Acidity - How are you sensing it?

[Polymer]

There are two parts to Acidity (as far as I know)....pH and TA. pH is how acidic it is, TA Is how much acid is in the wine.

Are you finding you're more sensitive or feel acidity in a wine purely on the pH? Or does TA make more of a difference to you? Or is it a combination of the two?

I've also noticed that for me, some wines I don't feel the acid on the attack like many other wines but I will feel it a bit more on the finish but I don't know why that is....and coming from someone that enjoys a lot of acidity, it is a bit weird...

When you sense acid in a wine do you enjoy that sensation or not enjoy it at all?

[rossmckay]

There are two parts to Acidity (as far as I know)....pH and TA. pH is how acidic it is, TA Is how much acid is in the wine.

Are you finding you're more sensitive or feel acidity in a wine purely on the pH? Or does TA make more of a difference to you? Or is it a combination of the two?

How do you tell the difference?

[Polymer]

Well that's what I'm asking...

When you're tasting a wine and you're sensing different things with the acidity..are you noticing you feel a wine is more acidic when the pH is really low but not necessarily the TA? Or more so in reverse?

This assumes that whatever they're telling you measurement wise is accurate....

Its not something easy to tell...I'm asking so I can get some ideas on what I'm sensing when tasting wine...why sometimes I feel this or that....

I know, for example, that if I have a wine with a low pH AND high TA, the wine is very likely to be very acidic..Texture/mouthfeel wise I can sense that....I'd also say in general, lower pH wines I feel a sharper acid...but that isn't always the case either....

[rossmckay]

I've never thought about the sensory impact, time to hit the books.

This is a good overview article http://gwi.missouri.edu/publications/2013spring.pdf which serves to show how complex the relationship between pH and TA is. It seems to ask more questions than it answers, so down the rabbit hole.

One of the references to that article is a 1980 paper which is summarised here http://goo.gl/dNSphu . The "sourness, as well as organoleptic properties" dot point is relevant but still doesn't answer your question.

[The fish]

For me - acid sensation is more a matter of the location in the mouth where the 'feeling' is occurring. eg. the tongue - which part?, the teeth (rieslings in particular ), the gums, the palate of the mouth and so on. Having said that telling TA and pH apart based on the location of those sensations is that actually possible? How would one train oneself to do that?

Edit: there's your MW thesis subject Mr McKay...

[rossmckay]

For me - acid sensation is more a matter of the location in the mouth where the 'feeling' is occurring. eg. the tongue - which part?, the teeth (rieslings in particular ), the gums, the palate of the mouth and so on. Having said that telling TA and pH apart based on the location of those sensations is that actually possible? How would one train oneself to do that?

Edit: there's your MW thesis subject Mr McKay...

As far as actually tasting/assessing the level of acid, I use the tilt the head forward technique, which works to isolate it for me.

As far as a thesis goes, I love the way you're thinking Matt. Thinking about how they balance so well in countries like Germany and Spain. Hmmm, should be able to get a few trips out of that.

[conformistpete]

I can't say I have thought about how to taste or feel the difference in TA or pH. However as a simple test of whether the wine feels or is acidic I tend to do the drible test. If after a mouthful of wine I can feel my saliva glands working and saliva would dribble out ....
Oh and I do like a bit of acid.


http://www.dunndunnplus.com/#!WSET-Dipl ... 900F4538C9



Snip:
You may find this hard to separate from alcohol (both cause a burning, mouth watering sensation).
Tip: use the dribble test, look how quickly your mouth fills with saliva after spitting the wine. The faster this happens, the more acid there is, consider the persistence of the acid in the mouth.

[Polymer]

I'm pretty much an acid fiend but there are always some wines that throw me off a bit...Here are a few..

Pewsey Vale Contours almost always seems to be lower acid to me than what other people are sensing. I think I've had one that wasn't like that..
Helm Riesling - We had this recently and the acidity didn't seem too high except I could tell it was there on the finish..while others felt it was high in acidity (and I believe them).
Tyrrells Johnno's Semillon - This to me is like the Contours...I can sense acid on the finish but the handful of times I've had this, I'm not getting the same acid hit on the attack that I'm expecting even though the stats say this should be relatively high acid..
Some Vouvrays - Some Huets are like this for me as well...

Could it be the type of acid? Maybe I don't detect certain types very well?

Another flipside to that:

In the US they measure TA the same way as Australia (whereas Europe they do it differently). There were quite a few wines I thought had very good acidity yet their pH and TA would have suggested I would have found them lacking a bit...I find that in Australia as well but not often...

[JamieBahrain]

Heartburn!

[conformistpete]

Could it be the type of acid? Maybe I don't detect certain types very well?

...

Could it be residual sugar tempering the feeling of acid in your mouth?

[Polymer]

I don't think that is it.....I'm actually a big fan of very high acid and a slight amount of residual sugar and that is one thing I'm good at sensing...Yes, it'll balance it out but you still feel the acid and you can feel the residual sugar soften it a bit (even if it is 2-3g/L), but that particular sensation is different (to me anyways).

[dingozegan]

Are you finding you're more sensitive or feel acidity in a wine purely on the pH? Or does TA make more of a difference to you? Or is it a combination of the two?

I've also noticed that for me, some wines I don't feel the acid on the attack like many other wines but I will feel it a bit more on the finish but I don't know why that is....and coming from someone that enjoys a lot of acidity, it is a bit weird...

When you sense acid in a wine do you enjoy that sensation or not enjoy it at all?

Like you, I tend to enjoy wines with higher acidity than many people.

