First of all, as my blog post stresses, there’s Grappa and there’s Grappa. Take the time to find the quality brands (such as Nonino, Bocchino, Berta or Bepi Tosolini) as they are well worth the effort and are a wonderful spirit. The difference is explained through the production methods which I’ve bashed out below.
Grappa can be made from a mixture of pomaces, or vinaccia as the Italians call it, the skins of grapes remaining after the grapes have been pressed to make wine, from different sources or from one grape variety. Carefully selected vinaccia is taken to the distillery as soon as the wine has been drawn off, and the stalks are removed. The stalks should not be used in production, although the rubbish producers throw it all in and you can really taste it straight away in the final product. This is the first stage in making top-quality Grappa. There are some exceptions to this, as some distilleries may also use the seeds and small quantities of pulp.
Even if a vineyard produces great wines it doesn’t always mean the vinaccia from that winery will produce good Grappa; the trusted grape doesn’t guarantee the quality. The fresher and softer the pomace is, the better the final Grappa will be. Ideally, the leftovers should be collected and fermented within 24 to 48 hours after the wine has been drawn off.
The next stage is to put the vinaccia into stainless steel tanks (Nonino has exceptionally beautiful tanks!) ready for the fermentation process where the sugars are converted to alcohol. The grape skins naturally collect yeast at the vineyard, therefore it is important to constantly control the use of the yeast during this process. Both temperatures and pH levels are carefully controlled. The vinaccia from red grapes has already undergone alcoholic fermentation during wine making as the skins are left with the juice during fermentation to give the red colour to the wine. It can therefore be distilled immediately when making Grappa. The vinaccia from white grapes, on the other hand, does not contain ethanol but contains sugars that are fermented by spontaneous anaerobic fermentation during their storage period.
The Nonino distillery uses steam batch rather than bain-marie boilers, which are either vacuum or pressure stills. These steam stills, working non-stop 24 hours a day (but only during the harvest), allow it to distil fresh, perfect pomace immediately after fermentation. The distillation of fresh vinaccia is necessary to obtain pure and elegant Grappa with all the scents and tastes of the original wine variety. Artisanal batch distillation equipment consists of batch feeding of the machinery, which is filled up and unloaded each time it is heated for distillation. The batch machinery allows the distiller to follow the operations closely, maintain the quality of the raw material by controlling the temperatures and methods used during the distillation, and to intervene at the opportune moment to remove the ‘heads’ and the ‘tails’, retaining only the purest and best part of the distillate: the ‘heart’.
Artisanal batch distillation, also considered as a Nonino-inspired method, requires a fresh primary product, fermented at a controlled temperature and immediately followed by distillation, avoiding silage (fermented cattle food) and the formation of methyl alcohol and demethylation. Most Grappa distilleries use continuous industrial machinery that is automatic, calibrated in advance and involves the constant feeding of raw material through the distillation machinery. The vinaccia is added without the distiller being able to control or intervene in the process during distillation. As the removal of the ‘heads’ and the ‘tails’ is pre-programmed, the final product lacks the freshness and characteristics that for Nonino are two of the most important parts of the process.
The final part of the process is the ageing in different wooden barrels. At Nonino they use 1855 barrels made of Nevers, Limousin and Grésigne oak, former Sherry barrels, and acacia, wild cherry and pear barrels. After ageing, the distillates are bottled without the addition of flavour and colour additives. However, some companies purchase full-proof Grappa from another company and dilute it with demineralised water, which, sadly, allows them, by law, to claim it as their own.