What subsequent analyses are relevant?

There is a large analytical pool of oenological analyses available at harvest arrival. The analyses listed here are the most common and the most relevant in a decision-making process.

Potential alcoholic strength by volume (PABV)

To determine this, it is necessary to know the must's initial sugar concentration and then estimate the conversion of the latter into alcohol by the yeasts.
The estimated amount of sugar needed to obtain 1% ethanol is 16.83 g/L, but this varies according to the yeast strain and the type of wine (white or red). Various analysis methods exist:

Hydrometer
Refractometer
Electronic density meter
FTIR

Total acidity

The wine or must's total acidity is the sum of the acidities that can be titrated by adding an alkaline solution. The average content in wines is between 3 and 6 g/L H2SO4 equivalent. The main component of the total acidity is tartaric acid. Next comes malic acid (then lactic acid after malolactic fermentation) and citric acid. These three acids are the most important.
These three acid components give an idea of the acids present in the future wine and it is the indicator typically used to determine the sugar/acid ratio at harvest time.

Available nitrogen

This is one of the most important measurements taken when the harvest arrives at the winery. It is composed of organic nitrogen, i.e. amino acids (except proline) and ammoniacal nitrogen.
Yeasts use it for their growth in order to synthesize the proteins necessary for their development. The must is generally considered to contain two-thirds amino acids and one-third ammoniacal nitrogen. In reality, this ratio is not always exact.
See the section on available nitrogen for additional information.

The pH

The pH is calculated from the H3O+ ions concentration (often simplified to H+ in texts). A wine's pH is generally between 2.8 and 4.
This is a very important parameter because it has an impact on the wine's microbiological stability. The lower it is, the more difficult it is for harmful organisms to develop.
It also has an impact on redox reactions, the quantity of active SO2 in the wine, tartaric stability and organoleptic perceptions. The pH therefore has an effect on a wine's ageing potential.

Malic acid

Malic acid is a diacid produced during grape berry development. It is a very important molecule in the grapes' biochemical cycles.
During the winemaking process, it is broken down during malolactic fermentation into lactic acid which is a monoacid, resulting a decrease in total acidity and pH. An early dosage gives an indication of whether malolactic fermentation will be potentially difficult or not depending on the quantity of malic acid. For more details, see the chapter on malolactic fermentation.