April 25, 2011

Skin Contact

    Time that grape must spends on skins and solids during maceration. For red wines, ranges from several days to several weeks. Rosé wines spend a day or two on the skins. White wines do not normally spend time on the skins, although some winemakers will allow limited skin contact. *
To produce wine is a fairly simple thing:  toss together some fruit juice and some yeast and wait. Grapes are a very good way to start because their juice contains all the right ingredients, and their skins even have a layer of ready-to-use yeast. OK, that gets us wine, but how do you create a quality wine, a distinctive wine, a wine for the ages?
A cluster of grapes consists of stems, pulp, juice, skins, and seeds. White wines are made from just the juice. But red wines need more stuff than pulp and juice alone can deliver. Red wines need, first of all, colour, and that comes from the skins. Red wines also need tannin, and that too comes from the skins (some tannin also comes from the stems and seeds). So, to make a suitable red wine, we need to leave the juice  –  the must  –  in contact with the skins. And since nothing is simple when it comes to wine (itself a simple beverage) the decisions surrounding skin contact are many.
A white wine may have some skin contact, usually measured in hours. This can give the wine a subtle boost in terms of colour and aromatics. Too much skin contact, though, can extract skin tannin and that’s something we don’t want in a white wine, so the winemaker will press the juice immediately or after brief skin contact.
Red wines can macerate in contact with the skins for hours, days and even weeks, depending on the goals of the winemaker. One way to produce rosé wines, for example, is to allow a day or so of skin contact. Sometimes enough colour can be extracted simply by pressing the grapes very slowly for hours of controlled skin contact  for a wee bit  of colour and not much tannin.
Now let’s follow a batch of red wine. When we say skins we’re also talking about stems and seeds … it’s a package deal. We can use a mechanical destemmer to remove as much wood as possible, but most winemakers will leave in some of the stems. Stem tannin can improve a wine’s structure, and will also enhance its ageing ability. Seeds will quickly drop to the bottom of the fermentation tank where they don’t have much effect. The rest of the mass – the skin, stems and remaining pulp – has to be controlled.  Fermentation produces a lot of carbon dioxide that rises to the surface, carrying the mass of stems and skins – the ‘cap’ – with it. To keep the wine in contact with the skins, and to prevent decay setting in, the cap must be pushed back down, up to several times a day.
The winemaker will assess the wine’s progress daily, and eventually gives the order to ‘rack’ the wine off of the skins. That order can come after a few days, when a lighter, less tannic wine is the objective, or maceration can continue. After about 10 days, most of the goodness has been extracted, and this is when most wines will be racked. Some winemakers will allow the process to continue well past that mark. Wine can stay on the skins for as long as a month. An interesting thing happens in that case. Instead of extracting more and more tannin from the skins and stems, the tannins can, in fact, soften. But this is ‘white knuckle’ winemaking, and is usually attempted only by the most intrepid winemakers.

April 19, 2011

Reserve *
    An unregulated New World term that suggests a higher quality wine that has been “reserved” from the rest of that year’s harvest, but can just as easily be meaningless.

Not much in the way of Q words to choose from, so let’s move right to the R's. The notion of a ‘reserve’ wine is that it has been set aside as being the best of that year’s batch. Occasionally the reserve wine is created by design, with the winemaker taking extra care every step of the way on that wine, whereas the remainder of the lot is handled in a more everyday fashion.

After the wine has aged in barrels for the allotted time, it will all be blended together in one large vat to create the cuvée. While in the course of sampling the barrels, the winemaker will also be looking for exceptional barrels. These would then be set aside to go into the reserve wine. In Old World wine regions, the practice is common-place, and the terms Reserve, Reserva, and Riserva are all regulated. You cannot use these terms on the labels if your wines don’t make the grade. Nor can you call ALL your wine reserve. It must have been reserved from something.

