Montinore Estate is one of the largest producers of biodynamic wines in the world.

FOREST GROVE, Ore. — Using cow pies and cow horns to make better wine might sound a little gross, but it's exactly what one Forest Grove vineyard is doing.

In fact, it is an annual ritual at Montinore Estate in Forest Grove. Every spring, owner Rudy Marchesi digs up cow horns stuffed full of cow manure.

But before you think it's gross, you have to understand this is actually a very important part of the vineyard's winemaking process.

You see Montinore Estate is one of the largest producers of biodynamic wines in the world.

"What we're doing is providing an environment where these grape vines have the absolutely largest array of nutrients and minerals they can get," Marchesi said.

Instead of using pesticides, herbicides or synthetic fertilizers, the vineyard uses only natural ways to grow its grapes.

One of those ways is by using the cow horn manure. Here's how it works.

In the fall, between 100 and 120 cow horns are stuffed with cow manure and buried. Six to eight months later they're dug up. The manure inside, by then, is more like compost than poop.

"This stuff is very, very rich in nutrients and biology and we'll make a tea out of this and spread it on the ground... around the roots of the plants," Marchesi explained.

Marchesi said stuffing cow horns with cow poop is not the most pleasant of experiences.

"It's not my favorite thing to stick cow manure in horns," he said.

But it's dirty work that does pay off, not just for the environment, but for anyone who enjoys a nice glass of Willamette Valley wine.