Kohl the pear was my first thought when the BBC asked me to make The German Giant. I spent a year at a German university in the late 1980s, where to have expressed anything other than derision for Kohl would have got you labelled as a raving right-winger faster than saying you fancied Eva Braun. So widespread is such prejudice that Kohl's opponents have fatally underestimated him for years.
Six months travelling the world interviewing the German Chancellor's famous friends showed me how limited my view had been. The culmination was three interviews with three former world leaders in three days: America's George Bush, Russia's Mikhail Gorbachev and Israel's Shimon Peres. Despite their very different political outlooks, I was struck by the way their praise for Kohl was so consistent. Whether through the cold blue eyes of right-winger Bush or the sad sagacious stare of the left's Peres, Kohl was seen as a man worthy of great acclaim. Only when we started interviewing people in Germany did the balance swing back: clearly this ex-footballer's away performances have stood the test of time better than his record at home.
Germany's top satirical magazine Titanic frequently features Kohl on its cover. Celebrated lines have included: "The reunification is invalid - Kohl was doped" and "Buddhism bizarre - Kohl threatens with rebirth". As Titanic's editor Oliver Schmitt told me: "In November 1982, Titanic invented the pear as a symbol for Kohl because in German pear has a double meaning. It means the fruit, but also a big empty space, like a big head, and as we know Kohl's head is really big. Our first cover was `The pear must stay Chancellor forever'."
That, of course, was a joke, but 16 years and four election victories later, the pear is still in power. Now it seems more like prophecy than mockery.
After hearing his praises sung by world leader after world leader, it became clear that the man who outwardly has the political charisma of a pair of worn carpet slippers is used to having the last laugh.
George Bush was certainly impressed. "I found that ... personal diplomacy is important. It's not going to stop someone being communist or they are not going to stop being against regulation, but if you know someone personally, a warmth builds up, one trusts the other. One sees one's word is good," he told us. "With Helmut ... we had an easy kind of humour back and forth, that made it fun."
Former British prime minister John Major also used that F-word: "The meetings were fun, they were enlivened with jokes, with anecdotes, with portraits of people we were discussing. We dealt with the issues of course, but it was very relaxed and very enjoyable." Major vividly remembered Helmut's classic culinary weapon in his charm offensives - Saumagen. "Helmut had pig's bladder. He very generously offered me pig's bladder and I gently declined. I think I had lamb chops, as I recall. He had the pig's bladder and as I recall had a substantial helping of it." Major was obviously overwhelmed by the pleasure of remembering this culinary opt-out, because Helmut's favourite dish actually consists of pork and potatoes stuffed into a pig's stomach, not a bladder. Probably still a bit exotic for John Major, who could not resist a dig about Kohl's legendary appetite: "We had tea, I remember, perilously close to lunch."
Kohl's baroque eating habits may have astonished the abstemious Major, but they got good marks from the Russians, who tend to stereotype Germans as cold, austere Prussians. Mikhail Gorbachev told us: "He's a man with a heart, not a cold rational German mind. No, this is a man of big feelings. I think that even his love of having a good drink - it's also a sign of loving life." The former Russian president laughed heartily at the memory.
Former Israeli prime minister Shimon Peres is another fan, but he was intimidated by Kohl's enormous size. "You don't feel at ease in his presence, I mean he is so huge and so great. You feel you are a miniature." Peres was also subject to the culinary charm offensive. He told us: "He can be very brotherly, very comradely."
For the German electorate, Oliver Schmitt believes Kohl's physical size has been an advantage: "His success is in just being there. He's a steady object in a world of change. He's like a rock in the sea, that will be there forever." The elections on 27 September could change that. Kohl's Social Democrat opponent, Gerhard Schroder, is giving the Chancellor a run for his money. The opinion polls are not looking good for Kohl. More importantly, perhaps, nor are the cartoons.
In Bonn Professor Walther Keim has collected 20,000 Kohl cartoons for the parliamentary press archives that he heads. The pear, he reveals, is going out of fashion. "The image of Kohl has always been very constant, but interestingly he is being drawn more life-like, as more bitter and frustrated." He has even been shown as his arch-enemy Margaret Thatcher.
This is bad news for Kohl, because as Keim reveals: "The pear was a bonus, on a psychological level, he gained in sympathy with middle-class Germans. Most Germans are fat and they understood that he could not keep his weight under control. Cartoons are optical itching powder, and cartoonists are social seismographs."
If there is one thing that politicians and satirists are agreed on, it is that one should never underestimate Helmut Kohl. So we'll have to wait and see who has the last laugh on election day. In the meantime, let the cartoons roll.
Frederick Baker produced and directed `Helmut Kohl - The German Giant', to be shown on BBC2 on Saturday.