is taste affected by TA or pH

Both. At the same TA, the same wine will appear more acidic at a lower pH than at a higher pH. Likewise for the same pH, differing TAs.

Ben

Improved Winemaking

Ben is right, both effect taste as they are different measures of the same thing -- acidity -- and acidity effects that tartness of the wine. But neither is a very good measure of how your wine will taste. You need to have some idea of pH if you want to use the right amount of K-metabisulfite to protect your wine and it should be in certain ranges for proper aging. But when it comes to taste there is no measure like the tongue. Use your own taste to do final adjustments.

Ray

Hmm still not clear. Say I make 2 solutions of 0.6% tartaric acid solution. Glass I has a ph of, say, 3.5. I then magically alter glass II so that none of the acid disassociates (no H+ ions) - it will have a pH of approx 7. How will the taste differ between glass I and II? Will glass II taste acidic (0.6% TA but no H+)?

Euan

Hmm, still not clear.

Say I make 3 solutions of tartaric acid by adding 6, 8 and 10g of tartaric acid to 1000ml of water. Solution I will have a pH of 3.5 (or thereabouts). I then manipulate solutions II + III so that they have the same pH. I don't know if this can be done but lets say I can control the level of H+ disassociation.

Will the 3 solutions taste any different? If they do, then it is due to something other than the acidity (acid salts?). TA measures potential H+ disassocation, pH measures actual H+ disassocation?

Euan

I have never been able to perform magic so I do not know how magic will effect the taste of the solution. The only way I know how to do what you are suggesting is to add a base to the solution that would bind the H+ ions and neutralize them. That would certainly effect the taste, maybe poisonously depending on what you use for a base. But then you are talking about the taste of acid plus base.

I think you are making something easy complex. Just get the pH in the right range and then use your tongue and adjust acidity to taste by adding acid.

Ray

You could manipulate that pH by adding potassium, but in _my_ opinion it is _easier_ to base _my_ acid adjustments on TA than pH.

Grape wine pH is affected by potassium content, but manipulating potassium is not the only variable. If it were that easy winemaking would be a science, not an art. You could just get things identical chemically and life would be easy. It doesn't seem to work that way.

I still find myself fine tuning my acid adjustment regimes after 10 years of winemaking and I measure everything. If I had to rate those measurements against taste, it would be 25% measured value, 75% taste. When I started it would have been the opposite since I had no young wine tasting experience and it really does evolve.

My hesitation on using pH as a guide is based on the fact it's a log value, I hope to get it in a range of 3.3 to 3.6 in a finished wine. If it's not and I like the wine, I let that slip. Winemaking is like most things, a series of best compromises available at the time.

The only thing I can tell you is what I do. I don't worry about red wine pH's as high as 3.85, I rarely bottle a dry red at more that 6.0 g/l. I think TA less than 5 g/l is often pretty bland. I think TA higher than 6 g/l can lead to a tart aftertaste that I like to avoid. White wines tolerate slightly higher TA, and sweet wines even higher. And if I like the taste of the wine, I discard those rules and watch that wine as it evolves.

Joe

snipped-for-privacy@hotmail.com wrote:

From what I've read, TA influences the taste 10:1 over pH. However, both are important for different reasons, the pH is important for stability and in particular for the amount of sulfite required. The higher the pH the more sulfite needed to produce adequate free SO2 to protect the wine. As others have said, the real acid test (pun intended) is really in the taste!