Whisky buff to whisky bluff: what on earth is chill haze?

If you’re anything like the team here at Whisky Foundation, you’re a fan of beer as well as whisky. If that is the case, then you might have noticed the recent trend of hazy IPAs cropping up all over the place.

They’re the current ‘in-thing’, and for good reason: they have enhanced aromas, are smooth and creamy and have a reduced bitterness that you sometimes get with an IPA.

Does that sound familiar? (cough, independent bottling, cough)

Now, we’re going to sound like a broken record. But it’s no coincidence that craft beer is now discovering – or at least, craft beer drinkers are discovering – things that drinkers of independent bottlings have known for ages.

As we’ve said before (several times), craft beer and whisky are, in very many ways, very similar.

And this trend towards hazy beer is very similar to the argument against chill filtration – the haze (in whisky’s case, it is known as chill haze) is a purely aesthetic concern. Sure, it might not look as pretty when you upload a picture to Instagram or Facebook, but the haze adds flavour, depth and character to the drink.

Still with us?

No.

Let’s break a down a little bit.

First of all, what on earth is chill haze?

Good shout. Let’s deal with the basics first.

When it comes to whisky, there are certain elements that get us very excited indeed. They’re the basic elements, sure, but they’re also key to a great whisky.

If you get the aroma, the taste and the texture of a whisky just right – it’s one of the greatest experiences on the planet.

The problem is, these attributes come from compounds within the whisky itself.

The vast majority of these compounds are soluble in the water and ethanol that make up the whisky. However, some of these compounds – specifically, the esters, proteins and fatty acids – are only soluble at warmer temperatures.

Once the whisky cools, these compounds stick together to form small particles (known to those in-the-know as micelles).

These particles scatter the light as it hits the whisky, causing it to appear cloudy. This cloudiness is known as chill haze.

OK, so it’s just a slightly hazy whisky? 

Pretty much, yep.

So why is chill haze such an important thing?

Well, it’s not so much that the haze itself is important, but what the haze signifies.

It signifies that the whisky hasn’t been chill-filtered and that all the esters, fats and proteins are there to give the whisky that extra oomph.

That extra ‘something’ that makes it special.

Hold on, hold on. What’s chill-filtration when it’s at home? 

Unsurprisingly, chill filtration involves chilling the whisky to remove all the compounds that clump together to cause the haze.

Single malts are chilled to zero degrees Celsius to make sure that the micelles form.

Then, the whisky is pushed through a succession of metallic meshes or paper filters. These meshes and filters collect the clumps of particles and remove them from the final product.

This is usually done to ensure a consistent, aesthetically pleasing product.

However, it also removes the things that take a whisky from something pretty good to something special.

Still not making any sense?

We’ve compared independent bottlings to music before, and the analogy works again here.

Remember as a teenager, having a favourite band?

They had probably released a scratchy demo or first album, but you loved every aspect of it.

The way the guitars play off each other, the driving bass lines, the clever lyrics… It was really something, right?

Now, if you were unlucky enough to witness them signing to a major label, you might have experienced a chill-filtration of their sound.

Perhaps the guitar lines were tightened up a bit, their lyrics made a little more wholesome or the production made them sounds polished and tight rather than rough and raw.

The little things that made them extra special had been removed to make them as appealing to a mass audience as possible.

And although they were still a great band, they’d lost that special something.

They’d lost the thing that made them really special.

That’s what the chill haze is – a sign that the whisky still has that special something.

Now, if you’ll excuse us, we’re off to dig through our teenage record collection and weep.