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Why Technical Data Leads Us Down The Wrong Street

By Charles Olken

I have a friend in the winewriting business who is known, behind his back, as Dr. pH because he has concluded that only wines of a certain pH (defined as the decimal logarithm of the reciprocal of the hydrogen ion activity in an acqueous solution) are worthy of his intentions. Okay, now repeat after me. I don’t care.

Now that I have that out of my system, I can tell you with a straight face that the pH measurement in wine is related to the overall acidity of that wine. Typically, wines with very high overall acidity measure near to 3.0 pH and wines with what tasters might think of as lower acidity measure close to and occasionally surpass 4.0 pH. Since very few bottles of wine ever tell you what the pH of the wine happens to be, this information seems only to be important before the fact to my friend.

He has relatives, of a sort, in the folks who will tell you that they never drink a wine whose alcohol is over 14.0% by volume (sometimes referred to as 14.% ABV). It is true that the higher the alcohol, the less of it you can drink before feeling the effects. And it is also true that wines with higher alcohols can also have a hot finish. We could spend a couple of days discussing how correct or not wine labels and their statements of alcohol content happen to be, but the real question is why.

And the real answer to those who would judge wine by tech sheet content rather than by taste is “do you like wine or are you a statistician”?

It is at this point that I will confess that I read the tech sheets that sometimes accompany wines arriving at my door and are also sometimes posted on winery web sites. But, I read them after tasting the wine. There are times when the numbers explain why a wine tastes the way it does. There are also times when the numbers are less than helpful, and my experience is that the better the wine, the less important the numbers are.

Numbers lead us down the wrong street if we rely on them instead of relying on analysis by mouth, i. e., tasting the wine. A winemaker friend was involved in the study of technical data for Chateau Petrus, one of the most expensive Bordeaux wines in the world at upwards of $2,000 per bottle for newly released vintages. The findings, done at the University of California, Davis, the foremost university for winemaker training in the country and one of the most respected worldwide, was that Petrus typical had a pH near to 4.0. Anyone who refused to even taste wines with pHs above 3.6 would simply dismiss Petrus out of hand.

The same is true for alcohol level. While it is true that a 16% alcohol wine will knock you on your backside about one-third faster than a 12% wine, those comparisons are not really about apples and apples. More likely, those who argue against wines in excess of 14% ABV are drinking wines somewhere near 13%. And basic mathematics will tell you that the difference in total alcohol intake between the two is about an ounce or so in half a bottle.

My advice to those who think that they can drink more than half a bottle of wine at 13% ABV is “don’t”. If you are drinking more than half a bottle of wine with anything other than a long and filling meal, you are chasing inebriation and denying it.

There are clues in the tech sheets that reveal lots about a wine. Reading them is useful to Steve Eliot and myself in understanding what we have just evaluated with the label hidden. But, very little in a tech sheet will tell us about wine quality. Two wines with identical alcohol and pH levels can taste entirely differently. And while my friend, Dr. pH, will tell me that a wine with high pH cannot possibly age in the bottle, I simply remind him of Chateau Petrus, not because it costs so darn much, but because it has a proven track record of ageworthiness—and, come to think of it, so do a whole raft of locally produced wines whose ability to improve in the bottle is no longer in doubt because we now have the track record to know otherwise.

No need to stop reading technical information if that is of interest to you, but please do not judge the bottle by its cover. Taste its contents. That is the only true measure of a wine.


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by TomHill
Posted on:12/29/2014 10:16:11 AM

Nice rant, Charlie. Your Dr.pH is a poor/misguided soul. The correlation of pH and TA (Total Acidity or Titratable Acidity, measure as gm/100 ml) is an imperfect one. A reading of Amerine & Roessler he would find that one's sense of acidity in wine is much more closely correlated w/ TA, not pH.

   I do tend to agree w/ Dr.pH that the high acidity (as measured as pH)  is important to the ageibilty of wine. This is why simple Oz Rieslings; German Mosels, (old-time) Alsatian Rieslings can age into such amazing old-bones. But, as you correctly point out w/ the Petrus example, high acidity is not a necessary condition for ageibility. There are plenty of examples of low-acidity wines, particularly redds, that do age well.

   As you like to point out, it's not about the

Cut-Off Midstream
by TomHill
Posted on:12/29/2014 10:20:11 AM

..... numbers (or the process) behind the wine, it's all about what's in the glass before us. Couldn't agree more about that, Charlie.



The last thing I look at
by doug wilder
Posted on:12/29/2014 1:11:00 PM

Are Tech Sheets. When boxes are opened, the information goes in an inbox. The less I know about production, price, blend, etc while tasting. I don't need any of that until I start to compile my notes. True, I hardly even look at pH or TA and never enumerate in a review. There may be a 'low acid' remark to generally describe the style, but I don't think many consumers bother with it.

I get it. But...
by gabe
Posted on:12/30/2014 1:45:49 PM

As a consumer, I agree that those numbers are mostly unimportant.  However, as a winemaker, I can't think of a number that is more important than pH.  If nothing else, it makes a hell of a lot more sense than being obsessed with ABV.  Unlike ABV, the pH of a wine will tell you what to expect from taste and ageability.  However, like all other numbers, it is easy to manipulate, and should not be taken as gospel.

As for the Petrus example, there are multiple explainations why it holds up at a higher pH.  It could be fining agents and filteration used to stabilize the wine, it could be that Cab Sauv is a sturdier grape capable of holding steady at a higher pH, it could just be that 4.0 pH was from a hot year, and is being balanced by higher alcohols, higher BRIX, and higher TA.  But the bottom line is that it is really interesting stuff (if you are a total nerd like me).


Pick A Number-- Any Number
by Charlie Olken
Posted on:12/30/2014 3:06:00 PM

The beauty of tasting blind is that numbers and label information are not part of the evaluation equation. No doubt that they can offer explanation after the fact, but also that numbers by themselves are not definitions. 

Gabe, there are probably many reasons why pH in Cab Sv can be higher in wines that age well than in some other varieties. PS is another that often defies conventional logic.  

It is the rigid adherence to numbers as a substitute for tasting judgment that bugs me and became the genesis for this column. 

wine tasting vs. wine making
by gabe
Posted on:12/30/2014 6:17:13 PM


      I totally get it.  And like I said about number manipulation, it is really easy to add acid or water to change the pH or ABV, so using those numbers to evaluate wine quality is a definite mistake.  As somone who's job is to evaluate wine quality, I respect your decision to avoid looking at those numbers.

     But as a winemaker, my most important job is to asses the quality of a wine without basing my opinion on taste, because the taste of a wine is 100% garaunteed to change throughout the process.  Ultimately, every decision I make is an educated guess.  And perhaps a winemaker with more experience can be less dependant on numbers.  I am always trying to move in that direction.  But if I am going to use numbers to predict how my wine is going to turn out, pH has repeatedly proved to be the most useful number of the bunch.

Amen, Brother
by Charlie Olken
Posted on:12/30/2014 7:41:27 PM


Not for the first time, Gabe, I am reminded of the difference between my role as taster of finished wines and your responsibility to make those wines. On the whole, I think my job is easier than yours. Thanks for doing the heavy lifting.

mutual respect
by gabe
Posted on:12/30/2014 11:27:06 PM

I have judged a wine competition before, so I know for a fact that your job is not easy.  I also know that it would be nearly impossible to pay my bills without people like you to promote quality wines to the public.  Plus, I really dig your writing.  Let's just say that we are thankful for each other.

Technical Data
by Bob Henry
Posted on:2/4/2015 9:44:42 PM

What else do folks waggishly say behind Ph.D(an)'s back?

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