Ah! Those bad sulfites; they’re such an easy target. What else can people blame for headaches after drinking red wine? After all, there is even a regulation that requires the mandatory mention contains sulfites on all wine sold in the U.S. So there must be some health concerns with sulfites. But why is that not indicated on other sulfite-containing food and beverages? Why is wine singled out? All are valid, interesting questions.

Recent research has shed some light on this controversy as only a very small segment of the population, approximately one percent, is actually allergic, exhibiting asthmatic reactions, not headaches. In fact, very few people, if any, actually complain of headaches after drinking white wines, which typically contain higher levels of sulfite as these are more prone to spoilage effects and therefore need added protection.

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I get asked this question quite frequently, as of lately, particularly in light of recent studies linking bisphenol-A (BPA)—the plastic used to line beverage containers and tin food cans—to cancer. The latest research from the Université de Sherbrooke in Québec, Canada and published in Toxicology and Applied Pharmacology reports that BPA can adversely affect development of the fetus in pregnant women.

 

Until fairly recently, glass carboys were really the only practical containers for fermenting and storing wine available to home winemakers. However, glass carboys are heavy, slippery when wet, and fragile—much wine has been spilled and many people have been injured as the result of accidental breakage.

As I set about to run some trials in disgorging and adding dosage to riddled bubbly—two critical steps in the méthode champenoise (aka traditional method) production of bottled-fermented sparkling wine—I was reminded of an interesting question asked by an attendee at my seminar at the last WineMaker Magazine Conference in Napa Valley: “Why not simply place bottles upside down in carton boxes instead of having to riddle each bottle every day for 21 days?”

Tough question to answer without looking at the physics of what is actually happening during riddling—the process of channeling bottle-fermentation lees down to the neck portion of the upside-down bottle to allow the lees to be expelled by disgorgement and produce a crystal-clear bubbly. A poorly riddled bottle can spell disaster, and turning bottles over to let the lees flocculate without proper riddling simply won’t work.

If bottles are turned over in a case, yes, most of the lees volume will find its way to the neck; but “most” is not good enough. The problem is that some lees particles will cling to the glass—just hold up the bottle against a strong light source and you will see what I mean. These fine lees particles now become nucleation sites for the dissolved carbon dioxide gas. Once the bottle is disgorged and the lees are removed, microbubbles will rapidly form and nucleate at these sites, and then quickly rush up to the surface of the wine in the bottle, and cause the wine to gush out uncontrollably. This is further exacerbated when adding the dosage.

Let’s look at this phenomenon a little closer.

 

In June, I wrote about my frustration with natural corks and the seemingly increasing occurrence of corked wine resulting from TCA (2,4,6-trichloroanisole) taint. It has become so frustrating that I have been seriously considering switching to screwcaps for wines produced at Maleta Winery. I have even my closest colleagues wondering if I have lost it, so to speak.

As I was researching for alternative closures, I had come upon a glass closure invented by the German division of Alcoa and commercialized in 2004 under the brand name Vino-Lok. It’s a closure manufactured entirely of glass and includes an O-ring to ensure an airtight seal with the bottle. A short aluminum capsule over the Vino-Lok completes the packaging for a cool, classy finish.

But I had not been able to source a wine bottle with a Vino-Lok closure for evaluation purposes.

Well, I now have, and I must admit, I am very impressed. The closure looks very classy and is very easy to open. The Germans have been using it now for several years with much success, albeit acceptance is hard to come by with traditional natural corks still leading and screwcaps gaining much momentum even with premium wines.

Can this be the closure of the future? Time will tell. But I certainly see the Vino-Lok as the perfect closure for home winemakers. Glass closures are easily inserted, and are reusable and recyclable, and are inert and therefore there is no risk of contamination.

How perfect a closure is that?

As I was helping out my Italian buddy make wine last evening, I was reminded of the days when my dad would warn me against interfering with wine on a full moon.

Ah yes! Leave it to the older-generation Italian home winemakers to add a dash of their “scientific knowledge” to winemaking: Some of it borders on the paranormal. And last time I checked, none were familiar with the work of Rudolf Steiner (Austrian philosopher and esotericist who founded biodynamic agriculture).

