Sweetness Indicator

W

Warren Edwardes

Warren Edwardes
How to arrive at a Sweetness of Wine indicator?

The terms, Dry, Medium Dry etc. (certainly as defined by The EU) are very broad.

Some wineries / distributors have sweetness indicators 1 to 9.

Residual Sugar in grams/litre quoted on bottles would be a good start.

But we know that acidity changes the impression of sweetness. Sort of a wind chill factor.

So lets also quote the acidity in grams/litre. Trouble is some refer to acidity in Sulphuric acid and others in Tartaric acid terms. One is 1.53 times the other. Or the other way round?

How about pH? Sounds good.

So I say do away with talk of "Give me a nice Dry White" and lets ask for a 6 grams/litre wine with 2.9 pH shall we?

But how about simplifying with a composite Sweetness Score?

Off the top of my head I would say:

SS = RS x pH

RS is residual sugar in grams/litre.

How does this sound?
 
pH is no good. It ignores the buffering capacity of the acids. It's a long story, but no time now.
 
originally posted by SFJoe:
pH is no good. It ignores the buffering capacity of the acids. It's a long story, but no time now.
Click to expand...

Additionally, the SS formula assumes a linear response, which is nave. The best solution overall is probably Olivier Humbrecht's index of perceived sweetness. Perhaps the EU could codify the scale so that there's broad agreement over what constitutes a 1, 5, 8, etc.

Mark Lipton
 
originally posted by MLipton:
originally posted by SFJoe:
pH is no good. It ignores the buffering capacity of the acids. It's a long story, but no time now.
Click to expand...

Additionally, the SS formula assumes a linear response, which is nave. The best solution overall is probably Olivier Humbrecht's index of perceived sweetness. Perhaps the EU could codify the scale so that there's broad agreement over what constitutes a 1, 5, 8, etc.

Mark Lipton
Click to expand...

I understand that the Olivier Humbrecht scale is a subjective scale based on the OH palate. Though obviously he knows the Residual Sugar, Acidity in grams/litre and pH. But I don't believe it is based on a declared mathematical formula. (Is it?)

Many UK supermarkets have a similar scale based on individual palates. So a 3 on a Spanish wine based on the particular firm's Spanish wine buyer's palate might be a 2 on a French wine based on the French wine buyer's palate. And the Spanish wine's 2 might be a 3 in a different supermarket.

How are "Dry" etc. defined in the US? Is there a legal definition?

But if food can be labelled with calories and if wine can have alcohol % declared objectively and numerically why can't the sweetness and the acidity be declared (in pH or grams/litre tartaric)?

Subjectivity is a problem in that nobody wants to buy a #3 or a Medium Dry White Wine.

If a client orders; "I'd like a nice dry white wine", s/he probably wants it with 12 grams per litre of residual sugar and a pH of 4 and perhaps slightly pink.
 
originally posted by Yixin:
Use g/l acid, log scale. But not convinced this would really be useful.
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No, it wouldn't.

Buffering capacity at pH is what determines perceived acidity. The wine will move in pH when it encounters your mouth.

But the "total acid" metric ignores whether it is a strong acid like malic, or a milder one like lactic. This plus pH all matter.
 
originally posted by Warren Edwardes:
But if food can be labelled with calories and if wine can have alcohol % declared objectively and numerically why can't the sweetness and the acidity be declared (in pH or grams/litre tartaric)?
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You're not comparing like to like.

Calories and alcohol can be measured. How fat something will make you, or how drunk it gets you, will vary from person to person.

What I can measure is fructose (e.g.) but "sweetness" is a matter of opinion (and, apparently, several complicated interactions).
 
originally posted by maureen:
what about terry thiese's "sense of sweetness" scoring - doesn't that do it for you, Warren?
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If it is subjective based on "finger in the air" scoring and personal judg(e)ment then it is not for me.

There is already a legal EU definition based on residual sugar and acidity defined by The EU of broad categories Dry, Medium Dry etc.

Sure the concept is based on so many things including Malic v Lactic which hadn't occurred to me.

My chemistry is weak - gave up after failing to control a pipette in High School and swallowing a dosage of potassium permanganate.

Is there a linear relationship between pH and acidity in g/l?

Does Malolactic fermentation change pH or measured (as opposed to perceived) acidity?

