Why does this wine taste the way it does?
Elements of wine
What factors go into making the wine in your glass? It’s not just the grape or grapes, but this is an important factor. It depends on geography too.
The kind of vineyard soil is critical, as is the landscape. The vine is a Mediterranean weed and if it encounters fertile soil, it runs riot, putting the emphasis on leaves rather than fruit. Vines produce the best wine grapes when they have to struggle. Provided the fertility is pretty low, clay soils tend to make big wines, for example in the Ribera del Duero, Napa and Barossa. Chalk is part of Champagne’s secret, while Kimmeridgian limestone determines much of the taste of Chablis. There are hundreds of such examples. n Try this for Kimmeridgian limestone: Pierre Ponnelle Chablis, France. (€17.50, widely available) n
And so to geography. How high above sea level? The Eden Valley is cooler than its neighbour, the Barossa, and makes quite different wines. Is it near a mountain? Alsace wines owe much to being the rain shadow of the Vosges mountains. How does the wind blow? The Mistral blows across the Rhône valley and delivers a drying concentration. Is it very warm and sunny by day and very cool at night? These conditions should deliver a good balance between ripeness and freshness. Is it very warm all the time? This will produce very ripe grape. n Try this for the cool Eden Valley: Penfolds Koonunga Hill Autumn Riesling, Australia. (€18.50, independents) n
How a wine ends up depends to some extent on the yield of the vineyard. A good average for quality wine is 50 to 60 hl/ha, while some of the best Burgundies come out at 35hl/ha or even less. It’s easy to see how quality costs money! n Try this when you win the Lotto: Chateau d’Yquem 2004, France. (€224, mitchellandson.com)
What happens in the winery?
The first thing a winemaker needs to decide when the grapes get to the winery is the choice between fermenting away from oxygen or with it. Delicate white wines, and most Sauvignon Blanc and Riesling, will be fermented with minimal oxygen and at cool temperatures. High quality Chardonnays, for example, will often be made in contact with oxygen and, for a time, with the grape skins. In most white wines, the stems will have been removed as they cause bitterness.
Red wine grapes are generally de-stemmed, crushed and the juice, along with the skins, go into the fermentation tank. Some stems are usually added back at this stage in order to adjust the tannin levels. In Burgundy whole bunches, with their stems, are often fermented.
Natural yeasts, on the skins and the stems, will start the fermentation (common in Europe) or cloned, selected yeast strains will be used (more in the New World). Yeasts have a huge impact on the taste of wine, thanks to their ability to release flavour and aroma compounds from the grape. n Try this for wild yeast: Greywacke Wild Ferment Sauvignon Blanc, New Zealand. (€30, independents) n
White wines tend to be fermented in sealed tanks. With reds, the skins float at the top of open tanks and form a protective layer. In both cases, this keeps air from the fermenting wine.
The layer of skins may be punched down – think of it like stirring the tea pot – to extract more colour and flavour, a process the French call ‘pigeage’. Where the winemaker wants to achieve this, but with more oxygenation, the wine may be pumped over: a hose from the bottom of the tank dumps the fermenting juice and skins back in at the top several times a day.
Fermentation produces heat and this needs to be controlled, especially when making white wines. Big, rich reds ferment between 22C and 30C, while light, aromatic whites are kept to about 12C. Temperature control is usually managed by a ‘jacket’ of cold water around the tank.
That’s the alcoholic fermentation. This is followed, in most instances, by second one, malo-lactic fermentation in which malic acid (which tastes sharp, like apple juice) is turned into lactic acid (think milk and cream).
Some sweet wines are made by fortifying with extra alcohol to stop the fermentation while there’s still lots of fruit sugar in the wine. Port is a famous example. But there are wines that are naturally sweet, made from super-ripe grapes that have shrivelled, reducing their water content and boosting the concentration of sugar. Often these grapes have been colonised by a fungus called noble rot. It makes the skins more porous and adds a flavour of its own. The most famous example is Sauternes, made in Bordeaux. n For Sauternes try: Tesco Finest Sauternes 2015, France. (€16/37.5cl, Tesco)
Seasoning
Oak and wine have gone together for centuries. Old oak barrels are good for ageing wines but they don’t have much effect on the taste. New oak barrels do. These will have been charred on the inside so that taste of the oak isn’t raw and overly tannic. This is why you often get the smell, and the taste, of vanilla – oak contains vanillin, just like the spice – and some smokiness. n Try this for smoky oak and blackcurrant: d’Arenberg The High Trellis Cabernet Sauvignon, Australia. (€14.71, SuperValu)
▪ New oak barrels are very expensive but winemakers can economise by shaving a layer off the inside of used barrels to expose fresh wood. They can also give cheap wines a touch of oak influence by using ‘tea bags’ as they are called in the trade: mesh bags of oak chips that have been charred. These can be dunked until the wine gets enough oak influence. The difference between tea bagged and barrel-aged wines is significant. With dunking, the oak element seems to float above wine. Barrel-aged wines have really integrated oak.
In recent years, some red wines have had coffee and chocolate extracts added, which is fine if it floats your boat. But in my book, that’s not wine. It’s a cocktail.
Another influence on the taste of wine, specifically high quality white wines, is what the French call ‘bâtonnage’, which basically means stirring. After fermentation, the dead yeast cells fall to the bottom of the fermentation vessel and start to break down. This sediment is called the lees and it releases additional flavour compounds. To maximise this effect, winemakers stir this stuff up into the wine on a regular basis. Bâtonnage can give wines an aroma of freshly baked bread and sometimes a buttery character. n Try this for bâtonnage: Chateau du Coing de Saint-Fiacre Muscadet de Sèvre et Maine sur Lie 2016, France. (€18.50, Baggot St Wines, lecaveau.ie)
Storing your wine
Most of us (a) don’t have anything remotely resembling a cellar and (b) buy wine to drink within days. But if you want to keep a stash of bottles, bear in mind a few things. First, keep it away from strong light and ideally below 20C but don’t let it freeze and avoid big temperature variations. Keep it away from strong odours – don’t put the firelighters on top of the bottles!
Ageing process
More than 95% of wines are made to be consumed within one to three years and they don’t change a lot in that time. Fine wines that have been made to age can become amazingly complex over time as tannins soften and tastes and smells that simply weren’t there at first develop and emerge.
If you want to try your hand at ageing a few bottles – and it doesn’t have to be madly expensive stuff – you need somewhere dark, with a pretty consistent temperature of between 12C and 15C and a bit of humidity is good too. Just make sure you store any bottle with a cork, as against a screwcap, on its side. Some very high-quality wines come with screwcaps, so there’s no need to be snobbish!
▪ Try these for ageing up to five years:
Specially Selected Clare Valley Riesling 2020, Australia (€9.99, Aldi)
Bouvet-Ladubay Saumur Blanc Nonpareille 2016, France (€25, whelehanswines.ie)
Chateau Gardegan Bordeaux Supèrieur 2018, France. (€15.95, O’Brien’s) ▪ Try this for a fully mature wine: Les Hauts de Naudon Bordeaux Supèrieur 2014, France. (€19,
Dunnes Stores)