Sugar in Wine: How Much Is There & How It Tastes

We all eat too much sugar. Fact. Even the most health-conscious fitness fanatics eat too much sugar. It’s everywhere, and it’s almost impossible to avoid. If you eat any processed food then BAM  – I guarantee that it will be in there somewhere. It’s hidden away in our drinks, disguised in our fruit, boldly showing its poisonous face in our yummy snacks. Don’t even get me started on ketchup. And yes, it’s in our wine too. 

There are a few things we can all say for sure about sugar. Number one, it tastes great. And number two? It’s really, really confusing. Will it too much lead to obesity and tooth decay? Is all sugar bad sugar or can it sometimes be a good thing? Is sugar ever needed (and if so, in which cases)?  More importantly, are your favourite sweet wines worth investing in through your wine investing app

While we can all agree that sugar isn’t exactly a health food, there’s a lot of misinformation about the sweet stuff. For instance, some types of sugar are healthier than others. And yes, sometimes a great fine wine needs to be a bit of a sweet sensation in order for it to sing.

Why Is Sugar in Wine Important?

As serious wine investors and amateur oenologists, I think we can credit ourselves with a little bit of wine knowledge. We know the difference between our Bordeauxs and our Bourgounes and our Chardonnays and our Chablis’. We believe that “dry” wine is better on the palette as well as for the portfolio (not to mention the waistline). We tend to frown upon sweet wines. Bar the glorious, syrupy Sauternes produced by Chateau d’Yquem, we think that sweet wines are both cheap and unsophisticated. This begs the question – is sugar in wine important? And if so, why?

Simply put, yes. Sugar is indispensable to wine. It is at the heart of what makes winemaking possible and the delicate touch of the winemaker’s hand can make or break a vintage. Grapes are coddled all season by their producers in order to ensure they have maximum ripeness, and it is only when the sacred fruit is deemed completely ready that the harvest can begin. The optimum ripeness equals the optimum alcohol level. So yes, (natural) sugar is very important in wine.

Why so? During the process of fermentation, sugar from wine grapes is broken down and converted by yeast into alcohol (ethanol) and carbon dioxide. This sugar provides food for the yeast to ferment and, ultimately, helps it on its way to becoming a “fine wine”. This is called “residual sugar,” or RS by industry professionals. 

Finished wine is considered dry if it has less than 2 g of sugar per litre post-fermentation. Most wines are dry, especially reds, although do not be fooled into thinking that there isn’t any sugar in red wine. For info, higher levels of RS classify a wine as medium-dry or medium-sweet. More than 45 g per litre is considered sweet.

To make it simple, the EU has laid out some guidelines for still wines as per the below: 

4 g/l – 12 g/l Medium dry / demi-sec

12 g/l – 45 g/l   Medium (Medium sweet)

More than 45 g/l Sweet / Doux

For sparkling wines, the labelling terms are regulated as follows:

Up to 3 g/l               Brut Nature

Up to 6 g/l               Extra Brut

Up to 12 g/l             Brut

12 g/l–17 g/l            Extra Dry / Extra Sec

17 g/l –32 g/l       Dry / Sec

32 g/l –50 g/l          Demi-sec

More than 50 g/l Sweet / Doux

Additionally, wines can be enhanced with added sugar and was a common process known as chaptalisation during the 18th and 19th centuries. This is where sugar or grape concentrate was added to the fermenting grapes in order to boost the alcohol level in the finished wine. It was more prevalent in northern hemisphere countries (hello, France), as the cooler climates did not allow the grapes to ripen consistently. It’s less common today;  improved viticulture helps wine growers get the grapes ripe and climate change is giving us warmer vintages.

Chapitalisation is not illegal in France (contrary to say, Italy), but the process is very strictly controlled. For example, a Bourgogne Blanc (Chardonnay) is required to have at least 10.5% ABV (alcohol by volume) but if the harvested grapes are overly sour (acidic), chapitalisation or adding sugar will make sure that the wine reaches the minimum required alcohol percentage. While chaptalisation adds sugar, it should not sweeten the wine; it’s simply meant to give the yeast enough fuel to turn it into alcohol.

As many of you may already know, in 2018, Margaux third growth Château Giscours was famously accused of chapitalising their 2016 vintage. The claim was strongly denied and the estate appealed against the suspended prison sentences and the €200,000 fine. The Bordeaux tribunal also ordered that the wine affected (around 39,700 litres), must be destroyed. The fine wine estate does, however, admit some sugar was added to “Vat 7” in error, rather than on purpose.

The timing was particularly bad, as the news came on the back of the news that one of the region’s leading négociant’s, Grands Vins de Gironde, has been charged with widespread fraud. It was also just weeks prior to the Giscours En Primeur campaign, which greatly affected their sales for 2017. 

How Does Sugar in Wine Taste?

When discussing how much sugar is in wine, one should never lose sight of the fact that alcohol is fermented sugar. Thus all wines, even red, have sugar in them. Put simply, ripe fruit tastes sweet. Sweet wines, even dry wines, have sweet flavours, and you’ll see wine tasting terms such as “perfumed”, “rich” and “demi-sec” being used to describe these. Higher wine alcohol levels wines can also taste sweet, as the glycerin in alcohol gives a perception of sweetness.

Contrary to what you might think, sweet tastes are harder for the palette to pick up (in contrast to sensitivity to bitterness or sourness), with all but the pros being able to notice the difference in RS between a dry red and a Champagne. What’s more, tannins and acidity in wine can mask the perception of the taste. 

Which Wines Have the Least Sugar?

The problem is, it is quite hard to tell which wines, red or white, have the least sugar. Wineries are not required by law to have their product details on their label (such as with fizzy drinks for example). The good news is that good producers, aka those who produce fine, investable wines will usually have easily downloadable tech sheets available which will include all tasting notes as well as details such as the RS. 

As mentioned, dry wines (anything on or under 4 g of sugar per litre) are lower in RS so look for these next time you’re in the off-license. As amateur oenologists and investors, we suspect you already know how to identify a dry wine (we have a great, in-depth article on what is dry wine if you don’t). However, for info, we have made a quick cheat list for you to memorise below. 

Some of the red wines with the least sugar are:

  • Cabernet Sauvignon 
  • Pinot Noir
  • Sangiovese 
  • Merlot 
  • Malbec
  • Syrah 
  • Garnacha 
  • Zinfandel 

Some of the white wines with the least sugar are:

  • Sauvignon Blanc
  • Chardonnay 
  • Pinot Gris
  • Riesling
  • Moscato

Our final word of advice on how to spot a low RS wine is to splash the cash. Higher quality wines tend to have lower RS as they are built for ageing, and thus have a higher tannic level in their youth. Tannins play an exceptionally important role when it comes to wine ageing. The evolution of the grape tannins contributes to the wine’s evolution in both barrel and bottle, notably the overall aroma, flavour, colour and textural characteristics. As the tannic molecules fix onto the proteins and start to polymerise (the scientists among you will know what that means, otherwise it’s not important to know), the flavours in the wine start to change and sediment is formed. The polymerised tannins soften in taste (ergo they no longer taste bitter or astringent). But, as a key element in the structure of the wine, the presence of tannin will give the wine a greater ageing potential – that mouth dryness caused by tannic astringency will make wines feel ‘fresher’ as the primary fruit aromas get lost.

This is why some red wines, particularly those with high acidity and a high tannin structure are best when they have been laid down for a few years. And high tannin usually equals low RS. 

But before trying a bottle of sweet wine, why not check out these wine tasting terms & tips for wine tasting!

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