This may sound like a slightly peculiar theme for a wine article but it’s much more logical when you know the context. Modern day winemaking may have the added benefit of technology for control, precision and efficiency but some of the materials used in the process date back decades and, in some cases, centuries. We’re talking specifically about the types of vessels used to ferment, mature and store wines in.
A snapshot of winemaking through the ages
We know, from hard evidence unearthed in Georgia in the Caucasus, that turning grape juice into wine dates back at least 8,000 years. Archaeologists dug up ancient qvevris (types of earthenware vessels) that would have been buried underground with crushed grapes inside. The grape juice would have fermented naturally over time and converted into wine.
Ancient art from burial sites and ruins as well as the qvevris themselves showed depictions of grapes, vines and people drinking which further supports Georgia’s claim as the natural birthplace of wine. Clay amphorae were used in winemaking by the ancient Greeks and then more commercially by the Romans and today, we’ve come full circle as they’ve become popular again among artisan and low-intervention winemakers.
The early use of wood in wine production, or more specifically storage, is credited to the ancient Mesopotamians. We’re going back at least 2,500 years and the preferred wood at the time was palm but this wasn’t particularly pliable. It’s thought that the ancient Celts in Gaul invented the wooden barrel around 300BC, most likely from oak. The enterprising Romans perpetuated its use and oak casks are still in great demand today for all quality wines.
Fast forward to the 19th century and concrete vats were installed throughout larger estates and co-operative wine cellars particularly in Argentina and across eastern Europe and Soviet states as they were large and relatively cheap. Some of these old vats are still in use today, particularly in Argentina for their Malbec.
In the early 1960s, the first stainless steel fermenters were introduced into wineries such as the illustrious Château Haut-Brion, offering a level of hygiene and controllability that couldn’t be so easily replicated with other more traditional materials. But it wasn’t just the white wines that benefited, many top red wine producers like Angelo Gaja in Piedmont have sworn by the use of stainless steel fermentation tanks since he installed them in the early 70s for his stunning Barbarescos.
Some prime examples of each
Nothing beats putting theory into practise and these next three wines are great examples to demonstrate their respective fermentation vessels.
First up we’re starting with concrete fermentation and this means a trip to Argentina. Malbec seems to have a good affinity with concrete and the Doña Paula Estate Malbec from the Uco Valley is a textbook example. There’s a liveliness of aroma and fruit flavour that’s highly moreish and the tannins are noticeably rounded delivering a great wine experience for the money.
Down to the southern French coast between Montpellier and Narbonne, lies the small wine producing region responsible for Picpoul de Pinet. This historic white wine has gained huge popularity here within the past 5-10 years and is absolutely ideal for the local oysters that are pulled out of the Étang de Thau. Fermented at relatively cool temperatures, this wine is crisp, delicately fruity and has a touch of salinity that only stainless steel can preserve to this degree.
Finally, zipping over to Western Australia and the relatively cool climate styles of reds that they can produce. Larry Cherubino’s ‘Middle of Everywhere’ Shiraz is pure, intense and spicy and requires time to soften and mellow and oak casks are the best receptacle to enable this. Spending 6-8 months in new and one-year-old barrels is just the right amount of time to help the wine find its ideal balance and structure.
The pros and cons of concrete
It’s important not to confuse or interchange concrete with cement as these are two very different substances. I won’t go into the technicalities of what those differences are but safe to say that cement is a component of concrete, normally around 15% by mass, and is more porous which is why a lot of the old industrial-sized tanks were constructed out of concrete.
We already know that concrete is relatively cheap, although the modern-day concrete fermenters that come in various shapes and sizes, like eggs and truncated pyramids, are not cheap and are therefore being used for more premium wines as a result.
Another benefit of concrete fermenters is their ability to maintain a consistent temperature as the wines ferment. This makes for a more stable fermentation process which many advocates believe leads to cleaner tasting wines with better definition.
Being a little porous like wood means that wines receive micro-oxygenation during their fermentation, which essentially means a very small, controlled amount of contact with air. This helps the wine to develop its aromatic profile and also helps rid itself of the more volatile sulphur compounds that can result in faults like reduction. (More on this under stainless steel below).
The downside of concrete, especially the large square-shaped tanks of old is that they’re hard to clean and so maintaining good hygiene, which is absolutely critical, can be very tricky.
The pros and cons of stainless steel
Perhaps the greatest advantage of using stainless steel for fermenting wine is that the temperature can be regulated through the use of cooling jackets, preventing the wine from being spoilt by excessive heat. Red wines tend to reach higher fermentation temperatures than white wines so certainly for young, vibrant reds, stainless steel will be the vessel of choice.
Another advantage is that it’s comparatively cheaper than wooden vats so for lower-priced, higher production wines, it’s ideal.
A further benefit is that because they can be made air-tight, you can preserve the delicate primary aromas of young, fresh white and red wines that are intended for early drinking.
This, however, can also be a negative as you run the risk of reduction, which is a fault attributed to wines that haven’t received enough oxygen during the winemaking process and can give off a whiff of burnt match or at worst, rotten eggs/stinky drains.
The pros and cons of oak
Just like concrete, oak is a porous material so wines not only evaporate over time, but they also micro-oxygenate too. This especially helps to stabilise the colour in red wines as well as form longer-chain tannins. This basically means that the tannins are rounder and less astringent so that the wine has a better mouthfeel.
Oak can also add to the flavour profile of some whites and reds, which adds complexity with anything from vanilla and butterscotch to hazelnut and Asian spice flavours. It can also build a greater tannin structure which gives the wine a better ageing ability, particularly when brand new oak is used.
Oak also acts as a natural antiseptic and so requires less use of sulphur dioxide for stability. It also helps to clarify the wines naturally so it’s common to see artisan producers bottling their wines straight from barrel without the need to filter or fine.
The main downsides are cost, which is comparatively high, especially if you start investing in large oak foudres (up to 15,000 litres) or fermentation vessels. The other downside is over use. Too much new oak on a delicate wine will overpower it and make it unbalanced and difficult to drink. We’ve all experienced those heavily oaked Chardonnays back in the 90s and early 00s!
As wine styles continue to evolve, the range of equipment available evolves and grows in tandem but for now, the ancient materials of concrete, steel and timber, and increasingly clay, continue to be the materials of choice.