Quill At Quill, Sophie Szych's earthy, not-too-sweet gin rickey is made with a toasted coconut soda and a fermented lime/ginger/basil syrup. (Fritz Hahn/The Washington Post)

As temperatures climb and humidity gets heavier, my thoughts invariably turn to the rickey. Invented at a Washington bar called Shoomaker's Resort in the 1880s, and named for lobbyist Col. Joe Rickey, no other cocktail cuts through summer temperatures as well as this basic mix of gin or bourbon, soda water and the juice of half a lime. Rickey preferred his cocktails with bourbon, though gin has become the more popular ingredient. Both versions are incredibly refreshing; as cocktail historian David Wondrich once noted, the rickey is "air conditioning in a glass."

Since 2008, the D.C. Craft Bartenders Guild has declared July "Rickey Month," hosting an area-wide competition that encourages bartenders to come up with their own riff on the recipe. To keep things equal, all cocktails must include Half Moon gin, Knob Creek bourbon or Knob Creek rye, lime juice and either sparkling water or soda over ice. After that, all ingredients, infusions and variations are left to each mixologist's imagination. Last year's winner, Julien Bourgon of Bar TNT, mixed bourbon with a homemade cantaloupe soda and "ice cubes" created by putting honeydew melons in liquid nitrogen.

Fifty-two bartenders are participating in this year's Rickey Month – the most yet. Some bar staffs get extra competitive: Bourbon Steak, Graffiato, Hank's on the Hill and Sixth Engine have each entered three bartenders, all of whom have created their own drink. Cocktails must be featured on bar menus throughout July.

The area's champion rickey will be crowned during an Aug. 3 party at Jack Rose, which is open to the public. The $35 ticket includes unlimited samples of six-to-10 different rickeys and passed hors d'oeuvres. In a new twist this year, the D.C. Craft Bartenders Guild is collecting all 52 recipes into a book, which will be for sale at Jack Rose.

Of note: A panel of judges (including yours truly) tasted all 50 rickeys last summer to create a shortlist of our eight favorites. Four of the bartenders on that list are returning to the competition this year: Dane Nakamura of Range, Rachel Sergi of Lincoln, Lukas Smith of Daikaya and Jess Woods of Room 11.

The full list of participants, organized by bar:

Danielle Paulson - A&D Neighborhood Bar
Chris Martino - Barrel
Donnavon Lalputan - Beuchert’s Saloon
Engidawork Alebachew - Bourbon steak
Sean Steel - Bourbon Steak
Lauren Wingender - Bourbon Steak
Damian Torguson - Brabo
Noah Broaddus - Cafe Saint-Ex
Ben Wiley - Cafe Saint-Ex
Dustin Beruta - Cashion's Eat Place
George Manolatos - Cashion's Eat Place
Lukas B. Smith - Daikaya
Philip Tickner - District Commons
Phil Heyser - Elizabeth's Gone Raw
Matt McGrady - Farmers Fishers Bakers
Danielle Revers - Farmers Fishers Bakers
Aaron Del Giudice - Firefly
Santchai Crawford - Founding Farmers (Potomac)
Ben Matz - GCDC
Frank Jones - The Gibson
Adam Jarvis - Graffiato
Taha Ismail - Graffiato
Rico Wisner - Graffiato
Eve Maier - Hank’s Oyster Bar (Dupont Circle)
Burke Podany - Hank's Oyster Bar (Dupont Circle)
Clare C. Duncan - Hanks on the Hill
Sam Schmidt - Hanks on the Hill
Mike Saccone - Hanks on the Hill
Justin Hampton - Jack Rose Dining Saloon
Arleigh Incarvite - Jack Rose Dining Saloon
Megan Wilson - Jack Rose Dining Saloon
Scotty Holland - Kapnos
Rachel Sergi - Lincoln
Galen Odell-Smedley - Mockingbird Hill
Jason Wiles - Notti Bianche
Steve Bunch - Old Ebbitt Grill
Andrius Miliunas - PX
Sophie Szych - Quill (at the Jefferson Hotel)
Dane Nakamura - Range
Bryan Tetorakis - Rogue 24
Jess Woods - Room 11
Nate Mann - Room 11
Brian Nixon - Rose's Luxury
Donato Alvarez - Sixth Engine
Jo-Jo Valenzuela - Sixth Engine
Casey Hristakos - Sixth Engine
Jen Semo - The Source
Eric Hodge - Southern Efficiency
Christine Kim - Tico
Aaron Fernando - Tryst
Horus Alvarez - Vinoteca
Aaron Joseph - Wit and Wisdom Tavern