IT may not boast Oompa Loompas, everlasting gobstoppers or golden tickets, but Scotland's most famous chocolate factory has become overwhelmed by sweettoothed visitors.
The public demand for tours of the Tunnock's plant is such that a year-long waiting list has now been put in place.
The free tours are never advertised, but word-of-mouth recommendations from chocoholics has meant they are blocked solid until late in 2009.
The unexpected sugar-rush of tourists has left a bittersweet taste in the mouths of the Lanarkshire-based biscuit giants. So much so that they are appealing to Caramel Wafer fans to think twice before requesting to come to the factory.
Tunnock's has grown from being a small family bakery into a national confectionery icon which employs 700 staff and produces more than four million biscuits every week.
Despite this, the owners of the Uddingston firm, are bemused at becoming an unlikely tourist magnet.
Spokesman Fergus Loudon said: "We certainly don't promote the factory tours in any way.
"They have evolved gradually through word-of-mouth until we have reached the stage today where we are fully booked for a whole year in advance.
"We run the tours as a goodwill gesture to our customers and are happy to do so, even though it costs us money."
The firm runs weekly tours throughout the year, but restricts the annual number of visitors to under 10,000. We just don't have the resources to cope with any more.
"We have got our hands pretty full so unfortunately we have little choice but to reluctantly turn people down or suggest they join our ever-growing waiting list."
Visitors to the building which dominates the douce community, on the outskirts of Glasgow, pass through a reception door which bears the words: "Still a Family Business".
Visitors are then shown the artery-like network of pipes which pump 15 tonnes of chocolate through the factory on a daily basis.
On a mezzanine level a further 40 tonnes of caramel is produced daily, to a top-secret recipe.
The famous wafers are produced on conveyors and roll continuously from their ovens in hefty 16x12in slabs, while countless marshmallow teacakes and snowballs pass under Wonka-esque waterfalls of chocolate.
Loudon remains modest about the mouthwatering displays. "It is not done as a commercial tour in the Baxter's mode. Visitors
get a full tour of the premises and at the end we give them a couple of packets of biscuits and a cup of tea. There is no company shop or anything like that."
The firm, which was founded by Thomas Tunnock in 1890, attracts visitors from across the UK and beyond.
"There have been a few people from North America coming to visit the factory and we are happy to fly the flag for Scotland and home-grown talent.
"We get all sorts of groups, from solicitors to the Women's Rural Institutes.
"A lot of students also come along and we keep in touch with them fairly regularly. Today's students are tomorrow's buyers so we are very keen to keep them happy."
The firm appears to be succeeding in that task as St Andrews University's Tunnock's Caramel Wafer Appreciation Society has been running continuously for the past 26 years.
It raises money for charity as well as having the goal of "Introducing others to the happiness that is that first taste of the Tunnock's Caramel Wafer". Dundee University's Tunnock's Teacake Appreciation Society was founded more recently but already boasts more than 290 members and its very own, supersized "pimp my snack" replica teacake.
Chart-toppers Supergrass visited the Tunnock's factory in 2005. And the tours have been lauded by the Scottish tourism support group Pride and Passion as a unique Scottish experience.
In 2006 Tunnock's clinched a subliminal advertising deal with Emmerdale, the television soap. Its snacks are displayed in the village shop of the fictional Yorkshire town.
Scotland's most famous confectionery empire was founded in 1890 when Thomas bought a shop in Uddingston for 80 and started a bakery business.
More than a century on, the family-owned firm churns out millions of teacakes, caramel wafers, snowballs and caramel logs each week at its factory in the South Lanarkshire community.
It first exported its products in 1957 and now services around 30 countries. Its products are particularly popular in the Middle East, with the firm reporting strong sales in Saudi Arabia and Kuwait.