'Standard' Acidity (etc) For Elderberry Blackberry / Any Country Wines

By the way, I presume that pH of around 3.3 is workable for a red fruit wine with no sugar added too?

Cheers, Jim

No I agree - if they did I'd have to roll my eyes. I like my wines dry, fairly tannic and hearty usually. Having guide figures is useful before taking the plunge. I am really hoping that after tasting again and pH testing I decide I can live with the levels - messing it around might be more of a nuisance and let down than having it slightly sour, but I will step into the dark shortly and see what I can see. At least the guide figures I have now can acts as a candle and are corroborated elsewhere online.

Jim

Sorry to be repetitious, but remember, sourness is a function of pH, and not directly correlated to total acidity.

Sure, cheers.

malic does NOT reduce pH more than tartaric. malic will buffer the pH higher.

Added to water, malic will result in a lower pH than tartaric. Any buffered solution will resist a change in pH. Malic only results in a higher pH when it is converted to lactic acid in a secondary fermentation (malolactic).

It is probably time for a review of wine acidity basics with Jack Keller

Converting malic to lactic acid reduces sourness, but tartaric has the lowest pH. Any serious discussion about winemaking with the Norton grape will involve dealing with high pH at fairly high TA due to the high ratio of malic acid.

Jack's article also gives a general answer to jim c's original question.

Stephen

In case anyone is interested I did pH measurements and found the wine to be at the low end of the range pH wise ~3.3 I did trials with .1 .

On bottling it still tastes very young, but not overpoweringly sour. I think in a couple of years it will be pretty good.

Jim

By the way stephen, that is where I got my data in the first place. I was looking to see if there were any comments specific to Elderberry. Most of the discussion was really built around fear of adjusting by taste, but I have done my best now, so I won't worry now, just wait a few months or a couple of years for the wine to come good :)

Thanks everyone for their comments!

Jim

Brain FART!

Agreed, I was in error. I was thinking of an article that I read not long ago, but numbers don't lie.

Acetic acid, a weak acid, donates a proton (hydrogen ion, highlighted in green) to water in an equilibrium reaction to give the acetate ion and the hydronium ion. Red: oxygen, black: carbon, white: hydrogen. An acid dissociation constant, Ka, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution. It is the equilibrium constant for a chemical reaction known as dissociation in the context of acid-base reactions. Where HA is a generic acid that dissociates by splitting into A-, known as the conjugate base of the acid, and the hydrogen ion or proton, H+, which, in the case of aqueous solutions, exists as a solvated hydronium ion. In the example shown in the figure, HA represents acetic acid, and A? the acetate ion. The chemical species HA, A- and H+ are said to be in equilibrium when their concentrations do not change with the passing of time. The dissociation constant (Ka) is usually written as a quotient of the equilibrium concentrations (in mol/L), denoted by [HA], [A-] and [H+]: Ka = [H+] [A-]/ [HA]

Due to the many orders of magnitude spanned by Ka values, a logarithmic measure of the acid dissociation constant is more commonly used in practice. pKa, which is equal to -log10 Ka, may also be referred to as an acid dissociation constant:

The larger the value of pKa, the smaller the extent of dissociation. A weak acid has a pKa value in the approximate range -2 to 12 in water. Acids with a pKa value of less than about -2 are said to be strong acids; a strong acid is almost completely dissociated in aqueous solution, to the extent that the concentration of the undissociated acid becomes undetectable. pKa values for strong acids can, however, be estimated by theoretical means or by extrapolating from measurements in non-aqueous solvents in which the dissociation constant is smaller, such as acetonitrile and dimethylsulfoxide.

Malic pKa1 = 3.4, pKa2 = 5.13

Tartaric pKa1 = 3.2, pKa2 = 4.8

The various acids in wine can't be identified by titration, therefore a standard is chosen. In France, total acidity is calculated as sulfuric. In California it is calculated as tartaric. Can you explain what you mean by high pH with high acid? citation please