The manager of Bairds Malt near Edinburgh emerges to meet the coach-load of postgraduates from Heriot-Watt University's international centre for brewing and distilling.
"Do you want a beer to start with?" the manager asks. The students hesitate briefly until Geoff Palmer, Heriot-Watt's professor of brewing, waves them towards the array of bottles, cans and sandwiches. "It's a fun trip. Don't tell anyone," he says.
"Ah, I see all the guys serving the ladies first." The female students eventually manage to fight their way past the male majority.
The hospitality from the maltings firm is a tribute not only to Professor Palmer's personal charm but also his reputation in the brewing industry.
An expert in cereals science and technology, Professor Palmer recently won the American Society of Brewing Chemists' award of distinction, commonly described as "the Nobel prize of the brewing world".
Today's field trip has been informally arranged by Professor Palmer to show the MSc students the malting process that transforms barley into beer. The Lothians are among the best barley-growing areas in the world, he says. They are flat with fairly sandy soil and enjoy long summer days and low rainfall.
The students already know that the barley grain is steeped for two days, germinated for five days, during which the starch turns into sugar and the protein into amino acids, and then dried in a kiln.
But the international group, which includes students from China, Japan, Greece, Canada and the Dominican Republic, says the visit gives them new understanding.
"We have a lot of industrial visits, which is very good. It makes the information in lectures more concrete," says one as they clamber up and down gantries to see massive steeping vessels and germination boxes, each section smelling more pungent than the last.
"This term we did all the vessels that are used, but you don't comprehend the size until you actually see it."
The students praise the humour and pacey style of Professor Palmer's teaching, but they are equally in awe of his expertise.
"People such as Heineken and Coors phone up Geoff Palmer about things, and his word is pretty much the law in the industry," one confides. "You feel quite proud you're being taught by 'The Man'."
They all agree that Professor Palmer is so enthusiastic about his subject that this cannot fail to rub off on his students.
"He keeps you on your toes the whole time. It's fantastic."
Professor Palmer's enthusiasm can lead to unexpected digressions. Outlining the central role that malt plays in the production of beer and whisky, he suddenly says that the Robert Burns poem "John Barleycorn" is one of the most accurate descriptions he has read of the preparation of malt for Scotch.
The popularity of Tennents lager north of the border sparks a discussion on Scotland's medieval links with the continent.
"Lager is a continental drink. The Scots have been drinking light coloured beer for centuries, while the English were drinking ales," he says.
"If you want to know this country's history, look at brewing. When the Scots signed the Articles of Union in 1707, the only thing they refused to sign was the malt tax imposed by the English. It was a direct increase on the price of beer in Scotland and would cause trouble."
The Scots were eventually forced to submit, he says, but Gladstone got rid of the "pernicious" tax because his ancestors had been barley-growing tenant farmers in central Scotland.
Even Pasteur comes into the conversation.
"Pasteur worked for the brewers. He was working on beer and wine. He heated two bottles, corked one of them and left one open. The open one became infected, and Pasteur came to the remarkable conclusion that changed the world, that there's something in the air that gets in, and that was bacteria."
His aim in teaching is not to astonish the students with his depth of knowledge, but inspire them to surpass it.
"If at the end none of my students has done better than me, it's not the students who have failed, it's me. Because if I don't produce students who do better than me, there can be no progress.
"The driving force in what I do is ensuring that what I know is passed on and can be built on." Students are known for spending plenty of time in the pub. Olga Wojtas meets a man who positively encourages them