Two decades ago, Simi Winery in Healdsburg made a splendid chenin blanc. It was as tasty and as easy to like as a spring morning. And it was easy to make, easy to sell and it made a profit.

Then one year, the winery decided not to make it any more. What had happened was that the parent company decided to cut a number of SKUs.

SKU stands for stock-keeping unit, and is used for almost all other goods. In wine industry parlance, an SKU is a unique wine in a winery’s portfolio. If a winery ends up bottling 15 different wines in a year, it has 15 SKUs.

In general, large wine companies don’t like having a lot of SKUs. And you can imagine what happens when a giant winery gobbles up a smaller one: Some wines end up on the cutting room floor.

That’s what has happened to many wines as a result of mergers in which the new parent company wants to simplify what it sells.

Wine industry consolidation has been going on for two decades, reducing the number of players, but keeping old brands as staples for marketing purposes. What remains in most winery portfolios are the wines we have come to know well because they carry familiar names.

So we have a lot of chardonnay, cabernet sauvignon, merlot, sauvignon blanc, pinot gris. As a result, what we are losing are fascinating wines such as semillon, chenin blanc, charbono and barbera.

Recently, however, I have seen an interesting trend: Small wineries are turning to some of these wines for their wine clubs.

Consumers join a winery’s wine club because it offers more than just the standard wines. This counter-trend allows wineries to make cabernet franc, malbec, dry rosé, dry riesling, petite sirah, and many other wines that are sold only at the tasting room and by mail order to wine club members.

As a result of wine club needs, some wines that once were popular and then were abandoned are coming back. So while larger wine companies simplify their portfolios by abandoning SKUs, small wineries are adding eclectic wines in small amounts that actually expand the number of SKUs being made.

Of course, the only way some of the “unusual” varietals can be made is if someone is still growing the grapes. At one time, chenin blanc was made by a wide range of wineries including Kenwood, Charles Krug, Simi, Stags’ Leap, Girard, Raymond and Burgess. Little of that grape remains in top North Coast regions, so only a handful of wineries are making it.

The good news is that smaller, adventuresome producers are making small amounts of French colombard, carignan, chenin blanc, pinot blanc, lagrein, trousseau gris and other grapes. The trick is to find them, which means visiting tasting rooms.

And the first question I would ask is, “What do you make that is for sale only here?”

Wine of the Week: 2008 Dry Creek Vineyards Dry Chenin Blanc, Clarksburg ($12) — This delightful wine has been made by Dry Creek for decades. The wine, bursting with melon-y fruit, has a crisp aftertaste since the sugar is just a half percent, but the wine also is succulent and easy to drink with seafood, Japanese food, or other Asian foods. Widely available.

Dan Berger lives in Sonoma County, where he publishes “Vintage Experiences,” a weekly wine newsletter. Write to him at danberger@rocketmail.com.