The house of Grenier, an innovator in creating new types of conical oak tanks and foudres, is located in the heart of Burgundy and supplies the most renowned wineries in France and abroad. It uses top quality French oak, with small pores (≤ 2mm), from the best forests in the regions of Allier, Nevers and Centre France.
The natural seasoning of oak takes place over a period of about 4 years in large parks with significant rainfall, in order to break down and flush out the phenolic substances in the oak.
Vats with oak of a thickness ranging from 40-60 mm, depending on the volume of the vat, may be open style or closed with a stainless steel lid. The latter make up Grenier’s «Vinistock» line.
Some are equipped with high quality 316L stainless steel accessories.
The cap thickness is 4mm, with a cap hatch of 0.20 to 1.60 m and an opening of 40 or 50mm.
There are three types of doors
- Oval, 430 x 310mm, with a thickness of 10mm, opening inwards
- Rectangular, 310 x 430mm, with a thickness of 10mm, opening outwards, with pressure resistance up to 2.5 bar, and low positioning for easy removal of the marc
-Round, with 180° opening and a thickness of 10mm, positioned on the outer side of the bottom of the tank for easy emptying out of the marc, with pressure resistance up to 3,5 bar.
Valves for total and partial emptying of the vat, a sampler with a plunger, and a thermometer with internal protection.
Removable cooling jacket, with a very large cooling surface and removable filters.
A fixed, internal, single or double heat exchanger with multiple coils positioned at a tangent to the walls.
Particular care is given to the construction of the vat, the perfect and sturdy fitting of the stainless steel surfaces to the oak, and the light, slow toasting of the inner surface.
The low flame respects the oak, so as not to alter its properties and to avoid opening cracks in the wood.
The vinification of red and white wines in oak vats offers numerous advantages.
The process of fermentation is facilitated by substances in the oak, while at the same time it goes on smoothly, without the wine being subjected to thermal shock.
Temperature control of the must or wine is made in the heart of the vat, so it is more effective, faster, and less energy consuming.
Because of the thermal inertness of oak, the extraction of phenolic substances and polysaccharides is greater but also more gentle, because extreme extraction methods are not required.
The thermal inertness of oak also aids in easier starting and finishing of the process of malolactic fermentation. The aromatic profile of wine made with malolactic fermentation in an oak vatis clearly superior to wine made where the process takes place in stainless steel tanks.
Also, no movement of the must is observed during storage of the wine in the vat, and the wine thus maintains its structure.
The result of the excellent work of the house of Grenier is the well-founded acceptance and confidence it has been accorded by world-renowned Domaines such as Romanée Conti in such well-known superior-quality regions as Vosne-Romanée, Gevrey-Chambertin, Montrachet, and Nuits St. George.