More and more of my customers are asking about organic wines, and I’m delighted to have a dialogue about them.

Some are suspicious. Is it a trendy marketing gimmick or a demonstrably better way to make wine? In fact, there are many ways grape growers go about protecting vines and soils: Biodynamic, organic or other eco-certifications are not the only ways to do it. Even without certification, a wine can still be sustainably produced.

So what do I mean when I talk about sustainability? According to Jamie Goode's book Wine Science, "In the 'natural' situation of an ecosystem, checks and balances develop. ... Any system that is hopelessly imbalanced is unsustainable, so it is selected against. This means that the ecological systems that have survived are by definition, sustainable, unless they experience some externally applied change, such as someone planting a large vineyard in the middle of them."

The trick for a grape grower is to protect vines from disease or risk losing a significant part of the crop. The easiest, cheapest route is to use pesticides and herbicides. But nature always catches up. Given a long enough timeline, natural selection will eventually come up with a disease-resistant strain of insect or weed or bacteria or whatever kind of threat a pesticide was intended to eliminate. A "sustainable" grower will encourage grapevines to be part of a complete ecosystem, rather than a monoculture.

I like to use sustainability as a starting point to establish why it's important to be conscious of the way wine is made. Organic, biodynamic and natural winemaking are related to sustainability, but have more strict interpretations about how to implement it.

Making wine is more than growing grapes; those grapes need to be fermented into alcohol in order to produce the final product. So there's still great debate about applying the principles of sustainability not only in the vineyard but the cellar as well.

If a wine is doctored with a concentrate like Mega Purple and pumped full of additives, the benefits of growing grapes in healthy soil for the consumer are effectively negated. Hence the great debate about "made with organic grapes" versus "organic wine." What happens in the cellar that could interfere with the organic integrity of the grapes? (It boils down to the addition of sulfur, which is strictly limited in USDA- certified organic wine; EU-certified organic wines have much more flexibility.)

There are over 80 different additives that can be used during the fermentation process—which is jarring to think about, when all you really want in your wine is grapes and yeast. But there are products for clarifying, stabilizing, preserving, aromatizing, de-acidifying, chaptalizing and coloring. A responsible winemaker eschews the products that are bad for the environment. If a wine is certified organic or biodynamic, the same rules that applied to the growing of grapes must also apply to each additive. Meaning, if you're going to buy commercial yeast, the yeast must also be certified organic. It's complicated, but a great shortcut is to find winemakers who make wine in a conscientious style, rather than rigidly regarding one style of certification as the only way to make wine.

So, without being too pedantic about it, here are a few of my favorite producers of environmentally friendly wine.

When it comes to organic wines, are they all expensive? They don't need to be. The 2015 Ontañon Ecológica retails for $15 and is EU-certified organic. It's Tempranillo sourced from vineyards on the high slopes of the Sierra de Yerga mountains in Rioja, where rates of pests and diseases are especially low. It's a fabulous wine, and the range of Ontañon wines are well worth seeking out.

Since it's rose season, it's also worth seeking out the 2016 Vin Gris rose by Robert Sinskey. This dry, pinot noir-based rose hails from cool climate Carneros (Napa Valley). "Grow it well and try not to mess it up" is the resident winemaking philosophy, and it shows. This wine is a little more expensive than the average rose at $32, but it is a worthy warm-weather treat.

Farming organically in a region like Champagne is a seemingly impossible task. (In fact, the most criticized aspect of organic farming is that it tries to accommodate too many diverse regions and climates under a blanket set of tenets that don't always translate very well to different circumstances.) The climate is humid when warm and brings the constant threat of mildew and odium. But Pascal Doquet makes an incredible Champagne for $49, Diapason, sourced from his own Grand Cru vineyards in the village of Le Mesnil-sur-Oger. He's been EU-certified organic since 2010, and farming sustainably since 2003. This particular wine is lovely, elegant and complex, a great example of a finely crafted wine from a thoughtful grower and producer.