But on a principal component analysis surely Residual Sugar and Acidity (pH or g/l) quoted separately or combined to form a score would be better and more objective than the EU broad categories or subjective "finger in the air" scores?

Does the US have a definition of "Dry"? Does it go along with the EU definitions?
 
originally posted by Warren Edwardes:


My chemistry is weak - gave up after failing to control a pipette in High School and swallowing a dosage of potassium permanganate.
Click to expand...

You were mouth pipetting KMnO4??? Unless you went to High School prior to WW II, Warren, whoever designed that lab should have been flogged. Un-fucking-believable what some idiots will force students to do.

Is there a linear relationship between pH and acidity in g/l?
Click to expand...

Nope, logarithmic (base 10).

Does Malolactic fermentation change pH or measured (as opposed to perceived) acidity?
Click to expand...

It changes both pH and TA.

But on a principal component analysis surely Residual Sugar and Acidity (pH or g/l) quoted separately or combined to form a score would be better and more objective than the EU broad categories or subjective "finger in the air" scores?
Click to expand...

You seem to be quite reticent to use subjective assessments of sweet/dry, but those categories are fundamentally subjective. As SFJoe mentioned, buffering capactity plays a role and I suspect that there are several more confounding variables at work. Personally, I think that a subjective index is more reliable than the analytical data for determining taste. No reason not to include both, though. More information never hurt any consumer.

Mark Lipton
 
originally posted by MLipton:

Is there a linear relationship between pH and acidity in g/l?
Click to expand...

Nope, logarithmic (base 10).

Mark Lipton
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Is it monotonically increasing? i.e. Given 2 wines can one wine have a higher pH and a higher acidity in g/l than the other wine?

originally posted by MLipton:

You seem to be quite reticent to use subjective assessments of sweet/dry, but those categories are fundamentally subjective. As SFJoe mentioned, buffering capactity plays a role and I suspect that there are several more confounding variables at work. .

Mark Lipton
Click to expand...

I have a problem if 2 or more people can arrive at different scores of "sweetness". No problem with RP or Jancis points which clearly are subjective.

On a broad principal component basis I would have guessed the residual sugar would contribute 80%, acidity (pH or grams/litre) 15% and the rest 5% (just gut feel).

Do people disagree?
 
originally posted by Warren Edwardes:
I have a problem if 2 or more people can arrive at different scores of "sweetness". No problem with RP or Jancis points which clearly are subjective.

On a broad principal component basis I would have guessed the residual sugar would contribute 80%, acidity (pH or grams/litre) 15% and the rest 5% (just gut feel).

Do people disagree?
Click to expand...
I think you live in a fantasy world of simple additive mixtures. "Sweetness" is an opinion, not a measure.
 
originally posted by Jeff Grossman:
originally posted by Warren Edwardes:
I have a problem if 2 or more people can arrive at different scores of "sweetness". No problem with RP or Jancis points which clearly are subjective.

On a broad principal component basis I would have guessed the residual sugar would contribute 80%, acidity (pH or grams/litre) 15% and the rest 5% (just gut feel).

Do people disagree?
Click to expand...
I think you live in a fantasy world of simple additive mixtures. "Sweetness" is an opinion, not a measure.
Click to expand...

But there already is an objective legal measure of sweetness (in the EU) based on RS and Acidity in g/l.

I seek a just as objective and measurable refinement. i.e. No use of "Dry". "Medium Dry" etc. and statement of RS and acidity in g/l or pH or a formula combining RS and acidity g/l or pH.

Obviously the current legal definitions incorporate such a logical formula combining RS and acidity g/l tartaric.

IF (RS LE 4) OR [(RS LE 9) AND (RS-TA) LE 2)] THEN "Dry"

................

