Why We Don’t Filter: The Case for Unfiltered Wine

At Madrone Cellars, we often get asked, “Why unfiltered?” It’s a fair question — after all, most wines on the shelf are crystal clear (*the technical term is brilliantly clear - Wine Spectator definition - Describes the appearance of very clear wines with absolutely no visible suspended or particulate matter. Not always a plus, as it can indicate a highly filtered wine from which many of the components that contribute flavor have been stripped), polished by modern processes that remove sediment and stabilize added sugars and malic acid. But we believe that nature does the best work when left to express itself, and filtering gets in the way.

So here’s our honest answer:
We don’t filter because it makes better wine.

What Does “Unfiltered” Mean?

In the most literal sense, unfiltered means we don’t use filtration or fining agents to clarify our wines or ciders. But the reality runs deeper than that.

When we say a wine is unfiltered, we mean that we allow it to finish and evolve without removing the natural components that develop during fermentation — like yeast, polyphenols, and proteins. These are often seen as “haze” or “sediment,” but to us, they’re far more than that. They are part of the soul of the wine.

These naturally occurring elements not only enhance flavor and mouthfeel, but they also play a powerful role in protecting the wine from spoilage over time.

At Madrone, we allow the wine to settle naturally, and we only rack (gently remove the liquid from sediment) once just before bottling. The wine rests sur lie — a traditional French method that means “on the lees.” Lees are a complex and beautiful mix of yeast, proteins, bacteria, and polysaccharides that settle at the bottom of the tank or barrel. While many commercial winemakers filter them out, we leave them in.

Why?

Because the lees protect the wine and add flavor and mouthfeel.

Nature’s Built-In Defense System

Here’s where it gets even more fascinating. As wine ferments, it develops mannoproteins and antioxidants — not additives from a lab, but compounds born directly from the yeast and grape skins. These natural molecules protect the wine from oxidation, which is one of the biggest threats to aroma and flavor stability.

Lees  (the settled yeast and proteins at the bottom of the barrel) aren’t just sediment — they’re packed with compounds like flavonoids, polyphenols, mannoproteins, and polysaccharides. These act as natural antioxidants, scavenging oxygen and preventing oxidation, which is one of wine’s greatest threats to flavor and aroma.

But these are precisely the things that act as nature’s own stabilizers. In fact, modern biotech is actively trying to isolate these natural antioxidants from waste wine lees for pharmaceuticals — that’s how powerful they are! *

When we leave them in, they help preserve the wine’s vibrancy, structure, and character — not just for a few months, but often for years.

What Happens When You Filter Wine?

Filtration doesn’t just remove haze — it also strips away many of the expressive elements of the wine: flavor compounds, aromatics, texture, and stability. It’s a shortcut that often requires synthetic intervention later to make up for what was lost.

By not filtering or using fining agents, we preserve:

• The authentic flavor profile of the grapes

• The protective qualities of the lees

• A sense of terroir (pronounced: tehr-wah) — the true character of the grapes, the yeast, the climate, the soil, the vineyard, and the season.

So... Why Unfiltered?

Because we believe wine should speak for itself.

We’re not interested in stripping it down, polishing it up, or controlling the outcome with chemistry. We’re interested in honesty. And in our experience, unfiltered wine is:

• More expressive

• More alive

• And more delicious

We’re not trying to make a product that conforms to modern industry standards.
We’re making wine and cider traditionally, the way it’s been made for centuries — with all the depth, complexity, and nuance that nature built into it.

This is the start of a deeper conversation. Over the coming weeks, we’ll share three more pieces that explore:

• 🍷What Really Happens When Filtering and Fining Wine
  The chemistry of loss and compromise in the name of clarity. We will share a breakdown of the science behind filtering and fining, and what gets lost. 

• 🍷Lees: Waste or Wonder?
  Why we believe the bottom of the barrel is one of the most valuable parts of the winemaking process. Natural source of protection for the wine and an important antioxidant that has captured the medical world’s attention.

• 🍷Antioxidants in Wine: Not Just Buzzwords
  Exploring the powerful natural compounds that protect wine and flavor — no synthetic chemistry required. The case against sulfite additions. 

  We can’t wait to share more about why we believe in unfiltered wine and cider — and how it speaks for itself in every glass. Come in and we will happily pour a glass for you!