“How far along is it?” I always ask of the maltster on duty, as if I’m enquiring after an expectant mother. If the barley’s hard as nails, it’s likely not been long on the floor. At this point, the wet barley seed is just awakening from dormancy. After the grain has sprouted (that’s called ‘chitting’), a rootlet will develop, and if it’s chewable under decent pressure, without cracking your tooth, that means the seed is germinating and a complex process called ‘modification’ has begun.

During modification, enzymes break down the net of cell walls and protein holding the all-important starch granules hostage, but it’ll still be a while until all of them are soluble and accessible for later conversion (by yet more enzymes) into fermentable sugars during mashing, with secondary conversion taking place in parallel with fermentation in the wash backs. However, if there’s a decent little rootlet and the grain crumbles pretty much the moment it touches enamel, we know the barley is now malted.

At this point, we call the malt ‘friable’ (meaning ‘easily crushed under pressure’), and the malt’s friability is a good indicator of how well-modified it is. Under-modified barley will deliver a poorer yield, but over-modification can cause problems too. I’ve been told that it’s the relative inconsistency in the level of modification across a batch of floor-malted barley (relative to the uniform modification of the commercial variety) that helps give the whiskies it becomes added aromatic complexity and mouthfeel.

I was chewing this thought over while standing calf-deep in barley at Bowmore Distillery on Islay a few months ago, during a visit to preview the recently revealed Sherry Oak and Appellations collections, and the bottles’ sleek, sea dragon-adorned new look. Bowmore has long made a feature of its floor maltings, and it’s reassuring that they hold a special place in the heart of distillery manager David Turner, who is vocal in his conviction that floor-malted barley is key to the distillery’s famously complex, tropical, and gently smoked style.

I’ve never held truck with the arguments of those particularly hard-nosed whisky fans who claim floor maltings producing only a proportion of a distillery’s requirements (as is the case at Bowmore, Laphroaig, Kilchoman, Highland Park, et al.) are merely a marketing tool to charm visitors. It’s always struck me that there are easier and cheaper ways of putting on a good tour! Nevertheless, it was only fairly recently that I began to truly appreciate the role even relatively small proportions of floor-malted barley can play in flavour creation.

Specifically, I began thinking of how much these mixed mash bills of floor- and commercially malted barley remind me of bourbon distillers’ use of rye and wheat as ‘flavouring grain’. My theory grew into a conviction during side-by-side comparisons of single malts from the same distilleries made from varying proportions of floor- and commercially malted barley. While each distillery’s whiskies shared a unified style, in all cases there was an undeniable uptick in both mouthfeel and complexity as the proportion of floor-malted barley increased, though all other production parameters stayed the same. From what I hear, this has not escaped the notice of Bowmore’s owners, Suntory, for whom floor malting is a key focus not only on Islay, but at Glen Garioch, Yamazaki, and Hakushu. I suspect this phenomenon also plays a role in the complexity of Kilchoman’s truly excellent malts.

Along with the renewed interest in heritage varieties and speciality malts, I hope that more distillers will explore floor malting as an avenue of flavour creation in the years ahead so we can all bite barley a little more often.