Take your hols in Scotland and you'll find that your cottage kitchen has three taps: hot, cold, and Irn-Bru. Other chilled beverages are produced, however, from the mighty AG Barr company. Nip into Teighness Stores on Shore Road -- in the village of Arrochar on the bonny banks of Loch Long -- and you'll find not only the 'Bru but also the non-hellish 'ades, viz lemonade, limeade and cherryade, and maybe a cream soda or two. Nestled among these, however, is the grail: Barr Red Kola.

I'd popped into that particular Premier Stores for milk and bread. Fortunately I remembered those essentials and didn't just return with the red stuff. Plonking down my 330ml cans on the counter, the smiling lady felt obliged to tell me that these weren't included in the Barrs three-for-a-pound promotion: each can was daubed with "Special Price 45p". If required, I'd have forked out a quid per tin.

Part of the draw for RK, as we'll lovingly call it, is that as the Wikipedia page says, it's "virtually impossible to find in English shops". Now, it was my very good fortune to stumble across a stash once in a local Ipswich corner shop. They had it for a month or so, then it disappeared like a milk tooth left in a glass of Coke. Thinking back on this, I may have dreamed that whole episode after passing out during a marshmallow sugar rush.

We made sure to bring some back south of the border, Eldest ringing ahead from Glasgow on our final day to ask someone to clean out the stock in that Arrochar store. In Dumbarton Asda -- always wanted to write that sentence opening -- we added to our supplies with a 99p two litre bottle. Sweet. Literally. While there, we also came away with another quintessential foodstuff, a pack of Tunnock's Teacakes. Not the regular ones, mind, but the new dark chocolate variant. Yum. Search now begins for the elusive Tunnock's wafer creams.