Book: All Day Cocktails
Several Citrus Waste Reduction Processes from Laura Newman of Queens Park Birmingham

Using Leftover Citrus to Make Flavored Syrups and Caramelized Citrus Wheels

4HatTruckerAt Liquor Lab in New York, Nate Fishman says that they often need to find ways to use up citrus. As a "social mixology experience" they don't have the daily hours of operations that traditional bars do, so there are times when citrus juice/fruit won't get used before it goes off.

To make use of citrus fruit that won't be juiced, first they make dehydrated citrus wheels. Then if they still have more citrus than they can use, they do a combination technique to make both flavored syrups and caramelized citrus wheels. 

Fishman writes, "We take the leftover citrus wheels and macerate them with different sugars, similar to an Oleo Saccharum but we use the citrus meat as well as the rind. We match our citrus with these sugars based on their flavor profile."

Orange with Muscovado - We pair the Muscovado with orange due to its strong molasses content.
Grapefruit with Demerara - As the grapefruit is used in lighter cocktails we use a lighter sugar in Demerara.
Lemon & Lime with Granulated Sugar - Lemon and lime are our most used citrus and we pair them with granulated sugar due to its light profile and ability to take on the citrus flavor without adding the molasses flavor of unrefined sugar.

 

All of the macerations can be made using the following.
Instructions:
Fill a container (usually 8 quart but any size will do) with leftover citrus wheels.
Cover with sugar.
Seal and let sit at room temperature for at least two days.
Stir occasionally.
The mixture will start to liquify gradually.
Once all the sugar has dissolved strain out the leftover citrus wheels.
Date the syrup and store in the refrigerator up to two weeks.

 

To make caramelized citrus wheel garnishes:

Use the sugar/syrup-dipped citrus wheels form above. 
Put them in the oven at 175F/80C for about 24 hours. 

 

Below is a cocktail that uses both the flavored syrup and the caramelized citrus wheel garnish. 

Añejo Old Fashioned
2 oz Santera Añejo Tequila
1/4 oz Orange Demerara Syrup
2 dashes Angostura Bitters

Stir / Rocks / Dehydrated caramelized orange wheel garnish