You could say it was the low point of my many years of drinking a lot of wine.
It's not that the wine was spectacularly awful (though some of it was pretty bad). It's the fact that it was produced in Turpan, the lowest point in China, down to 154m below sea level, making it the second- or third-lowest place in the world (there seems to be some argument about this).
But Turpan isn't just very low. It's possibly the hottest and driest place in China: average rainfall is 16mm a year and the highest temperature on record is 49.6C. It also gets cold, down as low as -24.4C. And it's smack in the middle of the great sandy desert which, under various names, stretches right across Central Asia.
As you approach the city across seemingly endless waves of sand, it doesn't feel like the sort of place you'd expect to be called The Grape Capital of China.
But, sure enough, there on the outskirts, at a place called Grape Valley, are great green fields of grapes - about 400ha in total - and the recent discovery of a vine in a 3000-year-old tomb suggests they've been growing here for a long time.
Mostly the grapes have been dried to produce raisins, and the traditional drying houses - built of bricks in a sort of trellis pattern so the air can circulate through the holes - still dot the landscape today.
But as far back as the Wei Dynasty, around 250AD, Turpan was being described as a land which "overflows with wine".
How can that be? I know grapes thrive on a challenge, but how can you grow them in a red-hot desert?
The answer lies in the amazing karez system of underground irrigation channels which for centuries has brought water from the surrounding mountains to the fields.
This arrangement, developed by the Uighur people at least 2000 years ago, enabled Turpan to expand from a small oasis on the Silk Road to a thriving agricultural centre.
Today, there are still about 400 karez systems in Turpan- the name means "well" in Uighur - providing more than 200 million cubic metres of water annually.
I was able to explore a 300-year-old system at the Turpan Karez Paradise, which is a sort of combination tourist attraction, karez museum and working horticultural farm.
As we walked through its pleasantly cool network of underground water channels, Bin, our guide, explained that it had its origins about 5km away in the surrounding mountains.
To build such a system, he said, the ancient Uighurs would climb up to just below the snowline and dig a well until they hit the groundwater, usually about 10m down.
Next, they would drive a tunnel about 100m down the slope and dig another well to meet it; this process would be repeated all the way down to the village requiring water.
The result, judging by the channels we explored, was a strong flow of cool, clear water.
"This one is very good," said Bin. "The water is so clean you can drink it."
Later, knowing what to look for, I was able to spot several lines of mounds marching across the countryside about 100m apart, marking the progress of karez systems.
The water they bring makes possible the cotton, melons, grapes and, of course, wines upon which Turpan's prosperity depends.
But what was the wine like? Needless to say, as soon as I heard that Turpan was the wine capital of China, I had to organise a bit of a wine-tasting.
Unfortunately, some people in the group I was travelling with thought the price of around $25 a bottle was a bit much - and you probably wouldn't be prepared to pay that much for wine of a similar calibre at a restaurant back home - but there was enough interest to justify a few bottles.
So with dinner at the Turpan Hotel that night we had two wines produced by Lou Lan, each labelled as "a masterpiece of world lowland wine", and a further red which disappeared before I could record the label.
The white, simply labelled as "dry white wine", tasted as though it had been too long in the bottle - though there were no dates to be seen - but might once have been reasonable. We drank it anyway.
The first bottle of red was also labelled simply "red wine", and not even Bin could find any mention of specific grapes, but was quite pleasant, despite having been served chilled - it got better as it warmed up.
But the second red was really, truly, awful, tasting more like some sort of chemical mouthwash than anything else I can think of - in fact, on second thoughts, it was the low point in my wine drinking career ... in every way.
At first thought it seems a bit ironic that the symbol of the lowest place in China is the highest structure around.
But when you see the beautiful minaret of the Emin Mosque soaring 37m above the flat, dusty plains, it's easy to understand why the local Uighurs chose it.
Built in 1778 by the local Muslim warlord, Emin Hoja, it was described by our Han Chinese guide as "a treasure of Uighur architecture".
The simple brick structure, with its patterns of flowers and waves, is just stunning.
Not long after it was built, the tower was cracked by an earthquake, but it has been held together securely since by an iron band.
And to judge from the line-up of worn carpets spread across the great prayer hall, with its wooden pillars, the mosque is still extremely well-used.
Getting there: Singapore Airlines operates 12 times a week between Auckland and Singapore and then onward to 62 destinations in 34 countries, including China.
Getting around: World Expeditions operates its Silk Road expedition from Beijing to Samarkand, including Turpan, in April, May, August and September. Ph 0800 350 354 for more information.
Jim Eagles travelled the Silk Road with help from Singapore Airlines and World Expeditions.