Jamie Goode: Old vines – do they always make better wine?

‘Imitation is the sincerest sign of flattery’ says the first half of a famous quote from Oscar Wilde. If this were true (and the second half of the quote suggests that it isn’t) then South Africa’s Old Vine Project should be very flattered by the emergence of look-alike ventures aiming to promote (and benefit from) the current interest in old vines. But what is it that makes old vines so appealing from a scientific viewpoint? Is the quality of wines made from old vines directly related to the fact that the vines are old, or is it a correlation rather than causation? And are we in danger of tripping out on the concept, playing into the hands of marketeers?

South Africa has really led the way in championing old vineyards. Back in 2002, renowned viticulturist Rosa Kruger began cataloguing all the old vineyards in the western Cape. Initially, this was a painfully time-consuming project that involved a lot of driving around. But the Old Vine Project took a step forward when in 2014 SAWIS – the official body that has kept records of all registered vineyards since 1900 – agreed to let her have the information, on the condition that she shouldn’t publish any details without the permission of the owners of each vineyard. After calling up farmers with the aid of a team of volunteers, she then launched the I Am Old website, which gave the details and contacts of all vineyards over 35 years.  In 2016, Johann Rupert provided the funding that enabled the Old Vine Project to take the next step forward. Two important people were hired. Viticultural consultant Jaco Englebrecht was recruited to help growers to restore old vineyards, which, with a bit of skilled attention can be made to produce yields that are high enough to make them viable. And André Morgenthal, who for 15 years was marketing manager with Wines of South Africa, came on board to run the project. Jaco has since moved on to run his own vineyard consultancy, but André is still there.

The goal of the Old Vine Project is to preserve this heritage of old vines by making sure they are economically viable. Often the vineyards produce less as they age, and if winegrowers aren’t paying farmers a premium for them, they can become uneconomic and liable for uprooting. Also, the fruit from many of them is disappearing into large blends, and so they aren’t being prized for their quality. Since 2018 there has been an Old Vine seal that can go on the neck of a bottle made from grapes from Certified Heritage Vineyards, with the year they were planted marked on it. This is creating an economic incentive to value old vines more highly and thus ensure their survival. Currently 85% of the old vineyards are tied up in the co-op system, and André has been trying to convince them to make wines separately from these old vines. ‘We have seven co-op members now,’ he says, ‘and it has totally changed their business model. The grapes that were going into 70 Rand bottles are now selling as premium old vine Chenin at 300 Rand!’ Overall, there are 4292 hectares of vines that are aged 35 and over, which is just under 5% of the vine area in the country. Half of this area is Chenin Blanc, but there are also another 38 varieties. But one of the other aims of the project is to give greater protection of vineyards currently 20–30 years old, which if nurtured, will soon join the band of old vineyards. And one of the goals of the project is to care for the vineyards that will be the old vineyards of tomorrow. Rosa and André have been working with the Vititech in Paarl to create a nursery of the best heritage selections. ‘We have managed to save some of this material and clean it up,’ says André . ‘We are not only looking after old vines, but we are looking after our future as well: you have to plant to grow old.’

The planting material in the 1970s and 1980s was very poor, and most of these vineyards – especially the reds -couldn’t last longer than 20 years. ‘This is why we have hardly any old red vineyards,’ says Andre, ‘especially Cabernet and Shiraz.’ Most old vineyards are Chenin Blanc, followed a lot further back by Sauvignon, Colombar, Muscat, Pinotage and Cinsault. As of 2022 there were 10 blocks that were centenarian. Back in 2018 there were 48 members of the Old Vine Project; now there are 130. And there are more than 250 wines bottled each year with the heritage seal.

So what’s the science? Vines take a while to get into their stride. They usually throw their first crop in what’s called third leaf: the third year after planting. [The grapes from these baby vines are often surprisingly good.] Then the young vine enters something of a sullen teenage spell. In famous vineyards, such as Burgundy Grand Cru sites, the grapes will usually be declassified until the vine really begins to perform. When is this? It depends on the site, but most winegrowers seem to think that it’s around age 10 that vines seem to come into their own. Wines from young vines are often fruity and pretty, but lack substance. After about 10 years, you begin to taste the site as much as the variety. And things generally improve from here. A vine is properly mature at age 20. Past this, and yields can begin to dip a bit. Many commercial vineyards, where the goal is good quantity (if acceptable quality is achieved), are replanted when they get to their mid-20s. The economics of these vineyards doesn’t work with low yields. And there might be problems with viruses or trunk disease, too.