As the son of an Italian immigrant, a home winemaker too (of course), the fall season in Montreal was exciting for me—exciting for many reasons, but mainly because it was the start of winemaking season. I always enjoyed trekking to the local Italian market to buy what now seems like it was always Alicante (Alicante Bouschet) for red wine and Moscato (Muscat) or Thompson Seedless for white wine. There was something fun about buying grapes; perhaps it was because I knew that it would soon be transformed by some kind of magic into wine after I would develop blisters from working the hand-operated crusher, and the fact that I did not know the chemistry—and neither did my father—made the whole experience intriguing. And of course we would have friends and family over, and that meant party, food and wine, well, soft-drinks for us younger ones. But I digress.

While attending a wine appreciation class, an inquisitive student asked if wine could be manufactured in the lab. “Yeah, sure,” said the teacher without missing a beat, but offered no further explanation. Quite a disappointing response it was; one which seemingly reduced wine to a simple, matter-of-fact drink. What a great missed opportunity to educate!

The teacher was nonetheless correct—you could theoretically make wine in a lab, but, practically, an almost impossible task.

Wine is a very complex beverage; it consists of thousands of simple and complex organic compounds, many of which have not yet been identified although Ted Rieger states in the May–June 2009 issue of Vineyard and Winery Management that “[r]esearchers believe that most of the chemical compounds in grapes and wines that contribute to aroma and flavor have now been identified.” Organic compounds include alcohol, acids, phenols, sugars, esters, amines and aromatic compounds, which all contribute to the positive aromas and flavors found in wine, as well as other organic compounds such as aldehydes and thiols that impart off-flavors or cause spoilage. These compounds are synthesized in the grapes during the growing and ripening cycle, and can be created during fermentation from selected yeast as well as from winemaking operations such as barrel aging. And there are inorganic compounds derived from soil and nutrients therein.

And these compounds all exist in varying concentrations from the measurable to trace amounts, and in countless combinations and permutations, all a function of the plethora of grape varieties, differences in viticultural practices and factors such as soil and climate, and kinds of yeasts, making the concocting of wine in the lab an impossible task.

An interesting question indeed; but why try and reduce such a mystical beverage to some lab-concocted solution?

Um, I think I’ll go have a glass of wine to explore this further.

Winemaking season is just around the corner for many of us—those who make wine from grapes—and I’m thus reminded of the old adage that “great wine is made in the vineyard.” And that means planning, lots of planning.  

Your plans should include what kind and style of wine you would like to make, where you will source the grapes, and when you can expect the grapes so that your home winery is ready to get-go as soon as the fruit comes in.

These all pose many challenges as your fruit is still hanging on the vines, under Mother Nature’s close watch and control, and you won’t know the quality until harvest. If you source grapes from your own vineyard, then you have a lot more control than if you buy grapes from a grower or via a purveyor where there are middlemen involved. So monitoring “your grapes” and assessing quality before the grapes arrive is pretty much left to chance in many cases. And so you have to work with a reliable, reputable and trustworthy grower, purveyor or other supplier, and be sure of what you buy—that means know your grapes and how much you should expect to pay for specific varieties. If the quality of the fruit is not up to your standards (or contracted terms, if so lucky to be able to do that), don’t be afraid to reject the load. Why make subpar wine with top dollars?

To help you plan your grape winemaking, here are some important questions to ask before buying grapes: Where is the vineyard located? Is it in a warm- or cool-climate region? How reputable is the grower or vineyard? How and when were the grapes packed and shipped? What should I expect to pay for specific grape varieties from this supplier?

Cool-climate grapes will tend to have higher acidity, lower sugar concentration and, quite possibly, different flavor profile and character. Grape chemistry and physiology also depend greatly on how grapes were grown and harvested, information typically not available to buyers. For example, some growers harvest for quantity, not quality, because they get paid “by weight”, and quality suffers as it is inversely proportional to quantity. Quality greatly declines when grapes are harvested at high yields because water content in berries dilutes sugar, acidity, color and flavors, and would result in a lighter, “thinner” wine.

Grapes packed in cases or bushels “in house”, as opposed to in the vineyard, will usually look healthier having gone through a triage to weed out leaves and green or spoiled bunches before being shipped. For cost-saving and expediency reasons, field-packed grapes do not go such triage and will tend to have undesirable elements that need to be sorted out prior to crushing.

