Nicholas Livingston maakt op Trout Brook Vineyard een mousserende wijn volgens de méthode traditionelle. Op uitnodiging schreef hij een persoonlijk verslag van het ingewikkelde proces om een lekkere bubbelwijn te maken.
Étoile du Nord
Imagine a climate so cold few grapes ripen and that those which somehow can thrive at these extreme reaches retain a blindingly bright acidity. Think of a continental climate of four seasons, of balmy summers countered by winters so cold that yeasts hibernate into a torpid inactivity. Winemakers with deep cellars might find their wines sparkle come springtime and why? These drowsy yeasts are tucked to bed like arctic explorers who succumb to hypothermia as the mercury falls –only these yeasts are even more resilient and wake come springtime when they realize there are still ample sugars upon which to feast. These revels rouse among other things carbon dioxide but with no way to escape a sealed bottle these bubbles have no place to go but into the wine itself for months or years until the cork is drawn and releases a cascade of texture, fragrance, and life.
La Champagne is such a place and for which her sparkling wines beguile and have already earned their hallowed place among household names. The North of the United States is also such a place but its wines remain unsung heroes whose deeds are not yet proven and who have yet to reach your lips.
Welcome to Wisconsin –a land of mixed forests, farmland, lakes, rivers and streams. At Trout Brook Vineyard we have on hand nearly 3,600 vines spread over 12 acres and counting –because Ernst has us forever hand planting more blocks of rows each year. These quilt the slopes of his paradise atop the upper Saint Croix River Valley –hills comprised of alluvium and clay not unlike the Marne River that flows through Epernay at the heart of Champagne. Despite all its steady trout streams and woods rich with forage, fauna and so many other natural charms we simply cannot grow the Vitus vinifera of Pinot Meunier, Chardonnay or Pinot Noir traditionally planted to Champagne. Instead like so many in America we are using hybrids of the new and old world that prove essential in this landscape.
Nine varieties of wine grapes have taken root at Trout Brook. In the years since 1993 they have become so familiar to us and yet remain little known outside northern climes. Their family trees reveal an intermarriage of the European Vitis vinifera and the native American Vitis varieties most notably labrusca and riparia –whose name tips its hat to the rivers along which they thrive. Our indigenous stock is essential for the desirable vinifera traits to survive to express themselves at all but unless handled delicately, these riparian traits can express a ferocious foxy character which comes from the skins of the grapes themselves.
‘Our first trial – thanks to beginners luck – turned out a balanced, effervescent sparkling wine.’
Considering our ingredients we find the methods of Champagne suit us well. Between their propensity toward crisp acidity and the nature of their foxy skins, our hybrids make natural candidates for sparkling wine because the lifted acid lends structure and the clusters are immediately pressed off their skins when they come in from the vineyard so the foxy notes are kept out. Couple these with a cool climate which limits brix, or sugar levels, at harvest and we are sure to preserve low alcohols in the base wine which ultimately ferment a second time to summon the sparkle raising the alcohol content another 1.5%. It seems the stars in the sky and the land beneath our feet are charting our course and so we listen.
Our first trial with a blend of local white grapes was in 2011 and thanks to beginners luck it turned out a balanced, effervescent sparkling wine redolent of apricots and possessing a crisp and creamy texture. The following year we tried this method with Chardonnay fruit which we trucked in from California just to see how it compared. Coming online after years in the coldest part of the cellar it is now proving almost champenoise at least in terms of its ready, steady bead, mineral driven stone fruit and its pastry and biscuit notes –perhaps from a portion of the cuvée aging in French oak casks and then perhaps for its long rest on its lees .
In 2013 we made another local sparkling wine this time a varietal bottling made exclusively from Frontenac Gris which is resting in bottle for another year before dégorgement, liqueur d’expedition and finishing. Boosted by initial success and now with a real taste for it we decided to ramp up our trials in 2014 into five different batches of varietal sparkling wine made exclusively from Prairie Star what would be a Blanc de Blancs or white wine from white grapes. While this sparkling wine method is more involved than any other sort of wine we have made it is proving worthwhile at every step as outlined in broad brush below.
Harvest, pressing, primary fermentation
Thanks to Ernst’s assiduity in the vineyard each year and every year along with the cooperative weather of the vintage, the fruit came in to the winery in great shape, roughly 18.5 brix which translates to a finished base wine of 10.5% alcohol by volume. Once in the winery we immediately pressed all grape clusters thereby eliminating skin contact during fermentation. We allowed this coarse pressing to settle and then siphoned the cleared wine off the top of the sediment. Once transferred into fresh fermenting tanks we pitched vigorous yeasts chosen for their thorough ferments –yeasts that hunt down every gram of sugar leaving our base wine bone dry by design.
Because the acidity is so high we put our wines through cold stabilization, a process in which we leave tanks out in the cold of winter when the days are far below freezing. At such temperatures the tartaric acids in solution precipitate and fall out of the wine like diamonds at the bottom of the tank. We rack this still wine off these crystals into fresh vessels and after a brief rest ranging from a few months to nearly a year we blend the batches that might complement one another and then the magic begins.
Prise de mousse | Secondary fermentation
In order for this still wine to sparkle we have to feed it just enough liqueur de tirage, vinous sugar syrup, for its second fermentation to reach 5 to 6 atmospheres or pressures of 70 to 90 pounds per square inch. Any more and even these sturdiest of bottles will burst. Any less and its mousse will lack the nature of the finest wines of Champagne. We concoct a simple-syrup gently simmering a little of our base wine with an organic evaporated cane sugar. The amount is determined by each batch but the final admixture should measure 22 to 26 grams of sugar per liter. Once cooled we stir this syrup into the wine with added yeasts, yeast nutrients and a little riddling aid to help us later at remuage (riddling). We give the wine a night or so to proof the yeasts’ viability expressed through active bubbling through airlocks. Then this quickly goes into extremely solid bottles which we seal under special crown caps affixed with bidules –little cups inside the cap that collect the yeast at riddling.
