Low Intervention Does Not Have to Mean Funky

The tagline for this class was: from healthy soils to healthy grapes to healthy wine. The three flights followed that order, and the argument underneath it is that low intervention is a farming and cellar practice, not a flavour.

Two Axes

The framework I use is a grid with two questions on it, because conflating them is where most of the confusion about natural wine comes from.

The first question is the agriculture: conventional, organic or biodynamic. When I say conventional I mean pesticides, herbicides and dead soil, not a style of wine, and that distinction matters because the more doctrinaire end of the natural wine scene uses the word as an insult for anything it dislikes.

The second question is the style of the wine: clean, spontaneous, or funky. A wine can be impeccably farmed and taste completely clean, like a Riesling or a Pinot Blanc, with no volatile acidity and no horse stable anywhere near it.

Every producer in this class was organic or biodynamic. Not one was conventional. In style, all but one sat in the spontaneous band rather than the funky one.

The German Associations, Briefly

Since most of the line-up was German, the labels need explaining. Demeter is international and biodynamic, going back to Steiner and Maria Thun, and it is a rulebook: cultured yeast is forbidden, so asking a Demeter grower whether they ferment spontaneously is a pointless question. Ecovin is a German organic association of around 130 members, which allows cultured yeast and takes financial sustainability seriously; many members use biodynamic methods where they suit. Bioland is the least restrictive of the three.

Flight One: Healthy Soils

The first wine was the Riesling Kieselsandstein 2023 from VDP.Weingut Beurer in Württemberg. Fifteen hectares, Demeter, Respekt-BIODYN, Ecovin and VDP all at once, which is a rare combination. It is as clean as Riesling gets, with the ripeness of a moderate climate and a clear expression of its site, and it has the creamy edge that a partial, uncontrolled malolactic gives. That lack of control is the point: nobody stopped it with sulphur and nobody pushed it along.

The second was from Weingut Hemer in Rheinhessen, Ecovin, organic since 2003, 55 hectares, and here the honest answer is instructive. About 70 per cent of their wines are fermented spontaneously and about 30 per cent with cultured yeast. At this scale a contract with a national organic retail chain is a large part of the payroll, and one failed fermentation could halve what they can deliver. Sometimes a controlled fermentation is the responsible decision.

The wine, raised in a 500 litre Stockinger barrel, was cleaner and fresher than the first, more herbal and spicier with a ginger note, and it made the point about terroir by tasting nothing like the Württemberg wine.

The reason for talking about soil at all is something I saw in their vineyards. Hemer's rows on one side, a conventional neighbour's on the other, in midsummer. On their side, green, flowering and crawling with life: fourteen or fifteen species visible within ten seconds. One step across the line, nothing at all. Not a single insect wanted to be there.

The third was from the Demeter estate Fluhr-Eller, 36 hectares in Rheinhessen: round, ripe and clearly malolactic, and, unusually for a wine with that texture, entirely from stainless steel. Which is the argument. We associate steel with lean, acid driven wine, and usually that leanness comes from cultured yeast and a well-timed sulphur addition. Allow the microbiology to run and a steel tank can produce something else entirely.

Why Bats, and Why Guinea Pigs

The case for Demeter is easier to make through practical examples than through the spiritual ones.

Trees in a vineyard: bats navigate by echolocation, and the echo needs something to bounce off. More trees and forest structure means more bats, and bats eat insects.

Birds: growers spend a great deal of effort scaring them off with bangers and rattles. A Danish couple put up a tall pole with a nest box on it and a pair of falcons moved in the next day. Most birds keep well away from a bird of prey.

And a Swiss Demeter grower who keeps guinea pigs instead of the fashionable Ouessant sheep. They are too small to reach the grapes, and their short legs break up the ground and collapse the mouse tunnels.

None of that is esoteric. It is working with the system rather than against it.

