The Moscato d’Asti ferment – “Bubble bubble boil and trouble”

Have you ever thought about the risk involved in making a joyful beverage like Moscato d’Asti? Surprisingly for such an easy-drinking wine, it is one with a fair amount of winemaking technique involved. Ladies and gentlemen, Moscato d’Asti is not your standard, sweet, fizzy drink. This is a more serious matter. The trouble only just begins with the bubbles…

As a means of providing a brief introduction, Moscato d’Asti is a low-alcohol sweet white wine made from the Moscato grape (grown in the Asti province in Piedmont of northern Italy). The sweetness does not come from adding sugar. Instead, it is provided by the natural sugars remaining from halting the fermentation. I prefer not to get overly technical, so here is a short tale from the 2008 vintage when I worked in a small town called Castagnole delle Lanze at La Spinetta winery.

It was the beginning of September and the Moscato vineyards were almost ready. La Spinetta has been making Moscato d’Asti since the late 1970’s, when Giorgio Rivetti took control of his father Pin’s grapes and purchased more from other vineyards to create what was to become one of Italy’s most celebrated Moscato d’Asti wines.

The first week patiently waiting passed by with ease with the team’s attendance at a party in Tuscany to celebrate the opening of their winery in the typically Italian named town of Casanova. Upon completion, we herded the team back to Piedmont where we began the harvest, or la vendemmia as the Italians call it.

Throughout the day, grapes arrived in little red crates piled on a tractor’s trailer. The first session of crushing the grapes was filled with excitement for these were the first grapes to commence the 2008 vintage. Hoorah! I stood on the other side of the crusher, inhaling the sweet smell of the Moscato grape as they passed through the machine. “Ah che buon profumo! (What a beautiful perfume).

Wandering over, I pulled several berries off the bunch to taste and was surprised to find that the flavour was an exact replica of the smell that was wafting around the crushing area. So fresh and so inherently grapey, THIS was Moscato d’Asti!

I remember that just before I left for Italy, I was querying the amount of clothes I needed to take for both work and play. My boss pulled me aside, grabbed me firmly by the shoulders and said, “Krystina, you are not going to a fashion parade, you are there to work. Get involved! But whatever you do, don’t let the men walk over you! YOU need to work like the men!’ Wise advice.

The vineyard workers saw me watching them on the back of the truck lifting the crates continuously into the crusher. One of them beckoned me over to see if I’d like to try lift one. “Certo, mi piacerebbe farlo! (Of course, I would like to do it!) Up onto the trailer I jumped with fellow cellarhand Gianni by my side and together we heaved the basket into the crusher.

The men stood back, “Beh, che forza! Vai Krystina vai!” (Well, what strength! Go Krystina go!)

I cannot recall how many 20kg baskets I lifted immediately one after the other, but I can assure you it was enough to put me on the good side of the men in terms of earning un po’ di rispetto (a little respect).

Back to the winery, post-crushing and pressing, the juice is chilled and left to settle before being filtered twice then being transferred to an autoclave (a pressure tank where the fermentation will occur).

Once the fermentation has begun, it is the job of Giorgio’s son, Andrea, to monitor the autoclave. The Moscato juice ferments in the tank in its sealed environment until the pressure builds to 2 bars, when it then has a valve released. This valve hisses out excess carbon dioxide that is being produced during the fermentation. As tourists walk through the winery they are fascinated by the sweet grapey scent of Moscato and the suspicious hiss coming from a row of tanks. The small valve is controlling the amount of gas retained in the final wine.

One incident almost turned disastrous. A tourist must have thought it would be entertaining to close one of the valves as they wandered through. Fortunately, Andrea was performing his late-night check before heading to bed and noticed one tank had crept up to a dangerous pressure level. For the women of the household and myself at the time, who live in the apartments above the winery, this was cause for a lot of classic gesticulation, yelling and arm waving at those tourists who could have created a lot of damage.

Once the perilous bubbling stage is in its prime and the Moscato has reached 5.5% alcohol, the fermentation is halted quickly by chilling the wine to -2°C. It will then sit in tank for a week with a consistent temperature and pressure of 2 bars, until the time comes around to refine it. Standard clarification techniques proceed under pressure, and then only a week later, the wine is bottled. The high degree of quality control and maintaining the pressure ensures that we see the characteristic fine bead of natural bubbles and taste the delicate sweetness from the unfermented grape sugars. 

Growing up with an Italian background, our family parties were privy to copious amounts of Moscato d’Asti. It may be one of the quickest wines to make and put on the market, but working the harvest highlighted the amount of expertise involved in making a noteworthy Moscato d’Asti. I am proud that I was able to experience its production and at the same time, delighted to have worked just as hard as those unsuspecting vineyard men. I think that next time they will not judge an Australian girl so quickly.

Tags: Asti, Fermentation, La Spinetta, Moscato, Moscato d'Asti, Piemonte, Sparkling