Making Moscato and Nebbiolo using frozen Vino Superiore must

 

November 30, 2015

In August 2014, I made some 2011 and 2013 Sangiovese wines using frozen must from Vino Superiore. Although I have not yet bottled the wine, taste tests confirm that these Chianti-style wines are awesome now but which will be outstanding with some aging. I prefer to let my full-bodied reds age and develop into something grander than what 12- or even 18-month-old wines offer. Time and patience always reward a winemaker with stupendous wines.

So this year I decided to try something else from Vino Superiore, something as good, but something different from the usual Merlot, Cab and Chardonnay. I love Moscato and Nebbiolo wines, and so, those piqued my curiosity. Vino Superiore, through Keystone Homebrew Supply in Pennsylvania, arranged to deliver two 5-gallon pails of Moscato and one of Nebbiolo, right to my doorstep, er, driveway since I also purchased 15 pails of 2011 Sangiovese to stock up my cellar, you know, for the future. Once the paperwork for customs and all was completed, the shipment took less than 2 days. The pails arrived frozen, rock-solid. Each contains juice and crushed grapes, even for the Moscato, and yields approximately 4 gallons (12 liters) of finished premium-quality wine.

Both varieties are from the 2013 vintage. The grapes are harvest and processed, and immediately frozen (not pasteurized) for storage. The Moscato is from Falsetto, a 16-year-old vineyard that rises some 400 m (1312 ft) above sea level, and was harvested and processed September 17, 2013. The Nebbiolo is from Cappelo del prete, a 14-year-old vineyard that sits 500 m (1640 ft) above sea level, and was harvested and processed October 15, 2013.

Wines of Piemonte

Moscato and Nebbiolo are two of the most important varieties in Piedmont in northwestern Italy.

I love everything about Piedmonte, just like Tuscany—the wines, the local cuisine and the landscape, hence why I prefer to refer to the region as Piemonte, as it is called in Italian. The cities and communes of Asti, the capital of the Province of Asti, and Barolo in the Province of Cuneo, are synonymous with Moscato and Nebbiolo wines, respectively.

Moscato Bianco

Nebbiolo

Moscato is an intensely aromatic and fruity white variety that can be crafted into many different styles—the two most popular in Piemonte are Moscato d’Asti and Asti (formerly known as Asti Spumante).

Moscato d’Asti is a refreshing, lightly sparkling style with 5–6% alcohol with some residual sweetness to balance the usually high acidity in grapes from this region. Asti is a semi-sweet, fully sparkling wine with more alcohol, usually around 9%. To compare the extent of “fizziness” in these wines, Moscato d’Asti has a minimum of 1 bar of pressure (approx. 15 psi) whereas Asti has a minimum of 4 bars (approx. 60 psi).

Nebbiolo is usually referred to as Barolo, the commune where it is king, although it extends beyond.  The wines are full-bodied with robust tannins, exhibit a characteristic aroma of tar, and display a familiar rusty-tinge color typical of old Barolos as they age, and they can age gracefully for several decades. The best Nebbiolos in top vintages are so bold that they need a few years to settle down and become approachable. More modern styles are crafted so that they can be enjoyed when 4-5 years old to fully appreciate their fruity character.

Given the cooler climate in Piemonte, these varieties typically have high acidity, and Nebbiolo can also be a challenge extracting color due to lower phenolic ripeness. And so, the winemaking must take these factors into account to balance acidity and adopt strategies to extract as much color as possible from Nebbiolo.

My plans for these varieties

With the Moscato, I will make an Asti (by carbonation) and a completely still, off-dry Moscato.

I will start fermenting the juice from both pails together and then siphon off half to make the off-dry style when it has reached 5–6% alcohol, at which point I will cold-crash it to stop fermentation. This will also leave some residual sugar and sweetness. I will balance acidity and sweetness at the end with some Moscato juice that I will reserve in the freezer. Once stabilized and clarified, and acidity and sweetness balanced, I will bottle the wine with no fizz or bubbles.

The remainder of the batch will be used to make an Asti-style bubbly. True Asti is fermented in stainless steel tanks using a variation of the Charmat Method to keep the natural CO2 gas and bubbles trapped in the wine, which is then bottled under pressure so as not to lose precious gas. This is quite complicated in a home winemaking setup, hence why I will be doing it using the carbonation method. I have done this many times in the past with excellent results. I will cold-crash this batch when it has reached approximately 9% alcohol. This too will leave some residual sugar and sweetness, and which will be balanced with reserved juice. Once stabilized and clarified, I will carbonate the wine with CO2 gas and bottle using a counter-pressure device.

