Let’s start small.
Plants contain an organic compound called phenol. It looks like this: C6H5OH. A group of phenols is a murder- just kidding- is a polyphenol. When phenols naturally group together as a polyphenol they create something called tannic acid. This acid is known for its ability to dye fabric and tan hides.
The term polyphenol does not have a universal definition, but it can be agreed that they are a natural and aromatic structure. While aromatic means one thing to a wine drinker, in chemistry it is referring to a molecular structure that is ring shaped and flat. These rings are very stable and do not break apart easily. Even those of us who live on the outskirts of chemistry can visualize how aromatic compounds could be strong enough to make a mark on anything it touches. Therefore, polyphenols end up playing a big part in the creation of a wine’s identity.
Tannins which come from tannic acid bind with any protein it meets. One of the results of this bondage is the sensation of astringency. This comes from the binding of polyphenols to the proteins in our saliva which then leads to a muscular contraction that may give a feeling of dryness in the mouth that makes you numb and pucker. Certain fruits cause this reaction all the time, and some only before they are ripe. In the natural world, tannins help protect fruit from being eaten before it can distribute seeds and regulate its growth. They also act as medicine against certain bacterias, and UV protection. In the domestic world, tannins are used to determine when it is time to harvest. A winemaker might test a grape by picking it and eating it or using a refractometer, which tests the sugar and alcohol levels of a grape still on the vine. If a winemaker is looking to create a more tannic drinking experience, they will harvest early.
Technically, tannins cannot be smelled or even tasted. They give us an experience. They are there and not there. Their physical reaction with our body is a bitter message from our (thankfully) still existing animal sense that we should not be imbibing in this nectar. However, we do, and we love it. We have grown to relish and celebrate the discomfort of astringency. It is our dance with the devil. It is throwing caution to the wind and yielding to the carnal instinct of pleasure being laced with pain (on a very very low level in this case). This month, as we indulge in some Say Tannic worship, we must also celebrate the duality of the tongue. Its ability to nurture and feed, as well as cut with words. It is the follower in the tango with tannins. Get ready to pucker up.
Wine tannins have five different sources: skins, stems, seeds, pulp, and oak/ additives. On top of that, each source produces a different type of tannin with different sizes, strengths, and bonding abilities. These different characteristics affect the amount of astringency you will encounter when drinking wine. If you were to consider each tannin source as an aspect of a wine’s personality, you can create quite a range of experiences by dialing up or down each source’s influence. Clark Smith, a consulting winemaker, writer, and educator based in Santa Rosa, California, offers this analogy to explain the complexity of tannins in wine: “Take the dizzying array of thousands of different phenolic compounds,” he writes in his book, Postmodern Winemaking. “Then start to take these monomeric [single] units together like Legos [forming tannins], and shortly you end up with many millions of combinations as unique as snowflakes.” (The Science of Tannins in Wine, Seven Fifty Daily) This can really shed some light on the work of the winemaker, when you meet a well balanced bottle. To start, let’s take a look at the tannins that come from the part of the grape that every bottle of wine has in common: the pulp.
While all plants contain phenols, wine grapes contain phenols that are either flavonoids or non- flavonoids. There are a number of elemental differences between these two types of phenols, but for our purposes, we will notice the visual difference. Flavonoids are made of a 2 phenol ring structure where non- flavonoids have only one. This physical structure shows us that the simpler structure of non- flavonoids will produce less tannins that will polymerize (link together with other polyphenols) more slowly than the sturdier two ring structure of flavonoids. The source of non- flavonoid phenols is primarily from grape pulp and oak barrels, which will have the biggest influence on white wines. Because white wine is made by crushing grapes and giving the juice no time to sit on the skins, white wine avoids flavonoid tannins from the skin, seeds, and stems of the grape. The non- flavonoid tannins that are left come from the grape pulp and oak barrel vessel and help with color stabilization and can impart different levels of astringency depending on make up of the specific varietal of grape, or the oak itself. Therefore, when drinking white wine, the tannins you are going to encounter are going to be experienced through the color and texture of the wine.
QUEEN OF THE SIERRA WHITE BLEND
USA, CALIFORNIA, SIERRA FOOTHILLS, CALAVERAS
Chardonnay, Verdelho, Muscat
Vineyards at 2000' ASL
Soils composed of schist over dolomite-rich limestone
All grapes are hand-harvested
Rested in neutral oak
Nothing was added to the must or the wine aside from a small amount of SO2.
The Queen of the Sierra white blend was aged in a neutral oak barrel for 18 months. Neutral oak is an oak barrel that has already aged another wine, or even a couple other wines. When using a new oak barrel, the flavors of oak and the tannins that come with it are imparted to wines somewhat quickly. After a few uses, the barrel becomes "neutral". This does not mean, however, that the barrel has no impact on the wine. In fact the opposite is true, a neutral barrel is a precious tool for the winemaker.
