Optimal pH, brix and tannins?

[Ty520]

Does anyone know of a resource that documents "optimal" starting and finishing ph, brix, TA, tannins of various varietals?

 

[cmason1957]

Those numbers probably don't really exist. I have had very good wines that end above 4.0 ph and low ta and some that were below 3.2 and high ta. Best advice I ever read was get the ph between 3.3 and 3.7, ta so that the taste is good. Taste trumps numbers.

 

[Rice_Guy]

@Ty520 optimum implies that there is one best and everything else comes in as second rate. Wine is an interaction of several variables, and the optimum balance point changes if any one variable is changed, ie there are many optimum chemistry numbers to start with. My read is when you talk varieties the mind set is “how can I make these pigs ears int silk purses?”

Optimum pH, this is involved in the ionization reaction with metabisulphite therefore lower is always better. The bottom of the range is where the yeast are killed off/ stall by accumulated pH, alcohol, CO2;
red grape has tannin in the skin (an antioxidant) therefore pH 3.5 is good
white grape and fruit pH 3.3 to 3.2 is good
Gravity/ brix; you are really asking what alcohol is wanted which is a style or a target market. the low end is 10% alcohol and the high is 18%, the low side has increased risk of infection and at the high end alcohol is toxic to yeast, ,,, all that said if you sterile filter you can put alcohol as low as you want without risk.
Finished gravity again is personal preference. For the US market a little sugar scores higher/ sells better.
Tannin; I am not aware of any university/ research center/ commercial lab testing tannin as a routine, however apple varieties do have numbers associated with them. Optimum is a moving target since tannin reacts/ polymerizes and falls out as the wine ages.
TA; this is balanced with finished sugar and tannin. The New Cidermakers Handbook has the best discussion I have seen.
Another point on optimum is it depends on the age or redox potential of the liquid when the wine is graded. This leads to shelf life and the “neavu“ wine will have different targets than one that targets a five year market.

Jackish; Modern Winemaking about 1982 is an excellent reference on where the chemistry should be to make grape wines. ,,,, However optimum implies $100 per bottle quality. In this case one wants the TA as low as possible, 0.5 or even 0.4%, in which case the sweetness in the alcohol balances the acid flavor without residual sugar. (pH must not move since it is in the Ka of sulphite). If you are going into modern references look at the university folks as UC Davis and The Australian Wine Reaearch Institute ,,,, or The Journal of Viticulture and Enology.

 

[Ty520]

@Ty520 optimum implies that there is one best and everything else comes in as second rate. Wine is an interaction of several variables, and the optimum balance point changes if any one variable is changed, ie there are many optimum chemistry numbers to start with. My read is when you talk varieties the mind set is “how can I make these pigs ears int silk purses?”

Optimal wasn't the right word choice - more like an industry standard typical bracketed range

 

[balatonwine]

more like an industry standard typical bracketed range

From:

https://viticulture.unl.edu/publication/Harvest Parameters.pdf

Suggested levels for white wine grapes:

°Brix – 18 to 22
pH – 3.2 to 3.0 (sic*)
TA – 0.8 to 1.2

Suggested levels for red wine grapes:

°Brix – 21 to 24
pH – 3.4 to 3.5
TA – 0.6 to 1.2


* ... as I think this is a typo, and more likely 3.3