Why is it that the grapes from old vines are so desirable? It’s partly a question of the vine getting into balance. For grapes to be top quality, the vine needs to switch from focusing on growing leaves to ripening fruit at the right stage in the growing season. An old vine grows enough leaves to ripen the grapes, but not too many, and seems to focus on the moderate yield of grapes that it produces in a way that concentrates the flavour and gets them appropriately ripe.

An old vine is also likely to have developed an extensive root system that thoroughly interrogates the soil. This could be helpful for grape quality. And the larger trunk and root system acts as a carbohydrate reserve that helps get the vine going early on in the spring. Early in the season, the vines rely on these reserves to get going, and grow leaves, and it takes quite a while until these leaves are generating more carbohydrates than their growth is requiring. So older vines have an advantage here because of their reserve capacity.

There’s the intriguing idea that old vines may have adapted to their environment through a process known as epigenetics. This is complex to explain, but sometimes there are changes to the non-DNA part of the genome that can affect gene expression, and these can be induced by the environment. Research on epigenetics in vines is still at an early stage, but it would be interesting if old vines had somehow adapted to their environment through these epigenetic modifications. But taking cuttings seems to result in epigenetic reprogramming, and this adaptation isn’t passed on.

Perhaps, also, there’s a confounding factor: if a vineyard is making amazing wine, it’s unlikely to be ripped out or replanted. By this logic, the only vineyards where growers tolerate the economic loss of low yields are very good ones. This could explain part of the ‘benefit’ of old vines: they tend to be found in very good sites.

Then there’s the teenage hypothesis. The first crop or two from a new vineyard is often of very high quality. That’s because there’s a nice balance between foliage and crop load. Then, as the vine gets going it enters its teenage years, and starts producing a big canopy. It takes a lot of viticultural work – and smart work – to get the balance between canopy (the leaves and shoots) and fruit (the bunches of grapes) right. Then, as the vine enters adulthood and leaves its teenage ways behind, the balance comes back. It throws an appropriate crop (of course, depending on it being a good site) and the canopy grows enough to provide the photosynthesis necessary to ripen the grapes, but not too much that there’s excessive shading and a refusal to stop growing. In vigorous vineyard where the canopy grows too much, winegrowers must pass through and trim it. This can encourage the growth of lateral buds which end up shading fruit. The vine really needs to stop growing more leaves at the right time so it can focus on ripening fruit: this is what old vines often end up doing, and could be one reason why they are prized.

Another reason for the resilience and good performance of an old vineyard is an idea I’ve not seen applied to vineyards before, but which I’ve taken from studies of old growth forests, and it concerns the common mycelial network. Far from soils just being a medium for plants to grow in, there is now a realization that they are living. And this ecosystem is complex, and vital to how plants grow. Mycorrhizae are networks of fungi that live in association with plant roots – around 80% of plants have these symbiotic associations. They vastly expand the reach of plant roots, and the plants feed them with their photosynthates in exchange for the extended reach they get exploring the soil for nutrients. It has been shown, though, that these mycelial networks actually connect plants – even plants of different species. There is a sharing of resources, and also a sharing of alarm signals from attack by diseases or herbivores, allowing neighbours to switch on defences. Suzanne Simard from the University of British Columbia, Canada, made this wood wide web of common mycelial networks famous, and there’s every reason to suspect that it might also operate in established vineyards. We need more research on this. It’s also a good reason to care about soil health (cue regenerative viticulture). Old vines are rightly prized. But ultimately, once a vine has passed its vigorous youth and has established a decent root system, the main factor is place. Some terroirs are simply better than others. Give me a 15-year-old vine on a great site versus a 50-year-old vine on the fertile valley floor any day. The discussion of the science of old vines continues.

• Jamie Goode is a London-based wine writer, lecturer, wine judge and book author. With a PhD in plant biology, he worked as a science editor, before starting wineanorak.com, one of the world’s most popular wine websites.