I spent last weekend in San Diego, where I was judging the Critics Challenge, an annual wine and spirits competition run by Robert Whitley and judged by wine critics from around the country. For me, that meant more than 200 wines in a day and a half, bottles that hailed from California, the rest of the country (I tasted several from the state of Georgia, for example) and the rest of the wine world.

Many of them were very good; a few were even spectacular. But I also came away with a couple of perplexing observations.

Observation No. 1: When did cabernet sauvignon become a dessert wine? I tasted 25 cabernets from California, Washington, Australia, Chile and Spain. The descriptor “sweet” appears in my tasting notes for more than one-third of them.

A little residual sugar can soften the finish of a wine or make it taste fruitier. But cabernet sauvignon should not taste overtly sweet. In the case of this group of wines, the sweet ones were all under $20. But as cabernet has gotten riper, I’ve also seen a trend to more sweetness in the higher price tiers.

I’ve gotten used to tasting chardonnays that are noticeably sweet – I don’t like the trend, but it doesn’t surprise me anymore. The high percentage of sweet cabernet, however, was a surprise. (And I heard other cabernet judges remark on the same thing.)

Another regrettable trend: About half the sauvignon blancs I tasted were also noticeably sweet.

Observation No. 2: Domestic riesling is most successful when it’s dry, just off-dry or very sweet. Medium sweet, not so much. Admittedly, this observation is based on a limited sample of five wines (although I’ve tasted plenty of these types of wines in other venues). Most of the wines, which ranged from 2 percent to 4 percent residual sugar, didn’t have enough acidity to keep them from being cloying. The one exception was actually the sweetest wine in the group, the 2015 Hagafen Cellars White Riesling ($24) from Rancho Wieruszowski Vineyard in Napa Valley.

A much drier (0.7 percent RS) blend of 70 percent riesling and 30 percent gewurztraminer from New York’s Finger Lakes – the 2015 Goose Watch Riesling Gewurztraminer ($18) — had a great balance of racy acidity and a hint of sweetness. A very sweet (17 percent) riesling – the 2012 Pacific Rim Noble Wine Riesling ($39/half-bottle) from Selenium Vineyard in the Yakima Valley — maintained its balance, too, and was quite luscious.

There are exceptions, of course. The reliable Chateau Ste. Michelle Riesling usually has about 2 percent RS and is very good. And this observation about medium-sweet riesling generally doesn’t hold true when it comes to German wines. The Germans have a better handle on the whole interplay among sweetness, weight and acidity.

There was also some good news. I tasted some excellent wines. Here are several of them, in no particular order:

Among the red Rhone blends, there was the 2014 Ventana Vineyards Rubystone ($28) from the Arroyo Seco appellation, a 60-40 blend of grenache and syrah. The wine is spicy and dark, with blackberry, white pepper, smoke and firm tannins. It screams cool climate. The 2014 Eberle Cotes-du-Robles ($28), from the warmer surroundings of Paso Robles, adds mourvedre and a dollop of durif to the mix. The wine is lively and easy to drink, with bright berry, baking spice and fine tannins. The 2013 J. Lohr Gesture GSM ($30), also from Paso Robles, is powerful yet fresh, with juicy blackberry, roasted coffee and firm tannins.

V. Sattui hit a triple with three delicious zinfandels from three appellations. From the Russian River Valley, there was the 2013 Crow Ridge Vineyard Ancient Vines Zinfandel ($47), a spicy wine with rich, bright berry and medium tannins. From the Dry Creek Valley, the Mounts Vineyard Zinfandel ($37) has brambly zinberry fruit and spice and fine tannins. Finally, from Amador County, there was the 2013 Amador Ridge Vineyard Zinfandel ($36), a darker, denser wine, with lively blackberry, spice and roasted coffee notes.

I was pleasantly surprised by an inexpensive muscat from Australia, the 2015 Jacob’s Creek Moscato ($8), which is floral and quite sweet, with orange zest, orange blossom and nice freshness. A more serious – not to mention more expensive – sweet wine was the 2004 Patricius Tokaji Aszu, 5 Puttonyos ($45), which is absolutely luscious, with orange peel, hazelnut and great acidity to cut the sweetness.

You can view results from the competition here.