Ideally, grapes should be handled minimally and delivered to the crusher as soon as possible after harvest. Grape chemistry, physiology and flavors are always compromised during excessive handling or delayed shipping.

Research the market price in your area for each grape variety to make sure you are getting what you pay for. If the price of Cabernet Sauvignon grapes is expected to be in the US$1 per pound range in your market (premium grapes from premium vineyards typically cost much more), Cabernet Sauvignon grapes selling at almost half the price are almost definitely not genuine.

The next tip is to properly research grape varieties you are considering buying so that, if you want Cabernet Sauvignon, you get Cabernet Sauvignon and not a blend of inferior varieties. For each variety, study the physiology of the grape bunch, berry and leaf, and its expected chemistry and flavor profile. Consult the many books and internet-based resources dedicated to ampelography, the science of description and identification of the Vitis vine species and its cultivated vine varieties.  Once you have found a grower or supplier that can source and deliver your desired grape varieties, choose grapes with great care.

First, perform a thorough visual examination of the grapes. The grapes should look fresh, clean and healthy. There should be no shriveled, spoiled or rotten berries or bunches; reject any batch that does not look healthy. Stems should look green, but not overly green, which could otherwise impart unpleasant, harsh tannins to wine. Whitish residue from vineyard sprays, such as sulfur-based products, should never be excessive, which could otherwise cause hydrogen sulfide problems (rotten-egg smell) in the wine.

Examine a sample of whole grape cluster for shape and size to ensure that they are typical of the variety.    Then, take a sample berry, wipe the residues and examine its color, shape and size, and thickness of the grape skin. If the color does not look right for the variety, then it may not be what has been declared. Ideally, there should be no leaves with grapes when shipped or picked up from a local market; however, if there is at least one leaf, examine its morphology—shape, size, number of lobes, shape and size of serrations, etc.—to get some clues about variety.

Leaf morphology alone cannot provide a definitive answer on variety as it can vary even for leaves from the same vine. This is also very difficult to assess by an untrained eye, so study hard and long.

As a second step, quantitatively assess sugar content in grapes, if possible. The sugar level determines a wine’s potential alcohol level. Ideally, you should also measure acidity and pH, at a minimum, but this is seldom practical. Some growers may provide such data. Growers or purveyors usually don’t like it when winemakers show up with a hydrometer to test sugar content because that means crushing a whole cluster or more of grapes— both messy and a waste. Rather, the best (and most discreet) method to determine sugar content is using a refractometer where only a couple of drops of juice are required, and the reading is instantaneous.

The last and most critical step is the gustatory test, i.e., how do the grapes taste? There is a direct correlation among the grapes’ and wine’s flavor profile, complexity and intensity. Taste a couple of berries while chewing them slowly and (discreetly) spit out the seeds, and let the juice cover the tongue as much as possible. Evaluate flavors, their intensity and complexity along with sweetness and acid balance, and tannin quality. The importance of this assessment cannot be overstated—flavor is as important as sugar and acidity when determining when to pick or buy grapes.

As a last tip, always be prepared for the unexpected. If you buy grapes and you then realize at the crusher or press that the sugar or acidity are off, you will need to make prompt adjustments. That means you should have a good stock of essential additives necessary for making corrections, including sugar (table sugar is fine), tartaric acid for increasing acidity, and acid-reducing additives for reducing acidity. And remember to have a supply of all other additives that you typically use in winemaking including sulfite, yeast, yeast nutrients and enzymes. Draw up a checklist now and order all additives asap; you don’t want to be caught at the crusher with your local supplier out of your favorite yeast.


Daniel Pambianchi

I recently hosted a Supertuscan tasting that was to be memorable given the lineup of wines, which included vintages of Guado al Tasso, Solaia, Sassicaia and Masseto. It surely was memorable, but for all the wrong reasons: The much-anticipated bottle of 2001 Masseto was, argh, corked. Wretched TCA! It almost drove me over the edge, well, almost. Corked Masseto!? 2001!? That hurts. So, being the scientist-minded person that I am, I decided to explore this further and see how I could fix this problem-aside from switching over to screwcaps, which I'm still resisting, being the traditionalist that I am.

