It’s no secret that those in the wine industry have strong opinions on all things wine, from regions and producers to winemaking practices and philosophies. Thus, it’s unsurprising that there are certain trigger words that are sure to set off lengthy and heated debates when spoken amongst a group of wine professionals. In recent years, “unfiltered” has joined the ranks of wine trigger words, pitting those who think unfiltered wines are the truest expression of a wine against others who have knee-jerk visions of cloudy, faulty cuvées. With more winemakers making unfiltered wines and marketing them as such, what’s the deal? Are unfiltered wines better?

Fining and filtration have long been considered essential parts of the winemaking process. Both practices are essentially used to do the same two things: first, to clarify the wine, giving it a crystal-clear appearance, and second, to stabilize it, preventing the wine from spoiling or beginning to referment. Fining uses an agent such as bentonite, gelatin, or egg whites (or in the old days, ox blood) to attract miniscule solids and bind them together, allowing the solids to fall to the bottom where they can easily be removed. Filtration is exactly what it sounds like; the wine is pushed through membranes with microscopic openings in order to remove solids such as yeast and bacteria that can remain suspended in the juice. This process, however, is considered to be more aggressive than fining.

So if fining and filtration promote the stability of a wine, why would any winemaker choose not to do it? Over the past 25 years or so, not coincidentally in conjunction with the rise of natural winemaking, some producers have begun to assert that filtration in particular has a negative effect on the character of the wine. According to many, filtration strips a wine not only of solids but of its character as well, resulting in a less flavorful, more generic-tasting wine. This has led to the rise of unfiltered, unfined wines, and the words are often used as a stamp of pride or mark of quality among those who proclaim them to be more authentic, a notion that takes hold among many terroir-seeking consumers.

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Some are staunch advocates of one side or another. “Filtration is a heavily political subject among wine folk,” says Hugh Johnson and Jancis Robinson’s The World Atlas of Wine. Friuli-Venezia Giulia’s Josko Gravner has a history of pioneering unusual winemaking philosophies in his region, often to the bewilderment of his neighbors. One of these philosophies, which came about in the 1990s as many of Gravner’s other signature techniques were evolving as well, was the idea that wines should not be clarified through fining or filtration. According to Gravner’s daughter Mateja, after a stay in the hospital, Gravner attempted to drink his own wines (which were filtered at the time) but became unusually ill, as if his body couldn’t process them.

But upon drinking unfiltered wine, Gravner found that his body had no adverse reaction. This convinced Gravner that that “unnatural” process of filtration was actually removing components of the wine essential for the body. “Wine must contain three things: bacteria, yeast, and enzymes. Clarification eliminates these three things,” Gravner was quoted as saying at a 2012 conference in Rome. Gravner stopped filtering his wines in the late 90s, his switch from barrel vinification to amphorae helping to make it possible, and today, Gravner’s wines are noticeably hazy but layered, vibrant, and incredibly ageable. They are complex, textured wines that warrant contemplation but are still inherently pleasing at the same time.

So what’s the key to making great unfiltered wine? Contrary to what it may sound like, the natural approach to winemaking isn’t quite a “set it and forget it” philosophy. While the process may be hands-off, it’s very much eyes-on; careful observation and patience is required to make quality unfiltered wine. The biggest concern here is exactly what opponents of unfiltered wine associate with the style: faults precipitated by solids left in the wine, justified under the catch-all umbrella of natural wine.

But unfiltered wine does not equal faulty wine particularly because vintners now have a better understanding of winemaking techniques and processes. In fact, it doesn’t even necessarily have to equal cloudy wine. If a wine is aged in oak for an extended period of time, for instance, the natural settling of the wine will allow solids to fall to the bottom of the tank so the wine can be racked, or separated from the solids. Gravner’s wines, for instance, are aged for more than 40 months in amphorae and wooden cask, which ensures that the juice will settle and be stable enough not to need fining or filtration. Some winemakers, like Gravner, will also add a small amount of sulfur to stabilize the wine as well.

So is unfiltered wine better? Not necessarily, which is why the debate wages on. The quality depends more on the winemaker, and the decision to make wines in this style is more of an indicator of the winemaker’s philosophy than the finished product. There are plenty of winemakers who make supreme filtered wines, and then there is Yellow Tail. There are poised, elegant, age-worthy unfiltered wines like those of Gravner, or the legendary Domaine de la Romanée-Conti, for instance, and then there are faulty or uninteresting unfiltered wines that justify the finished product in one way or another. It would be unwise to discount either winemaking decision, but it’s important to know unfiltered wines have the potential to pack in a whole lot of character – all by throwing out the filter.