From strength comes forth sweetness
Is alcohol sweet? Does a high alcohol level in a wine make it taste sweeter? That's the conventional wisdom, and it's been mine too. But it's always good to have one's prejudices and ingrained assumptions questioned. If a shiraz with 15.5% alcohol tastes sweet because of the alcohol (ie the residual sugar is negligible), then why doesn't a fino sherry at the same alcohol level taste sweet?
That was the simple question posed by someone on Jancis Robinson's website forum recently, and I thought the answers were interesting and that they were worth sharing with a few geeks out there. (Actually someone did point out that "Very little regarding wine is 'simple'".)
One of the most useful answers quoted from the great Emile Peynaud's book The taste of Wine. He says that as well as sugars, there are other sweet substances in wine "which have one or more alcoholic functions, formed during the course of alcoholic fermentation" - ethyl alcohol, glycerol, butylene glycol, inositol, sorbitol.
Peynaud tested various alcohol strengths in water, and found that it "has a vaguely sweet, lightly sugary taste, clearly apparent by comparison with water but without the particular taste of alcohol being recognizable as such. The taste is different from the sweet taste of sugar while belonging to the same family of tastes. At 10% of alcohol there is a strong sweet taste along with a warm slightly burning sensation. This solution clearly shows the complex taste of alcohol. affecting both taste buds and the mucous membranes at the same time."
Then he talks, of course, about the other aspects of a wine's balance that affect the sensation of sweetness - acid, bitterness and saltiness.
The contributor to the forum who quoted Peynaud (at much greater length than this) also pointed out the contribution of fruitiness, and concluded that "I guess that in the end, it is just not about alcohol alone or sugar alone but a very complex interplay of many elements."
Another contributor suggested looking at the role of volatile esters here: 'Volatile esters are one of the major flavour components of fruit and can be perceived as "sweet" despite not actually being sugars. Look up esters in wikipedia, or google "sweetness and volatile esters" and you'll see what I mean. And as alcohol is one base components of an ester, it makes sense that a wine higher in alcohol might generate more esters. I saw this in a previous life in the whisky business - whisky can appear "sweet", or even "fruity" in varying degrees - despite having neither sugar nor fruit in it.'
But perhaps the question remains, why a wine at 15% alcohol seems sweeter than a sherry at 15%.
Again, it's useful to talk about balance (one can never get away from the concept of balance in wine!): Another comment was:
'To my simple mind is exactly the presence or absence of fruit (not alone, but in combination with acidity and tannin levels), that make the perception of sweetness of two wines with the same alcohol differ: I'm not a sherry expert or afficionado, but I believe that a Fino's hallmarks would be a certain nuttiness, saltiness and maybe even earthyness in the nicest possible way - none of which we associate with sweetness. The blackcurrant, blackberry aromas of an Aussie Shiraz with the same amount of alcohol and res. sugar as the Fino would make it come across a lot sweeter, as we associate these aromas with fruit and sugar. It's the way we have been 'programmed' and try as much as we like to be totally objective in tasting, we can not totally block these experiences.'
A number of people had mentioned glycerol as a factor in the difference between the sweetnesses of wine and sherry, and this was supported by David Bird MW, chemist and author of Understanding wine technology:
'I think that the apparent sweetness is due to glycerol. It is a widely known fact that glycerol is formed during the fermentation of sugar. So, the more sugar in the original must, the more alcohol and the more glycerol. As glycerol has a sweet, smooth taste, so wines with high alcohol tend to taste smooth and sweet. If the alcohol is added, as with sherry or any other fortified wine, this extra glycerol is not present, hence the natural wines taste sweeter.'
So. We can happily continue finding alcoholic wines a bit sweet (and finding that another cause for objection to them, if we wish), and know that there's good reason for it. It's always comforting to have science supporting our beliefs.
