Traditional balsamic vinegar
[4] The first generally accepted document referring to a precious vinegar produced in the area of Modena and Reggio Emilia is the poem written in the 12th century by the monk Donizo of Canossa,[5] although the word balsamic are never mentioned.
[7] As far as the aging method is concerned, it is very similar to the Solera system used in Spain after the Napoleonic Wars which spread abroad after the second half of the 19th century.
[a][13] At present, however, independent agencies that officially state TBV authenticity of both the TBVM and TBVRE have not adopted it or any analogous procedure as an evaluation system.
Making process of the TBV starts from freshly squeezed grape juice and finishes with sensory evaluation of the aged vinegar.
The production regulations require starting from a grape must with 15 °Bx at least to reach at the end of cooking 30 °Bx for TBVRE; for TBVM, the lower limit is not specified.
In addition, cooking promotes nonenzymatic browning chemical reactions involving sugar conversion, formation of high molecular weight melanoidins[15] and furanic compounds such as 5-(hydroxymethyl)furfural (HMF).
The fermentation of sugar into alcohol is carried out by yeasts belonging to a plethora of species and genera, and occurs in anaerobic conditions.
[14] In the past, the idea of a commensalistic interaction between yeasts and acetic acid bacteria existed, but recently the scalar fermentation has been suggested.
The chemical composition of TBV is highly variable, depending on the alcohol, sugar, and acid content of the fermented grape must, the cooking modality, and the oxidation temperature.
The barrel set is a series of at least five wooden casks arranged according to a decreasing size scale, where the product undergoes profound changes over time.
As widely known for the wine production, it is reasonable to suppose that the wood acts as a semipermeable filter for the transfer of small molecules towards the ambient while it retains important volatile compounds such as the acetic acid.
A theoretical model has been recently developed to estimate the mean age of TBV requiring refilling, withdrawn, and casks volumes as input data.
Yield indicates the ability of a barrel set to concentrate cooked must at given operating conditions being dependent on the rate of water loss by evaporation.
[23] Applying the spreadsheet of the theoretical model[13] to a barrel set as in figure, the residence time obtained as a function of withdrawn quantity and evaporation rate is plotted in the concerning graph.
[30] An important class of minor compounds, recently investigated, is that known as melanoidins, an heterogeneous mixture of polymers arising from sugar degradation reactions activated during cooking of the grape must.
