Day 2. On the bus nice and early, and a drive up the coast to Paso Robles, a large wine region that’s half way between Los Angeles and San Francisco, and one that is struggling to find its identity, a bit like an angst-ridden teenager.

We began with an overview, and a tasting of eight wines from four producers (two each). Established as an AVA in 1983, Paso Robles then had just 17 wineries. Now it has 32 000 acres of vines and more than 200 wineries. Interestingly, only 5 of the original 17 producers remain.

In 2007 the region was reorganized into 11 different sub-AVAs, and this was made official in 2014. There’s a conjunctive labelling rule, which means that Paso Robles needs to be next to the sub-AVA name on the label in at least the same size font. This is to keep the Paso Robles name in the forefront.

But what does Paso Robles stand for? What is its marketing message? At the moment, it’s one of diversity. We do a lot of things quite well seems to be the way the region is projecting itself to the outside world. And this is an accurate reflection of the situation: there’s an emphasis on Bordeaux red varieties, but Rhone red and white varieties are also strong. Then there’s Zinfandel, and Petite Syrah. And even Sauvignon Blanc.

Rather than focusing on the varietal mix, the marketing message that may have the most traction is that of the independent spirit and irreverence of the winegrowers here: the notion that this is a viticultural frontier land, where it’s not tradition that holds sway, but boldness and a spirit of adventure.

There are a few problems here, the chief one being high alcohol. Many of the wines, white and red, are in excess of 15% alcohol, and while this may reflect the sunny climate, it also speaks of stylistic choices. Winegrowers here could also do with a greater sense of perspective: when one said, ‘Paso Robles is one of the finest growing regions in the world,’ I was a little alarmed. Paso Robles is an interesting region with potential, but there’s a long way from here to being one of the world’s top wine regions. Let the wines do the talking.

What gave me lots of hope for Paso Robles was a visit at Tablas Creek, with founder Bob Haas and his son Jason. These wines are amazing. Bob came here in 1989 in partnership with the Perrin family of Beaucastel, and has created what is very possibly the best joint venture of all in terms of wine quality (Opus One is probably the most important symbolically).

The emphasis here is on the varieties of the southern Rhone, and Bob was drawn by the limestone in the soils. Jason too a chunk of this and demonstrated its water holding capacity: if you take this seemingly hard, impervious limestone and pour water onto it, it soaks it up like a sponge.

One of the tasks facing Haas was to get the plant material: many of the southern Rhone varieties simply weren’t in the country. So they had to import them. And then they had to graft them: for a while, they ran a nursery business selling these varieties to others. Now they have pretty much the full collection of authorised Chateauneuf varieties to play with.

Vintage here is a complex business with lots of small batches, as the harvest organization board shows.

We tasted the wines with Bob, who – at the age of 89 – is still sharp and engaging. It was a lovely experience.

The range of wines is deeply impressive, and I was particularly taken by the Grenache Blanc and Clairette, which were both lovely. Of the reds, the Terret Noir is super-interesting, very pale, and elegant, while the blends really bring out the best in the Mourvedre and Grenache, which on their own are very good wines but not complete wines.

This is a shining light in Paso Robles, and shows the potential of the region. This potential, is as yet largely unfulfilled.