An amber wine from piwis

For the second part of my crazy #harvest2022 adventure, I headed to Austria to add another unusual wine to the Crazy Experimental Wines collection…

There’s a hammock chair on the balcony at BioWeingut Karl Renner with staggeringly beautiful views of Steiermark (Styria), rightly described as the “green heart of Austria”. The balcony, above the winery and near the kitchen of the family home, looks like a wonderful place to relax. Karl ‘Charly’ Renner, who took over the family wine business in 1997, comes here to think but he finds it difficult to relax. All he sees is the work that needs doing in the family’s organically-farmed vineyards.

BioWeingut Karl Renner has 6.5ha of vines, including about 0.9ha of rented vineyards and 1.8ha of new-generation piwi grape varieties. The piwis cause much less stress than his other white varieties (Sauvignon Blanc, Pinot Blanc, Morillon (Chardonnay), Muskateller, and Welschriesling).

In this “challenging vintage” – where there was much more disease pressure – he only sprayed the piwi vines once, with copper and sulphur, at the beginning of summer to prevent the fungus attacking older leaves. For one application on the piwis he used 1kg of Bordeaux mixture per hectare whereas for the conventional varieties he used 4kg.

Charly knows it’s been a tough year for the vines as he’s spotted some fungal diseases on two of the mildew-resistant piwis, Souvignier Gris and Chardonel. “This says the pressure was very high,” Charly states. For the first time, he may have lost 10% of these grapes to rot but he describes their performance in general as “super, wonderful”.

There is no sign of fungal diseases on the early-maturing Muscaris grapes (above). “Muscaris has very high resistance,” Charly confirms.

This is the grape I’ve come to harvest for my first piwi wine, as part of my crazy #harvest2022 adventure, which sees me making six wines in four countries in one vintage.

Like a growing number of winegrowers, I believe piwis – short for “pilzwiderstandsfähige” (resistant against fungal diseases) – are "the grapes of the future". They are resistant against the two main fungal threats in viticulture: Peronospora (downy mildew) and Oidium (powdery mildew). The modern generation of piwi varieties, such as Muscaris, Souvignier Gris and Chardonel, also have the potential to produce excellent wines. That’s what I’ve come to Styria to prove. Not only does Styria have amazing views, it also has the highest concentration of piwi vines (3% and growing).

“It’s the next step in organic farming,” Charly believes. “It’s the answer, so when you have the responsibility of a farm, of vineyards, and you have the chance to do it better than yesterday and you have the consciousness about that, you have to do it.

“Of course, on the other hand, it’s difficult to sell it because nobody knows about piwis. Nobody knows piwis exist.”

The Renners first planted piwis in 2011. These are the vines I’m helping to harvest, ten days earlier than last year.

The Muscaris grapes glisten in the morning sun (above). There are no signs of diseases and we’re only cutting out the berries that have been attacked by insects.

We fill six bins – one more than last year. I comment that this is impressive in a “challenging vintage” but Charly points out it probably has more to do with installing fencing to deter deer, escaping frost and hail, and the vines being more mature. “They are ready to give more grapes,” he states.

The vineyards below the balcony are growing varieties typical of Steiermark. But there is also some Souvignier Gris, planted in 2015, Chardonel (2016), and Blütenmuskateller (2020), which Karl plans to blend with the Muscaris in the future as they both have notes of citrus and nutmeg. Muscaris, Souvignier Gris and Blütenmuskateller are among the white grape varieties approved for use in Austrian Qualitätswein (quality wine).

My plan is to make a blend of early-maturing Muscaris and late-ripening Souvignier Gris, using a variety of winemaking techniques and featuring an element of skin contact.

The Muscaris, picked at 12.5% potential alcohol, is a crossing of Solaris and Muscat. It produces intensely scented wines, with nutmeg and citrus aromas and some smoky notes, and has a strong, full-bodied taste, with intense acidity.

Souvignier Gris is a pink-skinned grape from a crossing of Seyval Blanc and Zähringer, which is a crossing of Riesling and Traminer.