- Tim James's blog
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Re: From strength comes forth sweetness
Dear Tim,
this has often been the debate between the new world and the more classic european producers. But before I make my point, a few truths have to be said, and even linked to your articles about Chenin blanc, and sauvignon sweetness that you have been discussing over the the last weeks. You say that in France, as an exemple, we can call dry a wine under 4 grams, but it must be remembered that most of the appelation have very strict rules, and that many do not accept any level over 2 grams of residual sugar per litre; and failure to do so, you cant have it certified, so you cant sell it!
In many european countries, leaving sweetness in the wine, like 3 or 4 grams, is seen as a way to hide defaults, and compensate the lack of real depth, minerality, ripeness and complexity.
If we take the exemple of Vouvray, the semi sweet was mostly produced on the years when the quality of the crop was not healthy, and the very high acidity combined with some rustic flavours led the winemakers to keep some sugar to help fruits and palatabilty. But the good years, only dry and noble late was produced...
You would never find a Chassagne, a Chablis, a Sancerre, Bordeaux, a white Chateauneuf du Pape with more than 2 g/l of sugar, unless the producer has been cheating at the "labelisation", the French certification.
When we look at the german wines, the tradition of leaving residual sugar was traditionnaly a way to deal with the acidity, and make the wine drinkable, an showing a way to support the subtle nobility of the riesling.
This being said, I will not debate on the glycol/glycerol level in the wine. Surely some yeast will create more of these subproducts, and the higher alcohol fermented will produce more of it on an absolute value.
But having managed for years a wine trophy, I had access to the WSR2 of many of our best wines. And where in France the analysis would show an average at 1,2/1,5 gram, the average in South Africa is between 3 and 5. If you combine this with the level of acidity which is naturally lower in South Africa, the perception of these few grams always make the wine clearly sweeter. The glycerol level is just adding to it, but is far from being the main reason.
On white wine, these few grams are helping to support the fruit, and make the wine far more mouthfulling. On the red wine, it sometime helps hidding tannins still hard, either by improper ripeness, or by shorter maturation.
I mean that residual sugar is often a shortcut to make the wine more palatable, and not a judgment of value. It is as well linked to a new culture of wine drinking. 25 years ago, the first big brands of Australia started to land in Europe, and the first sweet shiraz, (not syrah...), leaded by the famous Rosemount Shiraz, brought to wine a new generation of drinkers, drinkers that considered the wine a social drink, and not a food partner. The UK market started to drink afterwork, following the Victorian laws, and a sweeter wine was more adapted to a dry drinking, I mean a drinking with no food.
In the US, the Fetzer Chardonnay has been, at the same moment in time, creating a new type of wine... the alcohol level was a consequence of a search of more immediate fruits, for a generation of drinkers that wanted more immediate physical feelings than waiting for 20 years to start enjoying a wine.
So South Africa followed the trend, and in Europe, entry level wines, not subject to the AOC rules, did the same, mostly in languedoc and spain, to meet the demand of this new growing market.
So the alcohol is not the culprit, but a decision. When you taste some Chateauneuf du Pape, Priorat or some Roussillon wines, you will have 15 or 16 alcohol wines, but no sweetness, not from the residual, not the alcohol, not the sweetish overburnt or americanised wood.
We can have our 15° wines less sweet, but then they will become less palatable for immediate consumption, so it might make your banker very unhappy. It is not a judgement on wines with more sweetness, but they must be accepted for what they are, teasers... some wines are even creating a marketing tool with it, adding some exotic other flavours to these.... and it sells. A few years ago I made 3 barrels of Shiraz called the OZ Slut, with american oak, overextraction, 15+, and 6grams... it sold within two weeks, and I still have some cases of my normal dry syrah, drinking beautifully now...the slut is dead, but luckily all drunk.
And for the sherry, the dry extract, and the perceived minerality and acidity, will help to create a gap with the Australian shiraz, but still, make sure that your Shiraz does not have a 5g residual on the top of the 15,5°... and this is why it is still a known practice in Australia to add salt, to balance the sweetness, and reduce the sweetness perception, but still keep the sweet mouthfeel... luckily this is forbidden in South Africa.
I hope I gave you a different insight, and you will forgive my English neologisms, I am just an arrogant Frenchman after all...