Flight Two: Healthy Grapes

The threats are familiar: downy and powdery mildew, botrytis when it is not wanted, black rot, spotted wing drosophila. And then the climate, which in recent vintages has meant spring frost, severe in Poland among other places, overripeness in hot years, drought stress, and rain that arrives too heavily to be absorbed.

Soil work mitigates the last of those directly. Stephan Steinmetz on the Mosel filmed a heavy rainfall event across three neighbouring vineyards: on the conventional one the water ran straight down the road, on the organic one less so, and on his own, which sits highest and should therefore have shed the most, essentially none, because the ground could take it.

The wine for this flight was a blend of Sauvignon Gris and Johanniter from Benjamin Lanz at Lake Constance, eight hectares, everything spontaneous, organic but not certified. The site is a case study in disease pressure: Alpine air, a very large body of water, and a warm climate zone. Resistant varieties make obvious sense there.

The wine also makes a point about what PIWIs taste like. It is subtle and restrained, and blind it would not be the first guess. The varieties are crossings, usually of a Vitis vinifera parent with material carrying genes from Vitis amurensis for frost hardiness or from American species for mildew resistance, the diseases having come from America in the first place.

The number that matters is the spraying. Riesling in the Pfalz can need twelve to fourteen passes a year. Souvignier Gris needs two or three. That is 70 to 80 per cent less time, money and tractor weight on the soil.

Organic Where Possible

The last three producers were all from the Mosel, and all of them describe themselves as organic where possible rather than certified. On the steepest terraces, with high disease pressure, extreme vintage variation and holdings of one to three hectares, certification can be the thing that makes a business unviable.

Julien Renard farms 2.5 hectares, a Belgian who ended up on the Mosel, uncertified by choice because the terraces cannot be mechanised. Two and a half to three and a half hectares is roughly what one person can work alone, pruning, picking and cellar included; above that you need staff.

His Riesling 2024 was the only genuinely funky wine of the day, and it was chosen for that. There is a touch of volatile acidity on the nose, deliberately. What makes it work is that the palate is clean: mineral, crisp, earthy and herbal, with the volatility gone entirely. That, for me, is the line between a stylistic decision and a fault.

Flight Three: Time

Before science, a winemaker had two tools. The first was a prayer that the vintage and the cellar would behave, at a time when the bottles exploding in spring were attributed to demons. The second was time, because there was no temperature control and nothing to correct a wine with. That is still the method here.

Maximilian Knebel farms half a hectare in Winningen alongside a full-time job in the regional tax administration, handling winemakers' tax affairs. The Winninger Uhlen Riesling 2022, two years in oak, was four years old in the glass and the best argument of the afternoon. Everything in it has arrived in the same place: the acidity, the backbone, a light malolactic touch and a faint rusticity from the wood.

Riesling is not straightforward to follow. It is joyful for two or three years, awkward for several after that, and only opens out again at seven or eight, and then only if it has aged properly: ginger, hay and nuts rather than petrol.

How long these processes can take is worth stating. Kai Schätzel said in a panel at the VDP Weinbörse that a hardcore low intervention Riesling fermentation can run for up to four years. Michał at Winnica Jakubów told me about a barrel whose fermentation stopped, which he then forgot about, and which had started again by itself when he found it eighteen months later.

The last wine was from Tim Röttgerding, one hectare on the side of his work at Heymann-Löwenstein, where he learned from Reinhard Löwenstein. A 2024, in 500 litre oak, spontaneous, nothing added. The larger format is the usual choice in this style: it stabilises the process and gives the microbiology room to work with a little oxygen.

Next to the 2022 it is visibly unfinished. It is fresh and mineral and acid driven with some creaminess from the wood, shooting in several directions at once. It is a pleasure to drink with seafood, and it is two years away from being what the Knebel is now.

Which is the conclusion. If you add nothing to what is a biological and chemical process of considerable complexity, the only way to finish the wine is to wait.

This master class was held at the first Cool Climate Wine Summit in Warsaw. Glasses by Stölzle Lausitz.