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by Gabe Jackson, Copyright by The Beverage People 2023
The ancient Latin proverb that “Fortune Favors the Bold” was probably not often applied in a winemaking context, but it always implied that action must be taken to achieve great results. To extract and retain the richest and boldest flavors possible from your grapes, this bias toward action will serve you well. The path of least resistance does not produce the wine with the most body and flavor. Be bold and your wines will too!
Before discussing the actions that lead to bold red wines, consider the components that define boldness in red wines. Tannins and polyphenols are the key. Additionally, fruitiness that remains intact and enjoyable adds “intangible” layers of joy for the senses.
Tannins are part of a larger group called Phenols or Polyphenols including tannins, anthocyanins, phenolic acids, phenolic aldehydes like vanillin, flavonoids, many more. Some tannins will be harsh and unpleasant on the palate, while others produce a soft, full and lush mouthfeel. Most of them add to the color of the wine. NOT ALL TANNINS ARE CREATED EQUAL. To produce a satisfyingly bold wine, you need to understand about polyphenol polymerization. More on this to come.
Maintaining the fruitiness of the grapes in the final wine requires the skill and care of the winemaker. Oxidation can quickly diminish the fruity aromas, and eventually flavors, of the wine. Storage conditions, storage temperatures, SO2 usage and management, and a generally high level of care in avoiding excessive oxidation of the wine will benefit the fruitiness of the final wine.
In grapes, most of the tannins can be found in the skin, seeds and stems. The tannins available in the seeds and stems are quite astringent and unpleasant. For this reason, most modern winemakers try to remove them as much as possible. Grape crushers are usually equipped with a de-stemmer device. The delestage technique, which involves tedious rack and return transfers during primary fermentation, is sometimes used to remove seeds from the fermentation as they settle to the bottom of the fermentor. Within the skins resides the favored tannins of the winemaker. Some of these skin tannins are polymerized (already bound in long chains) while others are monomers (not yet bonded). This polymer vs monomer topic is important because it has a direct impact on the mouthfeel of the tannins.
If the tannin is monomeric, it will have many reactive sites on the molecule and will react with the proteins in your saliva as you drink it resulting in pain rather than pleasure as you drink it. Have you ever had a Cabernet Sauvignon that hurt to drink? The reason it hurt is because too many of the tannins in the Cab remained as monomers and had not yet achieved their full potential as beloved polymers.
If the tannin is polymerized, it will have fewer reactive sites on the molecule and thus it will be less astringent to drink.
So, even if you are very successful at extracting primarily skin tannins from your grapes, with less extraction of stem and seed tannins, there is still work to be done to polymerize those monomeric tannins into a soft, full mouthfeel.
Firstly, be aware that tannins are more soluble in alcohol than in juice. Due to this, they tend to extract better in that later part of the sugar fermentation once much of the grape sugar has converted to ethanol. This is important to know because an important pre-requisite to binding the tannins is to first extract them into solution.
Tannins can bind with many other molecules. They can bind with other polyphenols, anthocyanin color compounds, proteins, oxygen, polysaccharides, and others. During the fermentation and skin extraction process, you can take actions that influence whether the tannins will bind with other molecules, and to which molecules they bind. Consider a few of the most important tannin-complexes (tannins bound with other molecules) that you can influence in the fermentation.
This is generally considered the most desired type of polymerization. Anthocyanins are color compounds and are part of the phenol family. When they bind with tannins, they lend their red color pigment to the wine while also softening the astringency of the tannins they bind to. But they are tricksters. They are highly unstable when un-bound and tend to precipitate. Furthermore, they are highly soluble in juice, therefore they tend to extract before the tannins do in the fermentor. Left to their own devices, they tend to bind the available proteins, which are available early in the fermentation, and precipitate right out of solution. If this happens, the tannins extracted later will be left with very few anthocyanin friends to play with.
One approach to avoid the loss of anthocyanin color compounds is to pro-actively remove the proteins by binding them with tannins. These tannins must be added by the winemaker and are called “sacrificial tannins”. When added during the initial skin punch-downs, these non-grape tannins will bind with proteins and precipitate, leaving more anthocyanins available to bind with the grape skin tannins at a later point in the fermentation.
Polysaccharides are complex, non-fermentable sugars which add mouthfeel and smoothness to the wine. When bound with tannins, they will soften and polymerize the tannins. They can also be added to the fermentor by the winemaker in the form of Opti-Red®, a yeast derived product that is rich in polysaccharides and very effective. Adding them during a punch-down in the later period of the fermentation, when tannins are being extracted by alcohol, will have a noteworthy effect.
As you know, daily punch downs are an important requirement in red wine fermentation. You’ve likely read that they should be performed 2-3 times per day during the sugar fermentation. But have you faithfully performed 3 punch-downs each day, honestly? Punch-down before breakfast…punch down after lunch…punch down before bed… who’s to know if you skip one or two?
Punch-downs, especially aggressive punch-downs, accelerate the maceration of the grapes and extraction of the tannins. This in turn accelerates the creation of tannin-anthocyanin complexes and other desirable complexes, thereby stabilizing the color, softening the mouthfeel, and improving the wine from the very beginning of its life. After pressing out the wine, you won’t have another chance like this to so easily improve the body and flavor.