The European Union lays down sweetness terms:

In Article 16 COMMISSION REGULATION (EC) No 753/2002 of 29 April 2002 the following terms may only be used on the labels of table wines, table wines with a geographical indication and quality wines psr, with the exception of the quality liqueur wines psr and quality semi-sparkling wines psr covered by Article 39(1)(b):

(a) sec, trocken, secco, asciuttto, dry, tr, ngqy, seco, kuiva, droog or torrt, on condition that the wine concerned has a residual sugar content not exceeding: (i) 4 grams per litre; or (ii) 9 grams per litre, provided that the total acidity expressed as grams of tartaric acid per litre is not more than 2 grams below the residual sugar content;

(b) demi-sec, halbtrocken, abboccato, medium dry, halvtr, glngqoy, semiseco, meio seco, adamado, puolikuiva, halfdroog or halvtorrt, on condition that the wine concerned has a residual sugar content in excess of the maximum set at (a) but not exceeding: (i) 12 grams per litre; or (ii) 18 grams per litre, where the minimum total acidity has been set by the Member State;

(c) moelleux, lieblich, amabile, medium, medium sweet, halvsd, glcktjoy, semidulce, meio doce, puolimakea, halfzoet or halvsftt, on condition that the wine concerned has a residual sugar content higher than the maximum set at (b) but not more than 45 grams per litre;

(d) doux, sss, dolce, sweet, sd, cktjy, dulce, doce, makea, zoet or sftt, on condition that the wine concerned has a residual sugar content of at least 45 grams per litre.

Brut Nature - (no added sugar) up to 3 g per litre

Extra Brut - up to 6 g per litre

Brut - up to 15 g per litre

Extra Dry / Extra seco - between 12 and 20 g per litre

Dry / Sec / Seco - between 17 and 35 g per litre

Demi-Sec / Semi-seco - between 33 and 50 g per litre

Doux / Dulce - more than 50 g per litre

originally posted by SFJoe:
It is possible to have higher ta and higher pH at the same time. The general principles and simple math are here.
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Thanks. My maths is a few degrees better than my chemistry.

For all their faults objective measurable credit scores aren't going away.
 
originally posted by Warren Edwardes:
I seek a just as objective and measurable refinement. i.e. No use of "Dry". "Medium Dry" etc. and statement of RS and acidity in g/l or pH or a formula combining RS and acidity g/l or pH.

Obviously the current legal definitions incorporate such a logical formula combining RS and acidity g/l tartaric.

IF (RS LE 4) OR [(RS LE 9) AND (RS-TA) LE 2)] THEN "Dry"
Click to expand...
I'm confused, Warren. You don't like the EU's method because, although you call it "objective", you complain that it is not transparent because it uses code words that derive from formulas.

If that's how you feel, then why not just put RS and TA (and MA and LA and...) on the label? Why are you seeking to hide those facts behind some kind of "sweetness" measure? (IMO the public won't understand it and the wineaux won't believe it so you may as well put a picture of your dog on the label.)
 
I prefer the EU method to any subjective numbers or names - 1, 2, "Rather Dry" .. which vary from one wine buyer or producer to another.

I don't like their broad bands - "Dry" etc

I prefer (and do) quote RS on labels. In fact I'd like full info but only if there is a level playing field.

"Medium Dry" or "Medium Sweet" will not sell and so there are euphemisms such as "Off Dry", "Not Too Dry", "3" and so the EU definitions are in practice bypassed.

Initially I naively like an idiot quoted on my labels the legal terms "Dry", "Medium Dry", "Medium" but changed after a year to "Very Dry", "Quite Dry" and "Off Dry" (with RS) with excellent results.

I think RS on its own is a very good measure of "Sweetness" but not perfect.

I was wondering if RS could be objectively and mechanically tweaked to allow for TA (RS*) or pH (RS+) and if so how - starting with choice of TA or pH.

i.e What changes in RS and TA/pH produces no change in "Sweetness" agreeable to most/many members of this board? (keeping constant MA and LA balance). I don't have a feel for this.

But maybe RS and TA both declared is better than creating RS* and RS+

Or maybe my current practice of quoting just RS is OK for simplicity?
 
I would ignore pH, as I've mentioned. If you are away from the pKa of your acid, you will find the pH very mobile. Nothing wrong with quoting a total acid for the geeks, but be sure to give them the units, as you're aware.

Ridge, for one example, has had lots of technical information on their elegant label, and it doesn't seem to have cost them sales.
 
Great thanks.

So what changes in RS and TA produce no change in "Sweetness" in your opinion at , say, RS of 10 grams / litre and TA of 5 g/l Tartaric?

What would the TA have to be if the RS was 12 to result in the same "sweetness" as above (by your guess)?
 
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