak barrels yields greater integration of flavors than by doing fermentation in steel tanks and then aging the wine in oak barrels.

So, there’s a little bit about oak and how it flavors your wines. Cheers!

Behind the Cork™ - Phantom Red Blend by Bogle

2015 Phantom Red Blend by Bogle ($25)

The Phantom is back! Last week’s Behind the Cork™ feature was the Phantom Chardonnay that was so good I went out and bought another bottle. This week feature is the Phantom Red Blend by Bogle.

This Phantom Red Blend is comprised of 44% Petite Sirah, 44% Zinfandel, 10% Merlot and 2% Cabernet Sauvignon. It spent 24 months in 1 & 2 year-old American and French Oak.

On the nose you know you are going to get richness, dark fruit, some earthiness and a healthy dose of oak.

And that oak comes right through. Along with the richness of the Petite Sirah, and the jammy Zinfandel, you get wonderful chocolate and vanilla tones from the oak that are followed up with a low tannin, smooth and lingering finish.

I’ve enjoyed Bogle wines for years but this offering from their Phantom label, along with their Phantom Chardonnay, really step it up a few notches.

And, you can bet I’ll be out soon looking for more of this Phantom Red Blend by Bogle! Cheers!

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Disclosure of Wine Sample Submission: I received this wine at no cost for review. The opinions expressed are entirely my own.

Sample Provided by Bogle Vineyards

Behind the Cork™ - Thomas Allen Generations

2016 Thomas Allen Generations Red Blend ($7)

This was a new one to me. I’d previously tried the Thomas Allen Cabernet Sauvignon, but wasn’t aware of their red blend.

Thomas Allen is owned and operated by third generation wine grape growers, Thomas Michael Stokes and Allen Lombardi, who grown their grapes in Lodi, CA.

This Thomas Allen Generations is a blend of Syrah, Petite Sirah, and Tannat that makes for a very full-bodied wine. Bright fruit aromas and a hint of pepper hit your nose while its flavors include dark fruits, plum and sour cherry. The oak also gives this red blend nice vanilla and mocha flavors.

It’s an easy one on the palette, low tannin and a light finish.

This is yet another wine that fits the Behind the Cork™ mold being a great value that you should be able to easily find. Enjoy this one. Cheers!