FLORENCE (THE WASHINGTON POST) - There was a line to get into Florence's Galleria dell'Accademia, where clots of tourists peered up at Michelangelo's luminous David, his every line a rebuke to those of us neglecting our physical and spiritual fitness. There was a longer line to get inside the hulking Duomo, its glowing interior of saints gesturing toward centuries of struggle and grace. There were lines to the Uffizi Gallery and the Palazzo Vecchio, even for the tubs of gelato I wanted to plant my face in.

There were lines, in fact, for virtually every Florentine delight we wanted to visit when we were in Italy last year - save one. We walked right into Caffe Giacosa, formerly Caffe Casoni, reputed birthplace of the Negroni. The Negroni may not be the Sistine Chapel or Neapolitan pizza, but it is one of Italy's great gifts: a three-part harmony of gin, sweet vermouth and bitter Campari, typically served over ice with a slice of orange. My husband ordered the classic, while I swerved toward the white Negroni, and we spent the hour sipping our drinks and eating salty snacks that complemented them perfectly, watching the lines-to-be pass us by.

I will drink a Negroni any time of year, but I find bitter spirits particularly appealing in these sweltering months. On the tongue, bitterness can balance sweetness, cut through fat and add intrigue to salt (think of how bitter broccoli rabe finds its apex matched with sharp provolone). These are matters of the palate, but I find bitterness also slices through heat and humidity, a sharp slap to the system.

Much has been written on the history of the Negroni, the most credible story being one of an Italian count Negroni who, in 1919, asked the bartender at Caffe Casoni to boost his Americano (Campari, vermouth and soda) by subbing gin for the soda. In the years of the cocktail renaissance, the Negroni has spawned hundreds of variations.

These bitter apples sometimes fall far from the tree. Once I started encountering "negronis" with banana liqueur, muddled basil, lemon soda and so forth, I began to fear the nomenclature of the Negroni was drifting the way the martini did in the 1980s, when people started hanging a "tini" on the end of any drink served in the same kind of glass.

And as bartender and author Gary Regan argued in his 2015 book, The Negroni: "These fits of fancy often lead to interesting drinks (but, I'd argue, rarely better ones)."

I tend to concur. Last fall, when someone pitched me on a "pumpkin spice Negroni", a small part of me died.

Still, as Mr Nick Farrell, who often plays with bitter liqueurs (known in Italy as amari) in his role as spirits manager at Iron Gate Restaurant in Washington, points out, "you can't be super pedantic and draw bright lines and say, 'Well, this one is a Negroni and this one isn't', because it is a drinking culture and it all gets fuzzy after awhile".

Plus, many Negroni spin-offs are worth investigating - the "white" Negroni is one. Invented by bartender Wayne Collins in 2001, the recipe is an equal-part split of gin, the aperitif Lillet Blanc and Suze, a bitter gentian-based liqueur - and it too is now regularly spun into new drinks.

At Caffe Giacosa in Florence, I ordered the white Negroni because I wanted to taste its Suze substitute, a golden liqueur called Biancosarti, which is not available in the United States. Salers, the oldest of the gentian liqueurs, and Aveze are accessible here, and at Iron Gate, Mr Farrell likes to make a white Negroni with an American gentian, Breckenridge Bitter. His first white Negroni was made by the restaurant's former bartender Jeff Faile, who dropped the gentian liqueur in favor of gin, white vermouth and the bittersweet Cocchi Americano.

Despite their similar builds, the original and white Negronis are very different, primarily because the bitterness of gentian liqueurs is quite distinct from that of Campari. Due to brand secrecy around the specific botanicals, it is hard to be certain about components of these liqueurs, but although Campari likely contains some gentian - the plant that lends bitter bite to countless amari - liqueurs such as Salers and Suze highlight gentian's herbal and floral notes, while Campari leans towards the bitterness of citrus and spice. If you put a classic Negroni and a white one beneath the nose of a blindfolded bartender, she would be able to tell the difference based solely on their aromatics. When I am composing drinks and deciding the kind of bitterness I want, I tend to think of the red bitters as variations of Brooding Orange, the gentians as variations of Angry Lawn.

This has been complicated by Luxardo's new Bitter Bianco, which places gentian more subtly within a spectrum of other flavors: The Bitter Bianco is citrusy on the nose, like freshly cut orange peels, and has citrus and pear and an almost honeysuckle-like note in its bitterness. Mr Matteo Luxardo, a sixth-generation member of the family and export director for the company, told me they infuse the liqueur with some wormwood at the end of the process, giving it a lingering bitter finish. By design, it is closer in flavour to Luxardo's own red bitter than it is to the gentian liqueurs it visually resembles. It certainly provides a new means for exploring the Negroni format.

If you are a Negroni lover looking to create a variation that soars while staying loyal to the original template, Mr Farrell suggests getting to know what your components taste like, beyond simply knowing that amaro is bitter. You are looking for flavors that go together, "so knowing that Campari is more orange-forward or that Montenegro has that orange plus some vanilla... Once you have a better understanding of flavour affinities, you can make those matches" with base spirits and particular vermouths or aperitif wines. Find components that you like to drink on their own, or with a splash of club soda, and then think about what spices and flavours complement them. You may land somewhere far from the drink's Florentine roots, but very close to delizioso. And you will not have to fight any tourists to get into your liquor cabinet.

Recipes:

Negroni Bianco

1 serving

Luxardo Bianco is available at Ace Beverage and Batch 13, both in the District.

Adapted from a Luxardo-branded recipe.

Ingredients

Ice

1 ounce London dry gin

1 ounce blanc/bianco vermouth

1 ounce Luxardo Bitter Bianco liqueur (see headnote)

2 dashes celery bitters (optional)

Grapefruit peel or orange slice, for garnish

Steps

Place a large ice cube in a rocks glass and hold in the freezer while you make the drink.

Fill a mixing glass with ice. Add the gin, vermouth, liqueur and the bitters, if using, and stir for about 15 seconds, or until well chilled.

Strain into the chilled rocks glass. Express the grapefruit peel over the surface of the drink (by twisting it) and drop it in, or simply add the orange slice.

Nutrition | Per serving: 170 calories, 0 g protein, 6 g carbohydrates, 0 g fat, 0 g saturated fat, 0 mg cholesterol, 0 mg sodium, 0 g dietary fiber, 0 g sugar

Hierba Amarilla

1 serving

We found Suze (a gentian-based liqueur or bitters) and Cocchi Americano at Ace Beverage; Montgomery County liquor stores also carry them.

Ingredients

Ice

1¼ ounces mezcal

1 ounce Cocchi Americano aperitif wine (see headnote)

¾ ounce Suze liqueur (see headnote)

Lemon or orange peel, for garnish

Steps

Chill a Nick and Nora glass or cocktail (martini) glass.

Fill a mixing glass with ice, then add the mezcal, wine and liqueur. Stir for about 15 seconds, or until chilled.

Strain into the chilled glass. Express the citrus peel over the surface of the drink (by twisting it). Press it against the rim of the glass, then drop it into the drink.

Nutrition | Per serving: 130 calories, 0 g protein, 0 g carbohydrates, 0 g fat, 0 g saturated fat, 0 mg cholesterol, 0 mg sodium, 0 g dietary fiber, 0 g sugar