Tom Collins Cocktail Recipe 5 mins 2 drinks Gin Ingredients 90ml Gin 60ml Lemon Juice 30ml Gomme Syrup Soda Water Get all your USA cocktail ingredients at ReserveBar Affiliate link — we may earn a commission at no extra cost to you. Directions Combine the Gin, lemon juice and gomme syrup in a shaker with ice. Shake for 20 seconds. Pour between two tall glasses, over ice. Top with soda water and garnish with a slice of lemon.