Not so in the New World. Most of these wine regions have yet to put in place any kind of appellation systems, let alone quality tiers. With little in the way of labelling regulations, anyone can put practically anything on a wine bottle. It’s not unusual to see bottles labelled “barrel reserve” or “cellar reserve” that have seen neither a barrel nor an actual cellar. There are even wineries that label all of their wines as reserve. Makes you wonder what the non-reserve stuff must have been like.

April 11, 2011

The bug that ate its way through Europe

Phylloxera Vastatrix

    A microscopic North American aphid that feeds on the roots and leaves of grapevines. Responsible for destroying most of Europe’s vineyards from about 1860-1900. North American vines and hybrids are mostly immune and are used as rootstock for virtually all grapevines today.  
Before the days of quarantines and importation standards, humans trafficked freely in plants and animals, thereby transplanting a lot of invasive species that wrought destruction instead of the hoped for boon. When explorers touched down in the New World, they notice the grapes right away. Soon after came wine made from North America grapes. And what retched wine it was. So why not plant a bunch of European grapevines in Canada and the US. The foreign grapes flourished in this hospitable climate, but after a few years they all sickened and died, and for no known reason. Well, if that experiment wouldn’t work, maybe taking the prolific native vines back to Europe would bestow some of the classic European flavour to the wines. Worse than not a very good idea, the North American vines that were planted in France in the late 1850s and early 1860s carried an alien -- an alien that loved these defenseless grapevines. It took barely 20 years for the phylloxera aphid to destroy some 6 million acres of vineyards in France, Spain, Italy, and elsewhere. 

North American vines had managed to co-exist semi-peacefully with the bug (it infects mainly the leaves), but the European vinifera grapevines had no such resistance. Many treatments were tried -- some of them irrational and even shocking -- with no success. Because North American vines were holding their own, vinticulturalist began to experiment with cross breeding. That resulted in a large number of “French hybrid” grapes, many of which are still in production in marginal wine-growing areas. But too often the hybrids fall short in terms of the wines they produce. Sometimes they're just rejected out of hand even when superior to comparable vinifera varieties. So the other, and final, solution was to graph European vines onto North American or hybrid rootstocks. That is how it’s now done in virtually all wine regions where phylloxera is an issue. There are some exceptions; Chile, for example, has very strict importation laws and has managed to keep the bug out. These days, research into rootstocks is as important as research in grape growing and winemaking.

April 4, 2011

More is not always better


    Allowing vines to produce too many grapes, resulting in wines that are hollow, watery and characterless. *

Grapevines are fussy things. Normally they just want to take over a small region of the planet and be left alone. But grape growers have other plans. They want grapes. An orderly vineyard might be nice too. So they plant in rows and prune the vines to keep down their prolific growth. Interestingly, when challenged this way, grapevines tend to produce more grapes – and that’s good for the grower. But at a certain point, the vine produces too many grapes, or at least too many to produce a quality wine.

For the grape farmer there is a trade off. Increase the yield and there will be more grapes to sell. But that lowers the grapes’ quality. In an environment where grape prices are fixed, that can be bad for the wineries that purchase grapes. If grapes are priced the same, then a ton of grapes costs the same regardless of quality. There is no incentive for the grower to increase quality since quality costs a lot to produce but would not result in a better price for the grapes. For the lowest quality of wine, this may be OK (it is far from actually a good thing) but it is impossible to make great wine from over-cropped grapes.

In an over-cropped situation, the vine has to parcel out nutrients equally. Whether the vineyard is targeting 2 tons per acre of 10 tons per acre, the vine can only deliver the same amount of nutrients. In general, you’ll find quality wine made from low yield vineyards – the 2 tons-per-acre is typical – and cheap bulk wines from the 10-tons-per-acre crops and some times more.

What constitutes low or high yield depends on a number of factors, and principally the grape variety. Some grapes can produce top quality at higher yields while others must be severely restricted. The corollary is that over-cropping is also relative, as far as the actual tonnage per acre goes, and varies from grape to grape. But whatever the ideal yield is for a given grape and terroir, over-cropping is over-cropping and the result is almost always a wine that is “character challenged”.