Saignée (pronounced “sohn-yay”) Technique
The saignée (bleeding) technique is simple and straightforward. In order to achieve greater skin extraction, you drain off a portion of the juice, thereby increasing the skin to juice ratio. The huge bonus of this technique is that the extracted juice can be made into a second wine---Rosé! If the extraction is done before the juice becomes deeply colored, generally in the first 2-12 hours after crushing the grapes, then you can produce a small side batch of rosé with low color, as well as producing a large batch of red wine with greater skin concentration resulting in a red wine with more body and flavor.
It will be handy to have a special strainer in order to extract the juice. A China Cap Strainer can be plunged into the crushed grape must rather deeply, allowing the juice to fill the strainer from the outside. When the strainer has filled with juice, scoop out the juice with a cup, bowl or beaker. Continue this until it becomes difficult to extract any further juice from the must.
China Cap Strainer helps with extracting juice from crushed grape must.
As discussed above, the skin tannins and anthocyanins tend to extract into solution at different times during the primary fermentation---generally early on for the anthocyanins, and later for the tannins. An extremely effective way to ensure that they successfully form desirable complexes is to extend the time that the skins are in contact with the juice/wine. This is called extended maceration. While simple in theory, it turns out to be difficult in practice due to the equipment requirements. But I repeat---it is extremely effective.
The standard practice of primary fermentation for red wines is to press out the wine once the skins begin to sink and no longer form a perky cap on top of the wine. This is typically 7-10 days into the primary sugar fermentation. Once the cap falls, the wine is open and exposed to rapid oxidation exceeding any level that might be considered beneficial. So, most often, the wine is pressed off the skins and moved to storage vessels that are topped up and sealed with airlocks. But an opportunity to greatly improve the body and flavor of the wine is missed. For those who take the effort to seal the primary fermentation tank from excessive oxygen exposure, you can keep the skins in contact with the juice/wine for an additional 2-6 weeks, resulting in a significant increase in skin extraction and desirable polymerization.
Variable capacity stainless tanks are quite handy for this technique. The “floating lid” can be put in place once the skins sink, thereby sealing off the wine from excessive oxygen exposure. I use this equipment and technique myself. I recommend it! Expect some overflowing of the wine onto the top of the lid and be ready to remove it and clean up each day for the first week or so. It’s worth it.
Variable capacity stainless wine tanks can be used for extended maceration fermentation.
A less-common approach to speeding the skin extraction is pulverization of a small portion of the skins. This approach has been tried and recommended by a local winemaking consultant, Clark Smith. Using a hand-held stick blender, a small portion of the cap is blended for immediate and complete maceration of that portion. Now, proceed as usual in all other ways.
Maceration enzymes speed up the breakdown of the skins, and result in greater extraction from them as well as a significant improvement in pressing yield. They are cheap and very effective. The results are not subtle. You will notice the faster breakdown during your punch downs, and especially during pressing. Expect about 10-15% more wine coming out of the press and be ready for it with containers.
As noted earlier, sacrificial tannins can be added by the winemaker during early punch-downs to pro-actively bind proteins in an effort to remove them from the solution. This allows more of the desirable complexing of tannins and anthocyanins to take place. The products used are generally gall nut tannins (see FT Rouge Soft) or oak powder.
Opti-Red® is a unique yeast-derived product that has undergone a process to obtain a high level of polyphenol-reactive cell-wall polysaccharides. When added in the later part of sugar fermentation during punch-down, it will bind with available monomer tannins. This can be highly effective at softening the mouthfeel. Remember that the anthocyanins can be tricky to keep in solution and successfully bind with the monomer tannins. Opti-Red effectively offers a second chance, or backup plan, for the winemaker to polymerize those tannins in the fermentor.
Post-pressing, there is another option for adding polysaccharides to the wine---Gum Arabic. If you have already pressed your wine and wish to soften the tannic astringency, give it a try.
After pressing out the wine, toasted oak is the most commonly utilized source of added tannins. It adds wonderful flavor and extracts further tannins, adding to those from your grapes. Oak tannins tend to be a bit harsh when young, and highly oxygen reactive. This is good news for slowing down the effects of oxidation. But they also tend to need long, slow oxidation in order to soften the harshness of these type of tannins. This process is often called “micro oxidation”, and oak barrels are uniquely effective at performing it.
If oak flavor and aroma is your primary objective, a toasted oak powder called Tannin Riche provides instant results. It will impart the rich vanilla of a freshly toasted French oak barrel and generally brings smiles to winemakers faces. But it should not be counted on for the same improvement of body and mouthfeel that aging in a barrel provides.
Finally, yeast selection can have an effect on the tannin extraction and development of mouthfeel in a wine. An Australian Wine Institute study of 11 yeast strains used in Cabernet Sauvignon fermentation found that yeast selection alone can account for up to a 33% difference in tannin concentration and differences in wine color. When reading about a yeast, you will notice that some will have descriptions such as “known to enhance mouthfeel”, or “helps with color stability”. These are good indicators that the yeast will play a part in producing more of the desirable complexes discussed above. Additionally, some yeasts will produce more glycerol than others, which adds to the mouthfeel and perceived sweetness as well.
If one were to deploy every technique and product discussed above, I doubt that the results would be 100% desirable. Over-extraction and excessive intensity are a possibility. Each and every technique will produce identifiable results, but more is not always better. The level of intensity and boldness you desire will be different than the next wine drinker.
To help you get a sense of the intensity impact that each technique may have on the boldness and flavor of the wine, I would suggest the following as a summary of the discussed techniques, listed in order from the technique I believe may have the most effect, down to that technique which may have the least effect. This is far from a scientific list. I just hope it may help you select a suite of techniques and products that will allow you to produce the red wines you will love to drink!