It's difficult to separate pH and TA. Granted, a wine with a lower pH but the same TA would (all other things being equal) taste more acidic, but there are so many things that confound the issue it's difficult to make generalisations. So many other compounds buffer the pH, for example (that's why reds tend to have higher pH's for the same TA compared to whites). I think most people would notice a TA shift of 1 g/L more than a pH shift of 0.1 - but how meaningful is that when it's so wine style dependent anyway(?).

I think the type of acids play a huge role in our impression of acidity too. Wines with malic acid present a completely different acid profile (than those without malic): they aren't just softer on the palate, the presence of malic acid impacts where you notice acidity on the palate aswell (as you mention, some wines' acidity might be experienced more on the attack, others more in the finish). Acids like succinic and lactic, and other compounds such as alcohol and pheols, can modify where and how the impression of acidity is experienced on the palate.

In short, it's a combination of pH, TA, and whole lot of other compounds.

[Polymer]

I can definitely see it being how I perceive the different acids...maybe I'm in tuned to some and not in tune to others...

I mean, I guess from a tasting standpoint it doesn't really matter..it is all what my impression is of the wine...but I do like trying to understand what it is that is making up a wine in a bit greater detail....Essentially, if I were to make or describe to someone what I wanted them it to be texture wise, I would want to have some understanding of what needs to be done to get me there...

[rossmckay]

Just asked a winemaker and higher pH can be sensed as a 'soapy' mouthfeel.

[redstuff]

I guess we could make up some standard solutions of known concentration of each of the acids in wine. Then taste them at different concentrations and mix and match etc. That might give you feel for how pH relates to in mouth acidity/taste. Probably want to do it blind at first.

[rossmckay]

I guess we could make up some standard solutions of known concentration of each of the acids in wine. Then taste them at different concentrations and mix and match etc. That might give you feel for how pH relates to in mouth acidity/taste. Probably want to do it blind at first.

Sounds like a plan

[rooman]

The topic of acid in Australian wines flared up about 5 years ago when Andrew Jefford gave a speech criticizing the excessive addition of acid to wines made in Australia.

Here are some interesting comments made at the time:

http://www.ft.com/intl/cms/s/2/993125ce ... abdc0.html

http://www.simonwoods.com/andrew-jeffor ... -industry/

[rossmckay]

Was in class today and asked the question. One response I thought was intriguing.

The acid is felt further back in the mouth in comparison to the fruit flavours, which makes sense when you think of the reason and circumstances in which one adds acid.

[Polymer]

Well did some extra research..

I think the US measures TA differently..they only measure tartaric acid..which now makes a bit more sense....Whereas with TA in Australia it is multiple types of acid....could explain a few things I think...

[dingozegan]

I think the US measures TA differently..they only measure tartaric acid..which now makes a bit more sense....Whereas with TA in Australia it is multiple types of acid....could explain a few things I think...

The US and Australia measure Titratable Acidity (TA) the same way. Titratable acidity is a measure of how much of a base (like sodium hydroxide) you have to add to an acidic solution (like wine) to achieve a particular pH. Because there are numerous acids in wine, the base reacts with all of them (to a point), but the titratable acidity concentration that's quoted is expressed as if all the acid that had been titrated (reacted with the base) were tartaric acid. (Australia and the USA use the same pH end-point standard too.)

In France, the titratable acidity concentration that's quoted is expressed as if all the acid that had been titrated were sulphuric acid, not tartaric. This means, for a wine with technically the same titratable acidity, the values quoted in France are lower than the values quoted in Australia/USA (sulphuric acid is "more acid"). You can convert a TA as sulphuric (grams per litre) to a TA as tartaric (grams per litre) by multiplying by 1.53. Hope that helps.

[grapeobserver]

Good topic. Supplementing the great comments from dingozegan, since it's on the shelf behind me, from Jamie Goode, Wine Science (2014) pp199-201:

1. The main organic acids found in grapes are tartaric, malic and citric. Tartaric acid is the key grape acid, and is a strong/hard acid. Malic is "green".
2. Other organic acids found in grapes are D-gluconic acid, mucic acid, coumaric acid and coumaryl tartaric acid.
3. Further acids are produced in fermentation, such as succinic, lactic and acetic acids. Ascorbic acid may be added. Lactic is a soft acid with some sourness.
4. PH is the concentration of hydrogen ions in a solution. Lower the number, the higher the acidity (and a negative logarithmic scale).
5. Acidification is usually done with tartaric acid. As a rule of thumb, 0.5-1g per litre of tartaric acid lowers PH by 0.1.
6. High PH wines can have a smooth mouthfeel. Lower PH generally lowers risk of oxidation and microbial spoilage. PH for whites typically 3-3.3 and for reds 3.3-3.6.
7. TA refers to both total acidity and titratable acidity, which are different. Total acidity is the total of organic acids in a wine. Harder to measure in practice. Titratable acidity looks at the ability of the acid in the wine to neutralise an alkaline substance. It is lower than total acidity but used as an approximation for it. The unit is expressed in grams per litre and most countries use "tartaric acid equivalent". Some Euro countries use sulphuric acid equivalent which is ~2/3 of the tartaric acid equivalent.
8. Studies suggest it is TA that gives the taste of acidity, rather than PH. But they are usually correlated.
9. The impression of sweetness is countered by acidity e.g. brut Champagne with 8-10g/l of dosage, but doesn't (always) taste sweet.

The spell checker went crazy with a couple of the more obscure acids, so apologies for any misspellings.