The warning to liberal, well-meaning Britons is the latest twist in a saga which began last month when John Platter, the celebrated South African wine writer, lambasted the Cape's all-white winelands establishment on BBC Radio 4 over its plans to share out 2bn (about pounds 285m) to 5bn rand of assets, accumulated during the apartheid years, among 4,700 white farmers. Mr Platter exposed the industry's exploitation of tens of thousands of Cape Coloured labourers and its barbaric use of political and criminal prisoners as slave labour until the early 1980s. Yesterday, at his vineyard near Stellenbosch, he was taking nothing back. In a letter to the Afrikaans newspaper Die Burger last week he suggested the industry's restructuring - or privatisation - amounted to "looting" and denounced the move as out of step with attempts to redress the injustices of the past.
But he was furious at Die Burger reports yesterday associating him with suggestions in a British Sunday newspaper that a European boycott might be in order. "A boycott would be completely counter-productive to producers and labourers," he said. Worse, the boycott call obscures the real issues and gives white owners somewhere to hide.
At home, the KWV, the cooperative of vineyard owners which has proposed its own privatisation, has condemned Mr Platter and his wife Erica as traitors. Neighbours have burned copies of the couple's annual wine guide - the bible on South African wine - and local farmers are promising to mount their own boycott - of next year's Platter guide.
At the centre of the row are tens of thousands of Cape Coloureds who, three years after the end of white minority rule, still toil in the vineyards for as little as R100 a week - the price of two bottles of South African red or white in a British supermarket - and a daily dop (drink) of half a litre of wine.
According to Grant Twigg, the general secretary of the Farm Food and Rural Workers Union, also a Cape Coloured, the daily wine quota keeps the vineyard workers docile and too dependent to leave the industry. Alcoholism, he claims, is deliberately encouraged by many farmers. He, like the Platters, argues that the workers have a right to share in the benefits accrued during the apartheid years.
Since the early 1990s, he says, the industry has seen some improvements but the vast majority of workers are still appallingly exploited, despite 6 per cent annual growth in the domestic market and a 38 per cent increase between 1995 and 1996 in overseas sales.
But he too rejects the idea of an overseas boycott. "During the years of apartheid my union supported sanctions," he said. "But in this case a growing industry and particularly its workers would suffer."
The Platter camp is attempting to force KWV to hive off a significant portion of the apartheid-era assets to transform an industry run by whites for whites. They want to bring blacks and Coloureds into management and ownership.
So far they have succeeded in persuading Derek Hanekom, the Agriculture Minister, to halt KWV's privatisation plans while an inquiry takes place. They argue that this is a rare case when doing the right thing is also good for business.
With blacks involved in the business, the pleasures of wine would be filter though to the black community, and boost home sales. That is the dream of Jubalane Nstangase, currently the only black manager in the Cape winelands and a one-off in the South African wine trade.
Raised in Soweto, he learned the wine trade while in exile in New York.
He began importing South African wines to the US in 1992 and finally returned to his native country in 1995, where he was hired by the white entrepreneur Dick Enthoven, owner of the Spier Wine Estate.
Mr Nstangase was employed to create a few waves, but like some "token" blacks taken on by big business, his mouth has proved bigger than his boss probably anticipated.
This week the heat is on. The Afrikaans papers is crammed with criticism and still Mr Nstangase cannot stop talking. On a Sunday - a big day for visitors - on the Spier estate, Mr Nstangase sticks out; the only other blacks are serving in the wine shop or trailing an endless stream of little blonde girls around a large lawn on ponies.
The wine industry he describes is rotten with racism. He came back to South Africa to realise a dream. "When I was importing, my American customers always asked the same questions - how many blacks were employed in management of estates, how many black owners were there, how many black exporters were there?"
Of course there were none. He came home to change that; to open the business and the product up to blacks. Much is made of professional whites leaving South Africa. Blacks who returned with skills, only to be hampered by white intransigence and invested interests, are somehow invisible. "If you mention black empowerment in the wine industry, everyone cringes," he says.
He is angry at recent comments by a KWV official that wine is always a white-dominated sphere, in any country. "That's just the sort of thing they used to say when I was growing up. It was the excuse they gave for not paying whites and blacks the same wages. "Look around," he added, gazing across the lawn towards another smart restaurant devoid of black visitors. "If I didn't work here as a black man I would never come in."