TCA, short for 2,4,6-trichloroanisole, is a compound that produces a moldy, musty smell and is the result of a chemical reaction between phenolic compounds, present in both oak wood (Q. suber) and wines, and mold or chlorine, and which can be detected at extremely low concentrations, in the ng/L, or parts per trillion (ppt), range. The smell is what is referred to as "corked," which is unmistakably detectable in affected wines and which mutes aromas.

I had once read that TCA can be "removed" using butterfat or polyethylene (a thermoplastic). I never had the opportunity to try these out, but this Masseto experience gave me a serious incentive to experiment and confirm the remedies. Would they work?

In my last blog, I said I would share expert tips and secrets to help you craft award-winning wines. I shared some of these with the attendees at the second annual WineMaker Conference in Napa, May 15-16. There, I also had the opportunity to taste many, many wines – all in the spirit of improving winekind – that proud home winemakers shared with all at the wine swap & tasting party. I was impressed by many of the wines, while others were quite good but lacked that one element that would make a huge difference; and then there were those that simply need more work, mainly because of some obvious fault.

Tip #1: Experiment, discover, learn and adjust.

This is the great thing about home winemaking – the ability to craft wine unconstrained by appellation bylaws, biases, or traditions – where just about anything goes. And I have had the pleasure to taste many great wines that were uncommon or unusual blends, but the proof was in the, well, wine. So don’t hold back. Try different blends; try unusual combinations, perhaps even blending viniferas with hybrids. Learn from your experiments and then adjust accordingly. And get the opinion of fellow winemakers and friends; they will give you honest feedback.

Tip #2: Protect your wine from oxidation

I still taste too many wines that suffer from slight or even excessive oxidation. Protect wine from air intake during processing and maintain an adequate free SO2 level. Many still shy away from sulfite additions. There is absolutely nothing wrong with adding sulfite. Why risk spoiling your wine?

Tip #3: Strive for balance

Award-winning wines are those that deliver balance – balance in the aromas, flavors and taste. When any one element dominates, it can overwhelm all the other elements and diminish quality of the wine. Oak is often a culprit; it can hide fruity aromas and make the wine taste bitter and overly “woody”. Most important is to make sure that acidity, sweetness, alcohol and mouthfeel are all in harmony. Achieving mouthfeel is so important that we’ll make this a tip of its own.
 

Tip #4: Use gum arabic to improve mouthfeel

Need to improve mouthfeel in that luscious Pinot Noir? Try adding gum arabic, such as Arabinol. It does wonders for mouthfeel, and it’s a perfectly safe and common additive in the food and beverage industry. And for that full-bodied Chardonnay, try lees stirring.

 

I must confess I enjoy winemaking—some will say I'm obsessively addicted to it—not only because it allows me to craft something out of my own hands and then get rewarded by drinking great wine (ok, there is the occasional batch that is not so great) paired with soulful Italian food in company of my friends and family, but also because of the tremendous learning potential. In 2004, I have even decided to launch, perhaps foolishly, a commercial winery in beautiful Niagara-on-the-Lake in Ontario, Canada.

Although wine has been made for 7,000 years, our knowledge of the science of wine and winemaking only took root in the 19th century. And it's only been in the last 30 years or so that academia and the industry have made great strides in understanding wine science, from wine chemistry, biochemistry, microbiology, and biotechnology to wine appreciation as well as its impact on human health.

Whatever the cause, whether it was a cultural awakening with the influx of post-Prohibition immigrants, the famous 1976 Judgment of Paris, or CBS's airing of the "French Paradox" on 60 Minutes, there is rekindled global interest in learning from our winemaking forefathers and advancing wine technology. Just look at the Aussies! They are hungry to learn all that is wine, and that hunger feeds ambition—ambition to drive innovation. Indeed, Australia has become a world leader in winemaking innovation.

And it's in that same spirit that I tackle this wonderful hobby of home winemaking. I have an insatiable appetite to learn—and to share with fellow winemakers. I read relentlessly. I experiment and try different things. I watch and learn from others. And I drink a lot of wine. Let me rephrase that. I drink a lot of different wines for the purpose of learning about the winemaking of all regions, about different grapes, about kits, and the story behind each great bottle of wine.

So