Maturation on lees
Now comes the waiting game proving patience a virtue. Freshly capped bottles spend a couple weeks in the warmer parts of the cellar. This makes sure the caps have sealed and to give the yeasts a little head start before all are transferred to the coldest corners of the cellar. Shaken and then stacked sur latte, or flat on their sides, these bottles will rest from nine months to three years or even more before they progress further in this transformation.
During this time the yeasts slowly work through all the added cane sugar. Once there is no more to be had they go dormant at first. With nothing to rouse them they actually break down in a process called autolysis where yeasts self-digest by their own enzymes into proteins that help transmute mere sparkling wine into something beyond. These lees settle to the bottom edge of the bottle. Immensely special, this is one of the chief characteristics that set Champagne and all who imitate champagne apart from the simple, fruity sparkling alternatives. All wines require yeast to convert sugars to alcohol but few incorporate into the wine the very carbon dioxide they give off and fewer still invoke the yeast’s scents and flavors by autolysis. This is alchemy.
Remuage | Riddling process
After months and months or even years later each bottle contains up to 250 million bubbles of integrated carbon dioxide and over time the wine has taken on some of those desirable yeasty notes of brioche, pastry, biscuits, even nuttiness along with floral notes unattainable otherwise. Our challenge now is to somehow remove the lees from the bottles so that every glass is crystal clear of any sediment.
At this stage we delicately move these bottles from their beds sur latte to our pupitre or riddling rack. Picture a lean-to or an A-frame with each side made of sturdy planks of heavy white oak with 60 small holes cut at an angle. Into these we put the necks of each bottle headfirst so they begin parallel to the ground in the position they have rested. Over the course of three to five weeks we make a daily effort to give each bottle a slight snapping twist, first this way and then that each time raising each bottle further on its head until all the lees are settled against the crown cap. Once ready these bottles are stored in cases on their heads and are ready for disgorging.
Dégorgement | Disgorgement
With all the lees riddled to their very caps we are especially careful to remove them so as not to foul the wine with cloudy sediment. This also preserves as much effervescence as possible. Chilling the wine helps to reduce pressure and therefore keeps as much carbon dioxide in solution as possible. While bottles are still on their heads we chill them down for an hour or two. This we do outdoors during midwinter when nature is generous with temperatures far below zero. When earnest and doing this in the summer months, we put these bottles in a chest freezer. Either way before you know it that centimeter of yeast against the crown cap freezes into a little plug of ice.
Wearing aprons and other protective gear we use a clé de dégorgement, or disgorging key, which pries the crown cap away from a person instead of in their face like most bottle openers. With this we can pull off crown caps with dispatch, launch the ice plugs of lees away from us and quickly stopper the mouth of each bottle with a thumb until they calm.
Dosage | Finishing sugar
Moving quickly after disgorging we add to each bottle the liqueur d’expédition, a solution of cane sugar and wine. We are sure to chill this to the same temperature as our sparkling wine to reduce foaming. We quickly top up any remaining headspace with bone dry sparkling wine from the same chilled batch. Aiming to produce a sparkling wine at a Brut dryness, which measures under 15 grams per liter of sugar, we calculate for 9 g/l to keep it fresh and dry.
Bottles are then finished under sparkling wine corks. Wire bales then muzzle these down with their lowest wire caught under the bottom lip of the bottle to ensure a reliable seal. It is essential to contain that which would otherwise be the weakest point of an explosive 5 to 6 atmospheres of pressure –three times the pressure of a car tire. If permitted to soar unchecked a champagne cork can reach what has proven a lethal 25 miles an hour (40 km/h) so these need to be snug. Winemakers must take every precaution for one’s own and others’ safety.
‘The vine to glass method of sparkling wine illustrates just how many steps one must take to breathe life to still wine.’
Following dosage bottles rest for three to six months before any corks are drawn to overcome the violent shock of chilling, disgorging and the fresh addition of liqueur d’expédition. During this period of cellar maturation, carbon dioxide settles back into the wine. The sugars can incorporate into the profile. The wine comes into its own –ready to grace the table at long last.
Working with our ingredients
No doubt the most demanding and time consuming wine we have made, this vine to glass method of sparkling wine illustrates just how many steps one must take to breathe life to still wine. In doing so one runs greater risks. One spends more time hard at work to see each additional step through to the end but the rewards are great and make it all worthwhile. We are tuning into everything around us; our terroir which combines our unique grape varieties, our soils, their aspect and the influence upon them by our climate and each year’s weather; our love for the grower champagnes of the récoltant manipulants by whom we are inspired; and our insatiable appetite for moving and memorable sparkling wines which insist upon us that we fine tune these methods to craft the finest wines possible in this northerly landscape.
We have really only begun listening but we have started and through ongoing trials we will find which methods resonate best. From pressing whole clusters at harvest at different pressures to exploring varied yeast selections, from cold stabilizing at various temperatures for different durations to using every type of sugar at prise de mousse and dosage, from investigating different temperatures while the wines rest sur latte to exploring various riddling methods, from comparing dégorgement a la volée versus dégorgement a la glace to fine tuning our liqueur d’expedition we are growing from mere babes in the woods feeling our way through the dark to prescient vignerons –winegrowers who make their wines in both sun soaked vineyards and cellars so cold that our wines sparkle like the stars that guide us.