Quality Over Quantity: Why We Intentionally Leave Juice Behind
The chemistry of the crush
At Veritas Estate, when harvest season arrives, the air in South Haven turns crisp, and the pressure—both literal and figurative—starts to mount.
As a winemaker, I’m often asked, "What’s the hardest decision you make?" Most people expect me to say "when to pick." And while that final sugar and total acidity check is vital, the real magic (and the real science) happens the moment the grapes hit the press. It’s a delicate dance between extraction and restraint, and it all comes down to two silent players in the glass: Potassium and pH.
The Anatomy of a Grape: The Grape Skin is the Key
To understand a great glass of wine, you have to understand the grape’s architecture. The juice in the center of the berry is high in sugar and bright acidity (tartaric and malic acids). But the skins? That’s where many complex chemicals and flavors are stored. It is also a major source of potassium (K+). When winemakers and wine experts talk about "skin contact," we’re talking about how long the juice sits with the grape skins. In red winemaking, we want skin contact for color and tannin. In whites or rosés, we have to be incredibly careful.
Here is the chemistry at play: When we apply pressure during pressing, we aren't just getting juice; we are breaking down the cellular structure of the skins. This releases potassium (K+) into the must. The potassium ions then react with the natural acids in the juice and titrate the acid (specifically the hydrogen ions or H+). The result? The more we press, the more potassium we extract. This "uses up" the acidity, causing the pH to rise. A higher pH means a wine that feels "flabby," loses its bright fruit character, and is much less stable over time.
The Sacrifice of Pressing Lightly
This is where the business of winemaking meets the art of winemaking. If I were looking purely at the bottom line, I’d crank the press to the max. I could squeeze every last drop out of every ton of grapes, maximizing our yield and filling more bottles. But "hard-pressed" juice is a different beast—it’s loaded with potassium, it’s more bitter, and it lacks the precision I strive for at Veritas Estate. Instead, I choose press lightly, gently increasing pressure while monitoring the pH of the must being released and stopping long before I start extracting those harsh potassium levels from the skins. The trade off is that I get significantly less wine per ton of grapes. We are literally leaving juice behind in the skins. But what we do bottle is vibrant, balanced, and has that signature crisp finish that Veritas Estate, and many other Michigan wines, is known for.
Why You Can Taste the Difference
When you sip our Pinot Gris or our Beach Day Rosé, you’re tasting a wine with a lower, more energetic pH. Because we didn't "over-press," the natural acidity is allowed to shine, unburdened by excess potassium. It’s the difference between a blurry photograph and one in high-definition.
The next time you visit us at the Inn, ask me about the skin contact or the decisions I made during the crush of the vintage you're drinking. I might get a little nerdy about potassium levels, but one sip will tell you exactly why we choose quality over quantity every single time.
Visit Veritas Estate in South Haven and taste the science, skill, and intention in every glass.
In Vino Veritas!
-Dr. Sherry Seston
Glossary:
Must: The "raw material" of winemaking. It is the unfermented mixture of freshly crushed grape juice, skins, seeds, and sometimes stems.
pH: A logarithmic scale measuring the concentration of hydrogen ions. In wine, a lower pH (higher acidity) acts as a natural preservative and keeps the flavors bright. Acidity is also key to preserving wines naturally without excess sulfur dioxide.
Potassium (K+): A mineral found in the skins and pulp of grapes. While essential for vine health, too much of it in the juice can neutralize the wine's natural acids, leading to a "flat" taste.
Press Fractions: The different "batches" of juice collected at various pressure levels. Winemakers often taste and test these in real-time to decide when to stop the press before quality drops.
Tartaric Acid: The primary acid in grapes. It’s one of the acids responsible for the tartness we love in a crisp white wine. Other acids naturally found in grapes include malic acid and citrus acid.