Farage had to be whisked away in a police van after a crowd of about 50 young demonstrators, including activists in the radical left pro-Scottish independence movement, forced him to retreat four times.
The Ukip leader told BBC Good Morning Scotland: "The fact that 50 yobbo, fascist scum turn up and aren't prepared to listen to debate I absolutely refuse to believe is representative of Scottish public opinion. It is not.
"If this is the face of Scottish nationalism, it's a pretty ugly nation. The anger, the hatred, the shouting, the snarling, the swearing was all linked in to a desire for the union jack to be burnt."
Farage defended his decision to call the protesters "fascist scum", saying they had been "filled with total and utter hatred of the English and not prepared to engage in debate at all".
He criticised the media for failing to report "the excesses of Scottish nationalism and how deeply unpleasant they can be".
He did not blame the Scottish National party (SNP) leadership for orchestrating the protest, but told the BBC Radio 4 Today programme: "These people were supporters of Scottish nationalism – virulently opposed to the English, all sorts of suggestions as to what we could do with the union jack. I would like to hear Alex Salmond come out and condemn this sort of behaviour and I challenge him today to do that.
"If anybody from Ukip says anything on Facebook that is in any way homophobic or mildly racist you guys jump down my throat and demand that I condemn them and expel them from the party, which of course I do. It is about time Scottish nationalism was put under the same level of scrutiny. It has long been known in Scotland that there are some elements of Scottish nationalism and the SNP that are deeply unpleasant. This needs to be talked about."
Farage defended his decision to link the protesters to the SNP: "They were all campaigners for independence, they were all people who vote SNP. They were all united by a hatred of the English, the union jack and everything the UK represents."
He said he hoped Salmond did not hate the English. But he added: "I do think that here in Edinburgh there is such a level of intimidation that people are now scared to speak out. I have never been anywhere around the UK where I met people, even those with a completely contrary view, that I wasn't able to have a discussion or a debate with. This was just a hate mob and nothing less than that."
Farage was first forced out of the Canon's Gait pub after the landlord took fright as the protesters disrupted his press conference with shouts of "racist", "scum" and "homophobe". Out on the street, as the fingers pointed and taunts escalated, he was rejected by one taxi and turfed out of a second.
Then, finally, the harassed and ill-prepared handful of police officers was forced to push him back into the Canon's Gait, slamming its front doors shut, as the demonstrators chanted: "Nigel, you're a bawbag, Nigel you're a bawbag, na, na, na, hey!".
The etched sign above the Canon Gait's door reads: "Enjoy your visit".
With further verses of "Ukip scum, off our streets" echoing in his ears, Farage was bustled into a police van under the glare of television camera lights.
After attempting to argue back against the repeated accusations of racism and homophobia with protests of innocence, Farage finally had to admit his surprise. "We've never, ever, ever had this kind of response. Is this a kind of anti-English thing? It could be," he said to a reporter.
The protesters disagreed. Many said they were there to protest at Ukip's stance on immigration and the political backgrounds of Ukip's local council candidates; others were there to protest against his party's obscure economic policies. There was no violence, no punches thrown, no missiles lobbed.
Rachel, a young woman in a wheelchair who had wheeled herself on to the Royal Mile to blockade the second taxi Farage tried to take, said simply: "Ukip are just bullshit."
Some were independence campaigners, there to remind him of his nationality: after one, standing just a few feet from Farage, invited the Ukip leader to "shove your union jack up your arse", a flustered Farage said: "Clearly this is anti-British, anti-English. They even hate the union jack."
Farage had arrived at the pub in a buoyant mood, planning for his long-denied breakthrough into Scottish politics.
Compared to the near 25% support in the English local elections, the highest his party has ever polled in Scotland is 5.2% in the 2009 European elections; in many others, Ukip support has rested at under 1%.
The latest Ipsos Mori opinion poll, published in early May, found that just two Scots out of 1,001 would vote Ukip.
He was hoping for a quiet, convivial briefing – hopefully with pint in hand – with the Scottish political press corps. This was to be the official launch of Ukip's campaign for the Holyrood parliamentary seat of Aberdeen Donside – a seat held very comfortably by the SNP.
"We've proved we can get votes in Wales, England and Northern Ireland. We're still untested in Scotland," he said. "We've not had an opportunity to test Ukip policies with the Scottish people for a very long time." Asked about Ukip's chances, he was optimistic. "I wouldn't be at all surprised if we did quite creditably."
Less than 30 minutes after speaking those words, the MEP for South-East Counties was sitting hunched on the rear seat of a police riot van being driven off at speed, his plans to introduce Otto Inglis, Ukip's ever hopeful candidate for the Scottish parliament byelection on 20 June, forgotten.