Such explanations belong in the realm of speculation, along with the Loch Ness monster. This makes them splendid topics for sociable but unscientific conversation. Pub discourse is spoiled by too many facts: prejudice and hypothecation must rule. Another theory about Guinness, however, happens to be correct: ”It’s the way they pour it.”
In Ireland you have to wait for your pint. The drinker there will not accept it gladly if it comes too quickly. And then when he has it he watches it for a while, nursing his thirst, until the black liquid finally settles beneath the creamy head. The other week I found myself in a marquee at Gleneagles during the Scottish Open, as a guest of Sir Norman (now Lord) Macfarlane.
It was a day for the tent rather than the course. The rain, driven by a cool wind, had fallen all morning. Around lunchtime play was suspended by the thunderstorm that raged around. At our table none of us noticed, for our attention was held by Shaun Dowling, a Guinness director. Mr Dowling is a polymath. He was one of the few Guinness directors to survive the Saunders era.
To get through that unhappy period he distracted himself by writing books. He has among other things produced collections of essential phrases for businessmen, in French, German, Spanish and English. When Sir Norman went into Guinness as chairman, to preside over the cleansing of the stables, Mr Dowling proved himself a tower of strength, particularly in charting a course through the legal labyrinth. To his many talents he adds a theatrical impulse and the skills of a raconteur.
Hunched forward over the table, enjoying the impact he was making, his puckish eyes gleaming, he held in his hand the company’s new product, draught Guinness in a can, and discoursed on its scientific properties. For a start, the drink itself is identical in Ireland and Britain. The public refuse to believe it but that is the truth. In Ireland publicans use two gas cylinders, one of nitrogen and one of carbon dioxide. They tend towards the nitrogen because that produces the pint the public prefers.
More nitrogen makes the pint creamier but slower to pour. The head mostly consists of nitrogen. This is not as alarming as it might sound. Nitrogen forms nearly four-fifths of common air. It is, according to my dictionary, a necessary constituent of every organised body — a statement with which no regular stout drinker would quarrel. If the Irish drinker were to receive his pint instantly he would be highly suspicious of it. But his impatient British counterpart, not to speak of the British publican, will not wait so long. Here the pint is dispensed quite differently. The old kegs delivered to British pubs had twin gas chambers. But now the stout comes charged with nitrogen and the head can be quickly tickled up with carbon dioxide from the ring main. The secret of the new can is in its widget.
This is a little aluminium capsule, a chamber with a hole in it, attached to the bottom of the can. Before it is sealed a layer of carbon dioxide is injected which sits as a thin cushion of gas at the top. Pressure drives some of the stout down through the hole into the hollow cavity of the widget. When the can is opened, the stout flows out of the widget into the main body of the liquid. This movement sets up a chain reaction in the nitrogenous stout which stimulates a head as creamy as any you could find in Ireland.
The process works only when the can has been chilled. Guinness has patented the widget because it could have applications for other drinks, even for dispensing foaming pints of milk. Primed with this new knowledge, I returned to Glasgow and regaled my colleagues with it. They instantly assumed that I had been the victim of a hoax. A widget in a can of draught Guinness? Pull the other one. Well, it happens to be true.
But I don’t expect any more luck when I try the story out in Ireland. The new can is not yet on sale there and the most simple way of demonstrating the widget’s reality — emptying a can and then prising it open — will not be available. The myths, I am sure, will continue to be preferred. They give you something to talk about while you wait for your pint.