European Oak Varieties
French oak from centuries-old forests has asserted its dominance in the wine world with aplomb and skill as well as price premium, but it wasn’t always thus. The Bordelais used to be more than happy with Hungarian and Baltic oak, and a comeback for non-French wood is being quietly asserted. It is over the last quarter of a century that oaks from the same species as French – Quercus petraea (sessile oak) and Quercus robur (pedunculate oak) from other European forests have been making a return into the wine world, especially those from the post-communist world. Other woods, notably cherry and acacia have long been used in traditional European wine making. American oak is from a different species (Q. Alba) and is not considered good enough to make wine or spirits in Europe.
This resurgence is not a question of economics. Research at the Australian Wine Research Institute (AWRI) by Mark Sefton et al. found that the geographical origin of oak for barrels resulted in differing amounts of flavour compounds in wines. Though the only Q. robur (a.k.a. English, French, Russian etc.) studied were from different regions in France, it’s not far-fetched to make an extrapolation for flavour difference to different zones and climates outside France.The origin of species: Hungary, Russia, Slavonia. While both Q. robur and Q. petraea are grown throughout Europe, including mixed forests in France, there is more Q. robur further east, though some areas also have concentrations of Q. petraea. Jean-Pierre Giraud, commercial director at Taransaud cooperage, whose owners Chene & Cie have a joint venture in Kadar Hungary, explained “sessile is what we consider medium to tight grain and pedunculate is medium to wide.” But the two species tend not to be separated in the cooperage process. Geographical origin and quality of the oak are more important than the species of oak. Giraud said “The Hungarian oak trees where we source at Kadar are smaller in diameter because they age in the hills in the east of Hungary, in Tokaj, in a continental climate. This oak gives structure to the wine, with elegant tannins and spicy toasted bread.”In southern Hungary, the Trust Hungary cooperage has been working since the early 1990s. Their managing director, James Molnar said: “Hungary sits in the Carpathian basin, between the mountains of Austria, with Slovakia to the north and the Ukraine to the east. Warm airs come over the Adriatic giving a Mediterranean climate in the basin. As you leave the Carpathian basin, the chemical and physical characters of the trees change, with smaller trees as it gets colder to the north. Hungarian oak has higher levels of eugenol compounds than French – nutmeg, clove, oriental sweet spice characters.” He added “if I’m in a blind tasting, I usually look for mid palate weight. Hungarian oak generally adds a rich sensation of weight and texture in the middle of your mouth. I find French oak has more breadth in the mid palate.”Even earlier onto the eastern scene was Seguin-Moreau in the late 1980s. They use Russian oak from the Caucasus, the north east corner of the Black Sea which also has a more continental climate than France. Research by Andrei Prida prior to his current role of research and development manager at Seguin-Moreau and Jean-Louis Puech at INRA-Montpellier (National Institute for Agronomy Research) found that the “most important features for distinguishing origin [French versus Eastern European] were volatile compounds including eugenol, 2-phenylethanol, vanillin, and syringaldehyde, which give a slightly spicy, mild vanilla aroma.” Prida added “we observed forest effects more when we consider remote sourcing. So we talk about French, Eastern European (Russian, Bulgarian, Romanian) and Caucasian zones separated by hundreds of kilometres.”Prida said: “We observed that Caucasian oak is characterised by moderate tannin and aromatic impact. This oak allows winemakers to obtain fresh and mineral wines, while generic Eastern European oak is mostly well suited for wines which require big tannin impact; it’s good for building wine structure. But we cannot say one is more valuable than another, and the choice is mostly related to the profile of wine and oenological results needed“. Rioja producer Marques de Vargas was one of the early trial partners, in 1991, using Russian oak from Seguin-Moreau. They were so happy with the results that they created a new wine – Marques de Vargas Reserva Privada, made in very good vintages, and made using 100% Russian oak barrique size 225 litres. The winery’s winemaker, Francisco Javier Pérez Ruiz de Vergara, said: “The Russian oak gives different aromas from French oak during the ageing, more elegant and sweeter aromas.” Over on the north-west side of the Black Sea, a swathe of forested territory continues along similar latitudes, and now comprises Romania, north-eastern Croatia, Hungary and Austria. This is Slavonian oak territory, a staple of traditional European winemaking. According to the FAO (Food and Agriculture Organisation of the United Nations), Slavonian oaks of the Danubian plains of ex-Yugoslavia (part of Hungary before the first world war) are of very high quality. Bosnia and Croatia equally split the majority, with the rest divided between Slovenia, Serbia and Montenegro. They suggest the best quality Slavonian oak comes from the north-eastern plains of Croatia. Slavonian oak is widely used in the traditional and classic Italian wines of the Veneto, Tuscany and Piedmont. Respect for the fruit by Slavonian oak was top of the list for Amarone producers. Riccardo Tedeschi of Agricola F.lli Tedeschi said: “Slavonian oak has a less fine grain [than French], which is fine for big barrels; it’s more consistent over time, at least two years. We use 25-50 hectolitres (hl) for Amarone. It gives a less intense flavour than French oak, sweeter aromas, less structure than French. As our grapes are delicate, bigger oak is gentler.” Luca Speri, of Speri Viticoltori, added “with Slavonian oak, micro-oxygenation is long, and the wine needs time to be ready. With Slavonian oak, the wine can live longer in the bottle.” For their Amarone, the Allegrini family pursue a mixed French/Slavonian oak philosophy, as Marilisa Allegrini explained: “our Amarone goes to new French barrique for 18 months.Then the wine is finished in old, 80 hl, Slavonian oak for 7 months. Slavonian oak breathes and integrates the French oak into the wine, and it eliminates the variation between the oak barriques. We don’t use stainless steel because it gives bitterness. “In Tuscany, the blending and integration facility of Slavonian casks is also valued at Felsina, where Giuseppe Mazzocolin said “we use Slavonian oak for our Chianti Colli Senesi and Chianti Classico, since their main qualities are their drinkability and the refreshing crispness of a young sangiovese. Slavonian oak has a beneficial effect on the wine’s structure,” adding, “please keep in mind that we work predominantly with sangiovese, [which is] technically temperamental. It consistently requires a light hand on the oak.” Optimising the use of oak for micro-oxygenation properties rather than oak characters continues to be important where fruit, rather than ‘boisée’ characters are sought. Mazzocolin said “We place great importance on employing barrels that have been used in preceding years, since the wine that has been in them has lent them certain characteristics that reflect the Felsina terroir. They are excellent up to the third or fourth usage, and in this respect Slavonian oak gives us better rotational effectiveness.” North east Italy neighbours Slavonia. Here, at Tenuta Manicor, proprietor Michael Count Goëss-Enzenberg, said: “The advantage we see in our oak is, besides the harmony with our wines, that it is very subtle on our fruit, and on the aromas and the minerality our wines show. It just respects the character of our wines more.”
