The French have imposed upon their wine country a system of calling out quality wine regions. It is quite elaborate, defining levels of wonderfulness that impose progressively stricter rules at the higher levels of elegance. The French have even taken these practices and imposed them upon other wine growing countries that they have occupied or have had as colonies. But the real genius of this began on the 10th of September in 1756, in Portugal. Shocked?
The British had taken up residency in lodges in the city of Vila Nova de Gaia, at the mouth of the Douro River and the Atlantic Ocean. Trade between the Portuguese and the Brits had been established in 1703, with the signing of the Methuen Treaty, wherein Portugal enjoyed lower duty rates, and in turn, the Brits’ demand for Port wine increased. To keep up with the rate of demand, additions such as elderberry juice was added to the port to stretch it out. This resulted in a lower quality, for which, eventually, demands slumped and oversupplies sat dockside. The Marques of Pombal—the prime minister at the time—created the Companhia Geral da Agricultura das Vinhas do Alto Douro to oversee quality control, which led to the 1756 new regulations.
So, what then adds to the quality when crafting Port wines? It can be argued that quality wine starts in the vineyard. Part of the Companhia’s role was to survey the Douro Valley’s vineyards and score them for quality levels. The score dictates the volume of grapes to be harvested for the specific level quality to be produced. First to be reviewed was the direction of the schist slates. The more vertical the schist slates are, the higher the chance the roots will be able to penetrate, crumble the slate, and find water. The vertical direction was caused by ancient tectonic movements that uplift the rocks. Other components of the score include elevation, slope angle, and which way the slope faces.
There are several different kinds of port wine out there: ruby and tawny are the most frequently purchased, and lay at the lower end of quality. Higher-level quality options include Late-Bottle Vintage, Vintage, Crusted, Single Quinta, 10 year, 20 year, 30 year, 40 year, and very old port. (Rosé and White ports also exist but that is a different blog!) Let us just note here that there are specific production procedures to accomplish for each of these styles.
Each grape variety has, of course, specific characteristics to benefit the specific styles. It is then necessary to have different blends to produce the different styles. If the goal is a lower-quality ruby port, then the end product will have soft easy tannins, bright primary flavors like red cherries, and it will exhibit a bright ruby color. To get to the ruby style, the winemaker may choose Tourigia National, and Touriga Franca, which seem to be the bases for almost all ports. Both of these grapes add flavor, aromas, and color stability. Soft pressing allows the juice to be set free, the skin to tear along cell walls, and the seeds not to be crushed, for the goal of soft tannins. The goal of ruby port is to have that bright ruby color and two actions are needed here for this. First is two to three days of allowing the skins to bleed off the color into the juice. Still to this day, foot power is really the most effective, but not necessarily the most cost-effective for lower end ruby ports. The second is a short aging in oak barrels, long enough to allow the tannins to integrate and for malolactic fermentation to make the wine rounder, but not so long that too much oxidation takes place, which fades the color.
Maturing of wines is done in a solera system, which is used for both port and sherry wines. Fractions of young wine are progressively added to older and older barrels. The oldest of wines are bottles to make room in the barrels for the next oldest wine to be blended in. Because of all this blending, the resulting wine has been homogenized, so that year after year, the wines will be the same style, same aromas, flavors, and characteristics. Ruby ports are generally in this system between five and seven years, depending on the winery.
If the goal is a tawny port, the blend may also include Tinta Barroca, which adds earthy notes, and a color that fades quickly. Lower-quality tawny ports need to have less skin contact, to produce a paler wine that then fades to the tawny color in that same amount of time—five to seven years. It also is aged and blended in its solera system. The goal for tawny wine flavors is to lose its fresh fruit flavors that are replaced with baking spices and nutty flavors.
Late-bottle Vintages, Vintage ports, Crusted, and Single Quinta ports start out closer to the ruby style, but are aged much longer than the generic ruby port. This means that the wines need to hold their ruby color without fading. This is accomplished by first choosing a blend of grapes that add deep, sustaining color. Then proceed with an aggressive, yet gentle, two to three days of maceration of skins in the juice, a quick fermentation, light aging in barrels to polymerize (integrate) the tannins, then off to bottling. The key here is that the aging for these wines happens protected from oxygen, protected from fading color, in a bottle. Most of these wines will be fine and filtered. The Crusted and Single Quinta will not, as it is thought the sediment adds to the body, flavors, and texture of the wine.
The 10 year, 20 year, 30 year, 40 year, and very old ports start out closer to the tawny port style. The difference is that the wines are held for a great length of time in the solera system where the aging is oxidative. Meaning the blend of wines must start out with deep color and tannins that will fade at a slow pace over the targeted year points. Varieties such as Tinta Cão, Tinta Roria (tempranillo), and Sousão would be add to the Touriga National and Touriga Franca for these styles. The resulting wines—say the 10 year tawny port—will have droplets of 10 year, but may have droplets mingled in that are 5 and 20 years old too. The Companhia sends out judges to taste and inspect the solera system, to qualify the wine to have 10 year tawny characteristics before the wine is released for sale.
Port wines are unique from other fortified wines in the usage of a fortifying spirt. For most fortified wines the spirt used will be between 95 and 96 percent ABV so that the wines will be raised to fortified ABV rates between 15 and 18.5 percent ABV with as little as possible, so as to not to dilute the wines. Port wines use a spirt of 77 percent ABV which then needs a larger quantity of the spirt to reach fortified levels. This means the quality and characteristics of the spirt will affect the quality and characteristics of the wine.
The takeaway then? Grape variety, vineyard location, skin contact, length of maturing, vessel for maturing, fining and filtering, and blending choices all add to the style, quality, and price tag of the finished port wine.