(SFExaminer) - Natural winemaking is on one hand a vague term, and on the other, very simple.

After an interview several years ago, I wrote about Kevin McKenna, one of the partners of Louis Dressner, an early importer of “natural wine.” Since then, the term and its philosophy have become much more widespread, not only in France where it first took hold, but also in California.

The basic tenets of natural wine would be:

Employing organic or biodynamic viticulture without the use of any chemicals in the vineyard. Many vintners would also say that certification is a must, as it guarantees these methods are being followed.

Hand-harvesting.

Using natural yeast during fermentation.

Minimal or no sulfur.

No filtration.

The idea behind natural wines is that the wine should be expressive of its terroir. A problem here is that “natural” winemaking methods can result in volatile acidity and bacterial problems. This is true of conventional winemaking as well, but the low use of sulfur makes natural wines more prone to acidity and bacterial issues.

As natural wines are seeping into the consciousness of Bay Area wine buyers, there is bound to be confusion. If you are curious, there are a couple of handfuls of producers from California dedicated to natural winemaking. Here are the most consistent and some of the wines to look for.

Broc Cellars: Located in Berkeley, Chris Brockway’s winery has become a hamlet for many as his wines are seldom less than excellent. The winery is famous for its carbonic carignan, and I love its Cassia grenache and cabernet franc with verve.