Concrete fermenters: from old school to New World
Wines & Vines
Nov, 2005 by Tim Teichgraeber
You see them when
you tour older wineries in poorer parts of Spain or Portugal--big
cement fermentation tanks, squarish in proportion and often open-topped
or covered with a slab of metal. To those of us accustomed to polished
stainless steel fermenters, they seem a throwback to the dark ages
of winemaking, days when barber-surgeons operated on people with
rusty tools and wines still had that elusive sense of place that can
only be imbued by distinctly local bacteria and blissful ignorance
of the niceties of microbiology and organic chemistry.
Many of the
old-school concrete fermenters that are still in use in the United
States and abroad have long since been coated in wax or some sort
of inert material to keep the wine from direct contact with the
concrete, often for reasons known precisely only to the ancestors
of the previous winemaker.
In the U.S., those old concrete tanks are
seldom seen on winery tours, and when they are, the official line
is generally, "They're
being phased out." But in similarly tech-savvy Australian wineries,
concrete tanks are still the preferred fermentation vessel for production
of many of the nation's classic wines: Hardy's Eileen Hardy Shiraz, Tyrell's
Vat 9 Shiraz and Torbreck RunRig Shiraz, to name but a few. Penfolds stopped
using them for Grange in 1973, but the lined concrete fermenters at
Penfolds' Magill Winery are still used for other wines.
By some reports,
square, open-top concrete fermenters are still widely used in Burgundy.
While they aren't necessarily fashionable throughout Bordeaux,
Christian Moueix and his head winemaker Jean-Claude Berrouet exclusively
employ modern concrete fermenters coated with an interior layer of
cement to make Chateau Petrus, Chateau Lafleur-Petrus and Chateau
Trotanoy in Pomerol.
For Moueix, concrete is more than just a sturdy
alternative to stainless steel and oak foudres--it's the material
of choice. Does concrete have unique properties that oak and stainless
steel lack? Some obviously believe that it does, and their success
has piqued the curiosity of some American winemakers. Viader and
Rudd Estate are two top-shelf Napa wineries that are taking a hard
look at concrete fermenters.
Cement Versus Concrete
Cement and concrete
are terms which are often used interchangeably, but the two materials
aren't identical.
Cement is generally composed of limestone, calcium,
silicon, iron and aluminum, plus other trace materials. It is cooked
in kilns to form marble-like "clinkers," then ground
into a powdery sand, to which gypsum is added. Mix it with a little water
and allow it to set, and you have nice hard cement.
Concrete is made from
crushed stone, rock and sand held together by cement. The cement
is only about 15% of the total mass of concrete. Concrete is stronger
and less porous than cement alone.
Advantages Of Concrete Fermenters
Advocates of concrete fermenters generally cite
concrete's ability to maintain a steady temperature during fermentation
as one if its chief benefits. Even wax- or steel-coated concrete tanks
share that temperature-stabilizing quality.
At the Bear Creek Winery
facility in Lodi, Calif., where Ironstone and Leaping Horse wines
are made, winemaker Craig Rous likes to use the 24,000 gallon epoxy-lined,
closed-top fermenters, supplemented with oak staves, to produce
his Chardonnay.
"They're
efficient, and not everyone ferments on oak. It gives you more integration
into the wine ... it softens the wine and adds butter and toffee character," Rous
says.
Christian Moueix also praises the temperature stability
of concrete fermenters, and believes that they produce clean-tasting
wines. "The
fermenters maintain a stable temperature throughout fermentation, which
is very beneficial during the end part of maceration," says Moueix,
whose fermenters range in size from 1,500 to 3,000 liters.
"You have
a very clean wine and you do not get the residual musty essence from
the barrels or cellar," says Moueix, who also believes that concrete
helps to combat reduction. "The disadvantage is that it is very hard
to keep it sanitary."
Like wood, concrete is also to some degree
permeable. Does that give concrete a micro-oxygenative effect that
helps to add texture? "It's definitely permeable, which makes it
very similar to wood--micro-ox is the new word for it," says Charles
Thomas, winemaker at Napa Valley's Rudd Estate. "Don't be surprised
if, after you put the first wine in there, the level goes down six inches."
Rudd
Estate and Viader are two notable Napa Valley wineries that have
been experimenting with concrete fermenters for the last couple of
years. In fact, they split the cost of shipping a container of fermenters
from a producer named Nomblot in Burgundy (cuves-a-vin.com). According
to Rudd Estate's Thomas, Nomblot was best known for producing concrete
mausoleums before it began producing concrete fermenters in quirky
sizes and shapes. Thomas currently has one pyramid-shaped open top
1,050-gallon fermenter. Delia Viader has several 600-gallon egg-shaped
fermenters, but says she may move to slightly larger ones with
the same shape. |