A lesson from Jos Biggs today.

And suddenly it’s hot! 

I knew it wouldn’t take long to go from complaining about the cold to moaning about the heat.

I’ve laid in ice cream stores and filled the ice cube tray, and in so doing I came upon a Thought. This is a seldom occurrence for me, but it threw up an ice cube related line of enquiry - Something you must have noticed, but I bet you’ve never thought about! 

Why is it that the ice cubes in your ice tray are bubbly, when the ice cubes in the drink adverts on the telly are clear?

Assuming you care, I will explain. Stand up straight now, you are going to be educated!

As anyone whoo has ever kept fish in a tank or pond will tell you water contains air. Not a lot of it, but if the water becomes de-aerated than the fish begin to suffer, and ‘gasp’ for air at the surface.

This air is held in solution in the water, so when water, for instance in an ice tray, is cooled, it comes out of solution and becomes bubbles.

The slower the water is cooled the less bubbles, as the air has more time to escape, but to achieve bubble-less ice reliably it would be necessary to pass the water constantly over freezing surfaces, until enough has been frozen. This is how commercial ice is produced.

This bubble problem is exacerbated by the habit that water has of freezing from the top down, this making it impossible for the air to easily escape once the freezing process has begun.

So ice in the drinks advertised on the telly is made from commercially made ice? Yes, possibly, but here’s the snag – the commercial is filmed under quite intense lighting, which is hot, and ice doesn’t like hot.

So unless it’s a one-off, really speedy shot the ice will begin to melt mid-shoot.

So what to do? Here you are, with your bottle of single malt, label prominently displayed and held by a professional dinner-suited Adonis, who pours a measure seductively into a glass containing two cubes of ice more translucent than the Star of Eärendil.

The camera pans in lovingly on the amber elixir, as the Adonis swirls it seductively round the glass, an action which emphasises the clarity and colour of the whiskey without the visual interference of bubbly ice. 

Fine, if you can get that done in one take. But what if Take 1 was not up to standard, Take 2 is required, and Adonis has already slugged the whiskey back, in anticipation of an early wrap?

Do the whole lot again? Not if you’ve been savvy!

This may come as a disappointment to some of you, but the ice usually used in drink commercials is actually carved Perspex.

And worse than that, the bubbles dancing merrily on the rim are usually very small glass beads!

But the whiskey? That’s real, surely? Ummmm….

I think I’ve burst your metaphorical bubble enough today. You’re looking a little flustered, dear. Better sit down and have a drink – just to calm your nerves.