Matthew Rorick and the team at Forlorn Hope are crafting hand-harvested, foot-trodden, slow aged wines. They always use native yeast and add nothing to their wines except minimal SO2. They have 75 acres in Calaveras County in the Sierra Foothills at an elevation of 2000' ASL. This alpine climate allows for grapes to ripen more slowly, developing that perfect balance of acidity.
Neutral oak barrels, and the porosity of wood, can allow a wine to breathe while it is aging. This oxygenation allows the qualities of each grape in the blend to integrate more with each other. Forlorn Hope does not use any new oak on their wines, preferring the mellow freshness that comes from aging in a neutral oak barrel. While white grapes tend to have a lower amount of naturally occurring tannin, they do still have some. The use of neutral oak therefore allows us to feel the natural tannins from grape pulp more softly on the palate.
You may think of red wine to be more tannic. And Satanic! This is thanks to the flavonoid phenols found in the skins, seeds, and stems that sit on the juice after grapes are crushed. These three sources of flavonoids create tannins that grow and link together in small tight chains especially fast the younger they are. The process of making red wine allows for grape skins, seeds, and stems to sit with the juice for longer periods of time than a white wine or rosé, which in turn allow for more tannic acid to be added to the juice, giving more color and depth, depending on the grape and maker. If you can picture oak or pulp tannins experienced in wine to be like Swan Lake, then tannins from the rest of the grape (skins, stems, seeds) is The 1812 Overture.
Another interesting factor in flavonoid tannins from the skins, stems, and seeds of a grape is time. Understanding tannin production in grapes before veraison (ripeness) is quite simple. A grape grower or winemaker might use a refractometer to check the sugar levels of a grape and decide when it is time to harvest based on that number. However, once the grape has ripened, been crushed, and is fermenting, tracking tannins becomes much more complicated. This is because the polyphenols that create the tannic acid start polymerizing (binding together in a chain) and depolymerizing (unbinding) back and forth. By the time a wine is 3 years old the tannins have evolved and it is only possible to identify less than 50% of tannic activity.
This is all to help illustrate not only the mysterious underworld of tannins, but to also show how tannins change as wine ages. Typically, astringency levels will settle down the longer a wine has been aging. Polymerizing/ depolymerizing slows, chain making stops growing longer and starts becoming more complex resulting in a softer touch. Additionally, young tannins start out in a rod-like shape with lots of surface area to connect to salivary proteins creating the mouth puckering dryness sensation. As tannins age, they lose their tight form and start becoming more globular giving them less interaction with protein, also causing the same result of a less astringent impact. This is a concept we can relate to as we experience our own bodies and life force change with age.
To Note: Learning about tannins is complicated. It is filled with unknowns, misunderstandings, and rumors. It has a scientific element and an experiential element. There is a small group of scientists working to untangle the web of tannins post veraison, and we are grateful for their laser focus on a tiny but huge part of winemaking and drinking. This month’s Club Caravan is meant to be an intro to an intro of a much more involved topic. If you are interested in knowing more about our sources, please get in touch!
Blaufrankisch, St. Laurent, Zweigelt
6 Months in Stainless Steel
Small amount of SO2
Meinklang is a diverse farm nestled in the middle of a World Heritage Site of the National Park on the Neusiedlersee in Austria. This is just west of the Hungarian lowlands. This is a family run farm that utilizes a range of crops and farm animals as a way to increase biodiversity, create healthy soil, and therefore, vibrant fruit on the vines.
The Burgenland Red is a blend of three red varieties and is aged in stainless steel tanks. We chose this wine so you'd be able to notice the naturally occurring tannins present in grapes alone as stainless steel is a neutral vessel and imparts no flavor onto the wine itself. These are grapes that have tannins we'd define as "grippy", meaning that they make the tongue feel a bit sticky, but do not dry out your whole mouth. With the balance of acidity in this wine, the tannins fade into the juiciness of the wine.
Meinklang's choice to use stainless steel allows us to experience the natural personality of the grape and the influence of the land.. The tannins in Blaufrankisch have not always been an easy grape to ripen. It is in part due to climate change that these grapes can now ripen more fully. While the tannins present in this wine are not incredibly sharp or strong, their presence is what helps give this wine its peppery richness, and what allows us to enjoy the fresh fruit elements of strawberry, raspberry and cherry. Without a tannic backbone, the wine would just be juice.
Sagrantino: Umbria, Italy
Petite Sirah: Originally French, now largely found in California.
Cabernet Sauvignon: International
Petit Verdot: Bordeaux, France
Monastrell/ Mourvedre: Spain and France
Our aim is to give a glimpse into the many roles wine has played throughout history. All subjects mentioned deserve more attention and research and we encourage you to keep exploring. We are only here to pop the cork.
Many Thanks, Caravan Wine Shop
* All artwork by Lenora Howl