Brown's wine investment has served him well. His wine stock has significantly appreciated, and he has also gained from his investment in a wine fund managed by Wine Asset Managers. The fund has risen 29.3 per cent this year and 61.8 per cent since its launch in 2006.

The Liv-ex Fine Wine 100 Index this year increased at a pace twice that of last year, climbing 31.9 per cent by October 31. The benchmark comprises high-end wines, mostly from Bordeaux, Burgundy and Champagne and from Italy.

But according to Brown, wine investment is only a way to hedge his costly drinking habit - when prices increase, he has to shell out more for a good drink, but the wine fund rises as well, offsetting higher expenditure with higher returns.

The fund manager started to collect wine in the mid-1980s and hasn't stopped. His best return came from a case of 1947 wine he bought for about GBP20,000 years ago. Four years ago he sold it for GBP75,000. 'That's almost GBP1,000 a glass!'

If he had held onto it, he says he would have made even more because Chinese buyers have begun to flood auction houses and wine merchants' offices these past years, pushing fine wine into bubble territory, particularly in the case of Lafite Rothschild. This is why Schroders has no plans to launch a wine fund, because current prices are just unsustainable.

'The Chinese buying has dramatically boosted wine prices, particularly those of Lafite. But young Lafite is in fact unlikely to be very good. The market has been distorted and prices are all over the place.' A tranche of Lafite 2009, which is still in the barrels at the chateau, was sold recently for four times the London rate for a case. A Lafitte 1982 was sold for HK$860,000 a case - double the already high London price.

'I wish someone would tell the Chinese buyers that they could have got the same wine much cheaper had they just called any wine merchant in London,' Brown says. 'Wine tastes like vinegar if you find out you have paid four times more than it ought to be.'

Ask Brown about the outlook for the market and you'll get a fund manager response: 'What can go up can also go down.' Complete with a fund manager disclaimer: 'Past performance is no guarantee of future prices.'

Investors should pay attention to some important aspects, he says. First, the lack of transparency in the market. A good case of wine that may be sold for GBP660 in London may be sold at GBP560 when a different label is stuck on it. 'This shows the inefficiency of the market information in case of wine.'

Those who wish to invest should carefully calculate the cost, because there is a wide spread between buy and sell prices.

The cost of storage and insurance can be considerable. So someone who has purchased a case of wine at GBP1,000 and sold it for GBP2,000 in 10 years may only have made a profit of GBP600 if the storage and insurance costs are factored in. Wine investment thus entails much higher costs than stocks and funds.

And then there is always the chance of wine prices going down, linked as they are to the vagaries of the economic cycle and wider market conditions. Brown recalls a particular case that was priced at GBP1,200 by wine merchants in 1999. The dotcom bubble burst soon after, and wine, like everything else, fell victim to the bearish aftermath.

Brown, adopting the usual fund manager strategy of buying low, picked up the case in 2003 for GBP700. He still has the case, which has appreciated to GBP3,000 now, having recently survived a bear attack following the financial crisis. The moral of the story: buy and hold works in wine as well, and those looking for a fast buck should look elsewhere.

In the current bubble in wine prices, how do drinkers and investors make sure that they are paying the right price?

'Luckily the world is a big place so we can search far and wide for good wine at a good price,' Brown says. His advice: First, do not insist on first or second growth. Venture further and the chances are you will get more reasonable prices. Second, do not stick to big brands. Some of the wines were ranked more than 150 years ago and both the chateau owners and winemakers may have changed since.

'Some new makers, such as those in South Africa, make very good wine at reasonable prices,' Brown says. A South African wine made with Bordeaux grapes would come at GBP17 a bottle. A similar French wine would cost GBP50.

The currency issue should also be considered. Australian winemakers, Brown says, are struggling now that their wine has become costlier as their currency has risen steadily against the US dollar. In US dollar terms, Australian wine has become far more costly than a couple of years ago even as its quality has remained unchanged.

And just like other investments, people should do their homework. Brown recommends articles of Professor Orley Ashenfelter. 'Ashenfelter is a well-respected economic professor at Princeton University. But he is so crazy about wine that he has created a model to predict the quality and price of a wine by linking it to the weather.'

Ashenfelter believes temperature and rainfall affect the quality of a wine as hot weather makes grapes ripen quickly, while dry weather concentrates the juices in grapes more. As a result, wine made in a hot and dry year will mature better.

Ashenfelter has tested his equation on Bordeaux with vintages from 1952 to 1980 and found out vintages that yielded a higher score in that equation had also commanded a higher auction price.

But if you do not want to burden yourself - or your children - with the complexities of mathematical calculations, Brown suggests a simpler way of treating your wine investment: 'Drink it.'

Price comparison

Alan Brown says to watch out for quality New World wines

A South African wine using Bordeaux grapes would come at GBP17 a bottle, he says, but a similar French one would be: GBP50