Oliver - I always thought it was around 2 g/l but there aren’t really any regs from the TTB regarding “dry” so it’s open to interpretation. I think I got that 10 pct from Wine Spectator, believe it or not and it stuck with me because it seemed pretty high. I never checked it.
Still, in Germany, they can call a wine dry at over 4 g/l if it has sufficient acidity.
I think what you found in Italy isn’t that unusual - I was tasting dozens of Hungarian wines a couple years ago and expected them to be dry, which is what they were labeled, and for me each one seemed to have some sugar. Looking at the stats, they were only about 2.5 g/l max, which is pretty low, but that was enough to matter.
I wasn’t talking about TTB usage, I was talking about normal non-bureaucratic usage in the US and in Italy. Germany is a special case, and perhaps Hungary too, for the same reason.
If you want to cheaply check the RS of wine at home, you can buy a graduated cylinder and a hydrometer measuring oechsle. The rule of thumb is to add 5 to the oechsle number (corrected for temperature) and multiply by 2 to get the RS in grams per liter.
-2 Oe would be 6 g/l
5 Oe is 20 g/l
-5 is completely dry
This is not exact, but you’ll get a ballpark estimate within a gram or two. It becomes less accurate for very sweet wines (say over 25 g/l.)
Larry, I think there’s a huge need to mention “dry” when marketing wines. I have a strong inkling hey sell better. Seems like a good enough reason to me.
Not sure they would sell better - sometimes leaving things off in our industry ‘implies’ certain things, and they would probably want to ‘imply’ that the wines are dry because it’s not as ‘cool’ to drink an ‘off dry’ red (-:
That was really brought home in a components tasting I attended at a lab in Napa 20+ years ago. They served two versions using the same base wine with the same R.S. but with different acid levels. Then they did a pair with the same acidity but different R.S. Your perception of sweetness acidity was a function of both, not either one in isolation – that was plain.
I don’t doubt that there are lots of wines with R.S. But I would guess that some of the really big California wines, white and red, taste sweet not so much because of R.S., but because their acids are low and the alcohols make it seem sweet. Who can tell without a lab analysis, really?
Here’s a link to the International Riesling Foundation’s ‘dryness’ scale. It takes into account the ratio of RS to acid to determine different levels of dryness:
This is a very interesting thread. Personally I’m most interested in understanding total sugar content in wine (RS is some percentage of total sugar, most of it I assume). For example if I buy a bottle of coconut water or fruit juice the nutrition label tells me (assuming its right, which is a conversation in itself) how much total sugar is present (by serving). Of course wine isn’t labeled (another separate conversation), so I’m trying to figure out how I can determine total sugar.
According to Wikipedia, it comes in a form that’s 68% sugar, but I would guess it’s added before or during fermentation, in which case presumably the winemaker can control how much if any sugar is left unfermented.
My guess is that it also gets added just prior to bottling to increase color - and pop the RS. Have not used myself nor do I know of any specific wineries using it, but it’s not uncommon to add ‘concentrate’ like this to boost RS in wines prior to bottling. Have seen it done with other varieties (but not to add color).
Yes - I endured a lecture on this once - it is all hazy (like anything to do with chemistry for me), but I recall there are fermentable and nonfermentable sugars. Some are in the grapes and some complex “-ose” chains can polymerize during fermentation. Different sugars are perceived as having different sweetness levels (on a 100 point scale sucrose = 100, fructose 172, inverted sugar 130, glucose 74, arabinose 50, sorbitol 48, glycerol 48, xylose 40, maltose 32, rhamnose 32, galactose 32, raffinose 23, lactose 16, to name a few). You can have two wines same Alc %, same measured RS, same acidity, etc. but one might taste sweeter (or alternately one might taste a bit harsher).
If I understand your question, RS is all the sugar left over after fermentation is complete. A little sugar always remains, even if the fermentation finishes completely, but sometimes wineries add sweetness, which of course leads to higher RS. (‘Residual’ Sugar is a bit misleading, in commercial winemaking I think it’s usually added, not ‘residual’ at all.)
Sampled Little Black Dress and I would put it in this category originally mentioned also. Tech sheet indicates 1.3 RS for their Pinot, but is that still on the high side for an entry level red with medium acid?
On a related note, what would be cheapest and most DIY method of testing sugar, alcohol and pH content of the wine? Is there one equipment that can test for all three?
One is not sure if the sugar is residual or dosage. I’ve heard of vintners using yeasts that died out when the wine reaches the 15-16% alcohol level. But some really ripe fruit still has sugar that hasn’t been converted at that level. So the fermentation is complete, the yeast die, but residual sugar remains. I’ve heard of this with both syrahs and zins, with the RS there mainly to mask some of the alcohol.
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