I will make the Nebbiolo into a full-bodied, oak-aged style it so deserves.

Making the wines – Day 0: Getting every ready

Since I received the pails frozen rock-solid, I left them to thaw completely for about 72 hours. When I opened the pails, the aromas, especially the Moscato, quickly filled my home winery.

 

 

 

For the Moscato, I poured the juice from both pails into a single small demijohn, and pressed the grape solids very lightly with my small fruit press. I worked as quickly as possible to minimize oxygen uptake as Moscato can be sensitive to air if mishandled. Once finished pressing, I purged the headspace with CO2 gas to protect the juice from oxidation. I placed the demijohn outdoors in our chilly Montreal weather to allow the juice to settle for about 24 hours. This is to allow removal of pulp and other solids prior to fermentation. We don’t want unnecessary matter impeding fermentation. Many winemakers further clarify the juice with bentonite but I prefer not to. I was sure to cover the demijohn with a dark-green garbage bag to protect the juice from sunlight, which can hasten oxidation.

For the Nebbiolo, I poured the contents of the pail into a 6-gallon (23-liter) pail to allow for expansion and rising cap during fermentation. The color is beautiful but I know it will be a challenge extracting more for a deeper color. There are several strategies to use to help extract and stabilize color. Delestage is one technique used in making Nebbiolo and very popular in making Gamay and Pinot Noir in Burgundy. Performing delestage in a small batch like this is not effective, and so, I will be doing punchdowns instead. However, to extract and stabilize color, in addition to pectic and color-extracting enzymes, I added TanÉthyl Effe, a mix of ellagic and proanthocyanidinic tannins extracted from grape pips, which build ethanal (acetaldehyde) bridges among polyphenols to stabilize color. I will also add some oak chips, which in conjunction with aeration techniques, will also help stabilize color.

Making the wines – Day 1: Assessing winemaking parameters and inoculating

I took the Moscato back into warmer quarters where I racked the juice to another demijohn being careful not to disturb the sediment. I racked very gently to minimize oxygen uptake as the juice was quite cold. You’ll recall from high-school chemistry that gas (i.e. oxygen in this case) is more soluble at lower temperatures.

I also transferred approximately a 6%-volume of juice to a freezer bag and placed in a deep freezer. I will be using this reserved juice to back-sweeten the wine prior to bottling.

I took 100-mL samples of both the Moscato and Nebbiolo juices and headed to the lab to run some measurements. The key parameters to measure are: Brix/SG, potential alcohol (PA), total acidity (TA), pH and free sulfur dioxide (FSO2). I ran the samples through a centrifuge to remove as much suspended matter as possible.

Given the flash-freezing process, it is to be expected that sugar and acidity levels in the Nebbiolo will be low at this point. Once the grape solids have had a chance to macerate and fermentation to start, those levels should rise somewhat, and so, I’ll be sure to take new measurements then.

Following are the measurements:

Brix/SG/PA measurements were taken using a hydrometer. TA, pH and FSO2 were measured using a Hanna 902C potentiometric titrator and appropriate probes.

The first thing I noticed is that the FSO2 in the Moscato dropped quite a bit. I added potassium metabisulfite (KMS) to add 35 mg/L of FSO2.

The Brix on the Nebbiolo is a bit low for me, but before I chaptalize, if need be, I will re-measure again once fermentation begins as I suspect more sugar will transfer from the grapes into the juice. Acidity is good, but again, it might rise a little just before fermentation. Since I don’t expect a drastic rise in TA, I will make any necessary adjustments after alcoholic and malolactic fermentations and cold stabilization. To help stabilize color and to increase mouthfeel, I added 4 g/L of French oak chips.

I stirred everything up nicely to homogenize the temperature, raised the temperature a little in anticipation of inoculating in about 12 hours when the temperature is adequate.

For the Moscato I chose a Fermol Arome Plus yeast from AEB. For the Nebbiolo, I chose a Lalvin BM4X4 yeast from Lallemand although I would have preferred a BRL97, but I did not have any available. The BM4X4 is still highly recommended for this variety. I rehydrated the yeast at a rate of 5 g for every pail and a half along with 30 g/hL of Go-Ferm yeast nutrients.

Once fully rehydrated (approx. 15 minutes), I pitched the yeast cultures into the juice, gave it all a good stir, and covered/closed the containers.

Now we simply wait for nature to take its course and for fermentation to start.

Stay tuned! This should be fun.

Daniel

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