“We have to learn what is possible with these varieties,” Karl (above) says. His Piwi Amber is 75% Muscaris and 25% Souvignier Gris. His Muscaris varietal features 5-6% of amber wine, which gives it “a little more spine”.

The plan

The Muscaris is handpicked in two lots, three days apart. The first grapes are to be left on skins in a tank for about eight days. “My experience is, it’s better not to leave it for too long,” Charly advises. “Three or four weeks on the skins is too long because piwis have more tannins than conventional varieties.”

But it’s also dependent on the rest of the harvest and finding the time to remove the skins. “I’ll taste it when the fermentation slows and maybe we can leave it a few days more. It’s not a fixed idea.”

After crushing and destemming, most of the second picking goes into the press for a short maceration “to help the aromas”. Some of the second picking is also pumped into two new amphorae from The Hungarian Amphora Project. Once the fermentation with native yeasts finishes, the wines will be combined into one amphora.

The other part will go into a large oak barrel.

The Souvignier Gris, with its loose berries and thick skins, will stay out until late September or early October – usually being picked about ten days after the Renners’ red grape, Zweigelt.

“It’s still green,” Charly says, after tasting the grapes on his way back to Pössnitz from the Muscaris harvest. “Souvignier Gris could have a lot of sugar but also high acidity. When you wait you have potential alcohol of 14-14.5%, which we think is too high. This year I was thinking maybe I can mix it with a little Pinot Blanc and Chardonnay.”

In 2020 the Renners’ Souvignier Gris had 13.5% alcohol. Most went into used oak barrels and some went into a stainless-steel tank. The 2021 is still bubbling. “It tastes good at the moment, but the wine is always busy,” Charly comments.

We agree that we may have to age the wine longer than many whites, because of the extra disease-fighting tannins in the piwi varieties, especially if we blend a large proportion of the skin-contact element and choose to bottle it unfined and unfiltered with low levels of sulphur.

If we age the blend in a large barrel, Charly points out, it will have to be checked and topped up regularly.

I ask him to take care of all the components until I can return for the blending session – as I have two wines to make across the border, in Slovenia (a white and a red).

There’s just time to take in one more amazing view....

From the edge of the Muscaris vineyard I can see well into Slovenia, almost as far as its oldest city, Ptuj – my next destination. There, I plan to make a bone-dry Furmint, as it’s one of my favourite grapes, but this challenging vintage has taken its toll on this variety…

Back for the Souvignier Gris harvest

I return to Austria to complete the harvest for my modern amber wine – a blend of two disease-resistant grape varieties. I’ve come for the Souvignier Gris grapes…

“It’s been a good year for piwis,” Austrian winemaker Karl (‘Charly’) Renner declares as we wrap up #harvest2022 in Steiermark (Styria).

These disease-resistant varieties have come into their own in what winemakers in Central Europe keep telling me is a “strange”, “weird” or “extremely challenging” vintage, with the extremely hot and dry conditions of the summer followed by an extremely wet September. Charly says it’s been one of the toughest years for conventional grapes since the cool and wet 2014 and “you had to work hard” with them.

I’m back at BioWeingut Karl Renner, in southern Austria, to harvest the Souvignier Gris for my amber piwi blend. The late-ripening Souvignier Gris has good acidity and plenty of sugar (13.5% potential alcohol). I aim to blend it with the early-ripening Muscaris, picked two weeks ago and left on skins in two 350L amphorae. When this wine still had about 10-20g/L of sugar left, the skins were gently pressed and the wines were combined in a single amphora to complete their fermentation.

The Souvignier Gris is considered to be one of the best of the modern piwis – some say “the king of piwis”. It’s a pink-skinned grape with Seyval Blanc, Riesling and Traminer in its family tree.

We begin picking in fog. But, as the fog lifts, I can see the beauty of the valley stretching away from the steep slope where the 0.5ha of Souvignier Gris grows amid Steiermark’s more conventional Vitis vinifera varieties, such as Sauvignon Blanc and Chardonnay.

Harvesting on the one dry day in a very wet week, the advantages of the new generation of piwis (from the German for fungal resistant, “pilzwiderstandsfähige”) are obvious.

