Cellar Cat Chat- Oak Barrels

Hi! Po’Boy Fowler back in my favorite spot in the cellar: curled up on top of the Sauvignon Blanc barrels. Why is this my favorite spot? Because we age Slouch Hat’s Sauvignon Blanc in 500-liter French barrels called puncheons. These are significantly larger than your typical barrel, so I can really stretch out and nap. Slouch Hat’s GSM is aged in 288-liter Burgundy barrels, which is one of the two standard sizes but too small for me. Other than impacting my nap time, why do barrels matter?

Oak barrels were first introduced into winemaking during the Roman Empire. This was mostly out of convenience since oak forest covered a majority of Europe at the time. Oak is also leakproof and strong, yet malleable enough to be made into barrels, so it is perfect for storage and transportation. As a bonus, winemakers and merchants realized that storing wine in oak barrels made the wine more pleasant – the big body reds became softer and more complex. Two millennia later we still age our wine in oak barrels. Do as the Romans do, right?

Today we have a much better understanding of why oak is perfect for winemaking. Not only is it abundant; strong, yet malleable; and leakproof, but it is also porous to a perfect degree. Over the course of a year a 225-liter barrique barrel (the other standard-sized barrel) will lose roughly 5 gallons of wine – about 24 bottles. That’s a lot of money literally evaporating into the air. So, why is losing wine good? Oxygen will slowly seep through the porous oak to replace the lost wine and softens the tannins. This is similar to opening a bottle of a young Slouch Hat GSM and swirling it around in a glass or pouring it into a decanter to aerate it. Suddenly, softer.

We now also better understand how oak is able to give wine more depth. Oak imparts several complex chemical compounds into wine. The most noticeable is polyphenol compounds. Have you ever tried a wine and picked up flavors or aromas of vanilla, coconut, cedar, or baking spices? Those come from the oak aging. Another polyphenol is tannin. Red wine already has tannins due to fermenting in contact with the grape skin, but oak can add more. However, this can be prevented through the exposure to oxygen and the toast level of the barrel.

Barrels are toasted? Oh yeah, like all things in wine we take what could be a relatively simple concept and make it entirely too complex. How else would a marketing department distinguish their brand from the 15,000+ other brands? All kidding aside, the toast level matters. When oak is made into barrels it must be heated over a fire to be bent into the right shape. The heat chars the oak and different heat levels char the oak more or less – this is the toast level. The higher the toast level the less contact the wine has with the oak cells that impart the oak flavors, aromas, and tannins. Instead, you receive flavors and aromas from the char – caramel, cloves, cinnamon, smoke, or coffee. The flavors and aromas you experience depend heavily on the oak’s source.

Hold up. Wait a minute. Put a little oak in it. Where the oak tree comes from matters? This is wine, so of course! Naturally, the French claim to have the best oak trees. They even have different appellations for their oak forests like the different appellations of vineyards. However, the same two species of White Oak that grow in France also grow very well in Eastern Europe, especially Hungary. (There was a bit of a scandal when it was discovered that French winemakers were secretly importing Hungarian oak barrels to save money, but that’s a story for another time). These oak barrels provide more subtle oak flavors but also provide more tannins and are more porous. There is a third species of White Oak that can also be made into barrels, and it grows in America. Specifically, it grows in states that touch the western edge of the Mississippi River from Arkansas to Minnesota plus Wisconsin. These barrels are much heavier, denser, and less porous, so they impart more flavors and aromas – such as vanilla and coconut – and are less tannic. Of course, the degree to which an oak barrel impacts the wine is directly correlated to whether it is a new or used barrel.

Yay, more factors to consider! This one is straightforward, though. A new barrel will naturally impart significantly more oak or toast flavors and aroma on the wine. A used barrel will impart less of those flavors and aromas. After about four uses a barrel is considered neutral and it imparts very little, if any, of those flavors or aromas on the wine. Therefore, the porousness – oxygen exposure – is what matters most at that point.

So, why did Slouch Hat Wines choose to age Sauvignon Blanc in neutral French oak puncheons and the GSM in neutral French oak Burgundy barrels? Since both barrel types are French and neutral, it’s all about the surface area to volume ratio. The more wine that can touch the barrel the more impact the oak will have on the wine and vice versa. Therefore, a Burgundy barrel that holds 228 liters of wine impacts the wine much more than a puncheon that holds 500 liters of wine. To put it simply: size matters.

That being said, these barrels are neutral, so the impact of the oak is less significant. This is especially important for Slouch Hat Sauvignon Blanc. We do not want oak flavors or aromas on the Sauvignon Blanc. We do want oxygen exposure, though, to soften the acidity and make the wine taste more rounded without sacrificing the beautiful tropical fruit and citrus notes of the wine.

Unlike the Sauvignon Blanc, Slouch Hat GSM does need some oak exposure to give it a touch more depth in flavor and aroma. More importantly, it needs the oxygen exposure to soften the tannins of the Mourvèdre and help the wines seamlessly blend into a wine that is similar to the oak barrel it comes out of – strong, but malleable on the palate. The oak imparts notes of baking spice but allows the Syrah to hold onto its blue fruit and spice flavors and blend beautifully with the red berry aromas of the Grenache and the softened tannins of the Mourvèdre.

There are numerous factors from vineyard management to winemaking decisions that go into making a bottle of wine. Ultimately, the barrel decision is as important and as complicated as the decisions on fruit and vineyard selection. Choose wisely.

Cheers!

Po’Boy Fowler

Chief Field Correspondent

Slouch Hat Wines