A couple of months back your correspondent was offered the opportunity to interview Rande Gerber, one of the partners in the "small-batch, ultra-premium" Tequila label Casamigos. Gerber is a significant individual is the United States lifestyle industry, owning restaurants, bars and lounges across the land. He is also the co-creator of the super-premium Puerto Rican white rum Caliche.

There are two other partners in Casamigos: luxury property developer Mike Meldman and a certain writer, actor and director named George Clooney.

But I declined the invitation. Not that I'm averse to star-powered spirits or other libations, having written positively on the pristine vodka of Dan Ackroyd (Crystal Head) and delicious Tuscan reds of Sting and Trudie Styler (Il Palagio). Hey, I even once greased some words over Olivia Newton-John's Koala Blue wine label.

It was just that at the time of the offer I'd yet to clap eyes and mouth on the Casamigos juice itself. But now I have tasted both the Casamigos Blanco and Reposado in line-ups along with my tequila benchmarks including Herencia Mexicana Blanco (n/a) and Oro Azul Reposado ($110), and they are both beautifully balanced spirits. The Casamigos Blanco (95/100, $79.99) is packed with fruit flavours: almost Poire Williams pear-like and pure; super-intense and with dabs of white pepper on the tongue. The Casamigos Reposado (94/100, $84.99) is distinctly fudgy sweet oaky after resting in wood for seven months, but is also pepper sprinkled and has just the right amount of chewiness. It's like the classiest patisserie's vanilla slice (with alcohol and a sprinkling of white pepper).

If only...

So I sort of wish that I'd accepted the offer now. I could have asked Gerber what he and Clooney think about that wall which is going to be constructed, separating their home country from their Mexican residences or casa amigos ("friends' house", after which the tequila is named). But I'm guessing they'll be flying over the wall rather than travelling on the vintage BMW and Honda motorbikes they're astride in the image attached to the Casamigos hessian gift bag.

I'd also like to have asked about the "small batch" tag which nigh on every producer of fine spirits bandies about. With Casamigos available throughout the United States, UK, Canada, Hong Kong, Spain, Italy, Bahamas, St Barths, Cyprus and now in Australia, New Zealand, Fiji and surrounding islands, there must be a whopping amount of small batches bottled.

Although there's plenty of info on the Casamigos website about the Blue Weber agave piñas roasting technique and fermentation process, there's not a lot about distillation, small batch or otherwise. So another question I would have asked might have concerned the size and structure of the stills employed.

Stills, you see, play a vital role in the style of spirits emanating from them. The still is component of what you might call cellar terroir, where the place a distillate is created and matured has a distinctive influence on its flavour. It is as important as the raw material from which any quality alcoholic beverage is crafted. Much is made, for example, of the Victorian still recommissioned a couple of decades ago to bring Plymouth Gin back to life, and I'm so glad that it was as it remains an understated, restrained gin benchmark (94/100, $55).

Small-batch stills

There are two primary stills at Four Pillars in Healesville, Victoria. The inaugural still, Wilma, named after head distiller Cameron Mackenzie's mum, holds 450 litres. The second, Jude, named after partner Stuart Gregor's mother, is 600 litres. Each distillation takes around seven hours and the runs produce around 480 to 580 bottles respectively. So genuinely small batch.

Wilma and Jude are seven-plate copper pot stills with botanical baskets sourced from Carl of Germany. They are of considerable beauty, as is the baby still Eileen, with a capacity of just 70 litres. Eileen is employed, Mackenzie tells me, for "some fun distilling classes, but overall it is used to trial new botanicals and recipes". It has a botanical basket and a three-plate column. So micro-batch.

The current bottlings of the distillery's flag bearer, Rare Dry Gin (94/100, $75), are impeccable: candied peel, some Turkish delight, piney and bracing. The Spiced Negroni Gin – balsam, cardamom, anise – is simply sensational (96/100, $85). The extremely small-batch Australian Christmas Gin ($95), at just 3000 bottles, is a spirit star of wonder. Let's pray it becomes an Aussie Christmas tradition.

Definitely fitting into the micro-batch category is the Prohibition Liquor Co Bathtub Cut (94/100, $115), launched back in July. Thus far there have been five batches of between 180 and 190 bottles (each bottle is numbered accordingly). It's bottled at a whopping 69 per cent alcohol per volume, so it's a potent spirit, yet still manages to be pear fresh and juniper-anise spicy.

There were just 2850 75cl vessels of Le Gin de Christian Drouin (95/100, $85) bottled in batch 2016-B and far fewer shipped to Australia. It's got a fabulous rounded texture and shows subtle juniper and ginger. It's delicious on the rocks.

Slightly larger in the still department are Angove's three copper pot stills, which were commissioned in 1911. At 6000, 7000 and 9000 litres, they could hardly be considered small batch, but they do lend a particular character to Angove's brandies. As winemaker Richard Angove told me recently: "It would be hard to replicate [Angove's style] in other stills. They've got steam coils rather than electric coils and the swan neck that comes out (of the still) goes up to the condenser, as opposed to down, which is unusual. We've been asked why, but all we can say is that's the way they've always been."

World class

Angove's top-tier spirits are bottled in tiny batches, as you'd expect of brandies with average ages of 20-year-old in Imperial XO (97/100, $295) and the 40-year-old Grand Reserve (97/100, $795). These brandies are world class, and about as complex as distillates from the grape can get.

Comparable to the mind-blowingly complex, rancio, candied-peel, old-vellum tasting 1991 Jean Grosperrin Collection Cognac Bois Ordinaires de L'Ile d'Oléron ($300) of which there are just a dozen or so 500ml bottles left in the country. The entire bottling of Lot No. 276 of this ethereal spirit was just 117 litres, or 234 bottles. Definitively small-batch.

As is the Willett Straight Rye Whiskey Rare Release from Kentucky (98/100, $220). I had something of a whiskey and Bourbon epiphany when visiting Tennessee last year: I finally got it that the finest American whiskeys had more in common with Armagnac than the malted barley products to north of Hadrian's Wall. Anyhow, the fudgy, raspberry, candied peel tasting, super-slinky and smooth Willett Rare Release is the finest spirit I've tasted north of Trump's Wall. Assessed within our borders at least.