He has been a regular visitor to Hong Kong and Japan, and has helped educate customers, who might previously have been interested exclusively in Bordeaux, about the subtleties of Burgundy. But he is also interested in finding wines in Asia which might make good additions to the Berry Bros & Rudd list.

On his last trip to Japan, he visited the Koshu vineyards in Yamanashi, he plans to go to Hokkaido next. The idea is to build up a profile of seeing and understanding vineyards in Asia, he said on a recent visit to Hong Kong and Shanghai.

From Shanghai, he took a side trip to Yinchuan in the Ningxia Hui Autonomous Region, where wineries are operated by the Changyu Pioneer Wine Company, LVMH and Pernod Ricard.

"I want to go to the vineyard areas, see what's planted, see what the soil looks like, and get a feel for how the producers on the ground look at it," he said.

"If there are good wines to be had in China we should know about them."

Berry Bros already sells Chinese wines, made by Changyu in Liaoning near the border with North Korea, and by Austria's Lenz Moser under the auspices of Changyu in Ningxia.

Morris was optimistic about what he would find, although he acknowledged that much hearsay about the Chinese wine industry is negative.

"Some of these things may be urban myths, and they don't worry me. What I want to know is, is it genuinely possible to make fine quality wine - exciting wines which can take their place in the world line-up - in different parts of China?" he said.

If it is, it is not yet clear where. China's coastal areas are too humid for the cultivation of grapes for fine wine. By contrast, most inland areas are too cold for vines to survive the winter, unless buried and uncovered in spring - a process which not all of them survive.

"The humidity is always going to be a problem for grape quality and there is no way round that. The banking up in winter may have some negatives but there is no reason why it should be a problem for the wine, which is defined by the quality of the growing season.

"It will make it difficult to keep vines in the ground for as long as you would want to keep them in. You may have to renew them more often than you want. But somewhere in this country there is going to be the right place," Morris said.

He was already familiar with Chateau Changyu Moser XV, and so had some idea of what to expect in Ningxia:

"A lot of wines which are perfectly competent, but are winemaking [as opposed to terroir-defined] wines, and one or two which will make me think, 'That's good, that's interesting'."

The prediction was sound. As well as tasting wines by the big producers Morris was able to assess those of boutique wineries Silver Heights and Jiabeilan. He found a number of competent wines which, with "some tweaks towards better ripeness and less oak influence would considerably increase the strike rate of competent to very good wines". But there was no rough diamond, which suggested that greatness might be possible, he said.

"The purity of fruit and precision in the Jiabeilan wine, Helan Quigxue Vineyard 2011 - which was slightly underripe - and the suavity and grace of Silver Heights 'The Summit', which needed a touch more precision and definition, were the highlights. But I enjoyed the balance and cheerful fruit of the Moser Family cabernet sauvignon."

He did not find any new wines for Berry Bros - partly for reasons of price. The wines he tasted that were of an appropriate quality were mostly priced to make them uncompetitive outside China.

The visit has encouraged him to explore further, as has the quality of the Chateau Changyu Golden Valley Ice Wine from Liaoning. "I really did like the ice wines that Changyu make up near Korea. That's going to work, because the conditions are right, but for 'normal wine making' they haven't yet found the areas that have the potential to be brilliant - unless they turn out to be in Yunnan," he said.

Yunnan is likely to be the next vineyard area he visits on the mainland. Conditions there seem more promising, and Jancis Robinson, who has visited a Moët Hennessy winery under construction in Deqin County near the Tibetan border, believes the area has potential, although its inaccessibility poses logistical challenges.

Moët Hennessy also makes Domaine Chandon wines in Ningxia, which struck Morris as more realistically priced.

"I think the Domaine Chandon business is quite promising given the price point at 138 yuan (HK$175) for the white sparkler and 165 yuan for the pink sparkler," he said.

Very little of Ningxia's wine is intended for export, but that could change in the future. "Up to now, almost everything produced has been sold within the domestic market, which explains the focus on red wines, fairly noticeably oaked, and presented in heavy bottles," said Morris.

"But consumption has declined markedly, especially since the anti-corruption moves of the government, attempting to cut out bribery and the excessive consumption associated with the 'ganbei' toasts at official dinners.

"Is the next move to look for overseas markets? If so, there is a fair amount of fine tuning to be done, and it looks as if there is an appetite to do so."

Although he thinks Ningxia has the potential to do better, Morris said any great Chinese wine is likely to come from elsewhere.

"There is an imbalance between the quality of the fruit which makes up the raw material, and the ambition of the region to be China's premium wine production area," he said.

"The visit reinforced my view that if China is to produce something consistently world class, then it must come from a region which escapes ambient humidity, yet doesn't require burying the vines underground in winter. Could that be Yunnan? I am impatient to find out."