The Souvignier Gris grapes (above) look amazingly healthy after just one spray this year and are easy to see. Some of the leaves around the clusters were removed in the summer, but Souvignier Gris is less vigorous than the Muscaris growing on top of the hill. “The canopy is easier to manage,” Charly confirms. “Souvignier Gris, you need one hour to remove the leaves around the bunches, get the shoots in the wires – they are more erect than Muscaris. In the same size area, for Muscaris you need two or three hours.” Muscaris also produces a lot of suckers, and the vines need de-suckering a couple of times per season.

“Souvignier Gris – it’s not so much a jungle, it’s more free,” Charly adds.

About 10% has succumbed to botrytis, but these berries are now dry. The Muscaris grapes, picked two weeks earlier, were totally free of disease. Charly says Muscaris has “very high resistance”.

Picking piwis is a relatively quick affair. We only have to pick out the odd grape that has been attacked by an insect.

It takes our small team of five pickers from Slovenia plus the Renner family (Charly, wife Maria, father Erwin, mother Walpurga) and me four hours to collect six bin-loads. The one downside of the small berries and thick skins is the lower yield from each bunch. Charly reckons each bin will produce about 220L of wine – whereas for other varieties it would be more like 250-280L. In 2021, five bins of Souvignier Gris filled five barriques.

The crushed and destemmed grapes are destined for a mixture of amphora and stainless steel for fermenting and will be aged in amphora and oak barriques.

In 2021, BioWeingut Karl Renner’s Souvignier Gris spent three months on full skins and until August on 20-30% skins, when it was given a gentle squeeze in the pneumatic press. The colour is a golden yellow and there is no hint of the ‘gris’ colour in the wine, despite this extended period of maceration.

The plan is to use several components of Souvignier Gris in the final blend – some with 72 hours’ skin contact in the press, some with two- or three-weeks’ skin contact, and some with six months or longer.

“Souvignier Gris is a variety that can stay a long time on the skins,” Charly confirms. “Now we know six months is not too much.”

He adds: “What we have to do is learn how to handle it and which is the right way to make the wine. Skin contact? Yes. How long? Which vessel?”

Of all the plans for my crazy #harvest2022 adventure – making six wines in four countries in one vintage – this piwi project was the only one that was never in doubt; the only one I haven’t had to amend because of this “challenging vintage”.

In between the two piwi harvests, I went to the Haloze hills in Slovenia to make a white wine with a talented young winemaker, Michael Gross of Vino Gross (above). I wanted to make a skin-contact Furmint with him but when I arrived and saw the state of some bought-in Šipon/Furmint, we agreed it wouldn’t be wise to macerate these grapes. Instead, we are making an unusual white blend – a co-fermentation of free-run Laški rizling (Welschriesling) and whole Traminec berries. More about this wine here (link to come).

My plans to make a Kadarka (a light and spicy red wine) with three producers in different regions of Hungary, using three different technologies (oak, steel and Flexcube), has also been dampened by the rain. While I’m picking the piwi, one of the Kadarka producers calls to say they won’t have enough good quality grapes for my project…

“Everything is out of balance,” Charly Renner observes, as we lunch with the picking team, overlooking the freshly-plucked vines. He’s talking about the weather in 2022.

I nod in agreement and marvel at the organic pink grapes in the bins (above), heading to BioWeingut Karl Renner’s small winery in Pössnitz. They look glorious. They look like the future to me. 2022 has proven they can cope with the weirdest and strangest growing conditions.

The last bin heading off is from the top rows of young vines, which replaced a piwi that didn’t work here: Cabernet Jura. Charly shows me the one Cabernet Jura vine that he didn’t replace (above). The red grapes are not worth picking. “It’s not so resistant. Very thin skin and early ripening,” Charly points out, before making a general observation about piwis and a plus-point for Souvignier Gris: “The disadvantage with piwis is: some of them are too early with the background of climate change. Souvignier Gris is the opposite – there is always enough acidity. First, I thought you have too much sugar and acidity but after two or three years I realise you need this acidity. It’s the spine of the wine.”

It will be the spine of my amber piwi creation, which is due to be Crazy Experimental Wines’ second or third release.