Gin & Tonic is the perfect summer cocktail. I like mine with plenty of ice, a good squeeze of lemon, and please, only homemade tonic syrup will do.
I’m not always such a snob (or maybe I am?) but now that I’ve made my own tonic syrup, good old Schweppes Indian Tonic Water just doesn’t rate. Schweppes served me well for years and years, but my newly sophisticated tastebuds find it overly sweet and one-dimensional, and its faint bluish tinge creeps me out (even though this is legitimate since quinine is highly sensitive to ultraviolet light). In contrast, homemade tonic syrup is soft and nuanced and coloured a deep rusty-orange. It’s delicious enough to drink on its own with soda, but when mixed with gin the complex botanicals intensify in flavour. In one sip you will taste lavender and lime, and in another, grapefruit and lemongrass. There is no return from this.
I first stumbled across the notion of homemade tonic syrup while reading the wonderful blog Lottie & Doof a few years ago. In a somewhat self-conscious post, Tim admitted that brewing his own tonic took him to a whole new level of kitchen geekiness. Fortunately, I have a soft spot for geeks, being one myself, and Gin & Tonic is my all time favourite cocktail. Tim’s post was dutifully bookmarked…then time went by and I forgot all about the recipe.
A few months ago I was at a market and spotted a stand selling bottles of small-batch tonic syrup. I bought some and it was as delicious as they promised – wonderfully soft and fragrant, with less sweetness than commercial tonic. However, it tasted very strongly of lime. I felt like I was drinking Lemon, Lime & Bitters not Gin & Tonic, and remembering Tim’s post, I resolved to finally try my hand at the recipe. Time’s have changed since Tim wrote about homemade tonic. Bars don’t employ bartenders anymore; it’s all about mixology and making your own syrups and bitters to use in unique, customised cocktails. Tim didn’t realise how cool he was back in 2012.
To make your own tonic syrup you first need to track down a supply of cinchona bark, which contains quinine and gives tonic its characteristically bitter flavour. It’s not easy to get hold of, but I ordered mine online from this Australian company which ships internationally. Once you have it, it’s a fairly simple matter of combining a range of botanicals with water, simmering it briefly, then leaving it to infuse for a couple of days before straining, letting it sit for another two days and finally mixing it with sugar syrup. OK, ok, so it will take you days to make this (four, to be exact), but I promise that it’s worth it. The recipe given below makes a large amount which is plenty for drinks all summer long and equally wonderful gifted in small bottles to friends.
The recipe below is my tweaked version of the original. I found my first batch to be a little sweet and the lavender a touch too dominant. In subsequent batches I have experimented with reducing the sugar and moderating the lavender with other spices, such as coriander seeds. The beauty of making your own tonic is that you can adjust it as you like. For my next batch, I plan on trialling a more wintery version, replacing the lime with orange zest and using coriander seeds, cinnamon sticks and black peppercorns in place of the lavender. A word of caution: quinine can be toxic in high doses so it is advisable to do your homework, treat the cinchona bark with respect and measure it carefully. The risk is heightened if the syrup isn’t strained properly and fine bits of bark remain in the liquid. To mitigate this, I use the whole bark (rather than buying a pre-milled powder) and take care to strain it thoroughly – full instructions are given in the recipe below.
Homemade Tonic Syrup
For the infusion:
4 cups water
1/4 cup cinchona bark (see below for instructions for grinding)
1/4 cup citric acid
3 limes, zest only
3 lemons, zest only
1 grapefruit, zest only
1 cup chopped lemongrass (3-4 stalks)
9 whole allspice berries, lightly crushed
6 whole cardamom pods, lightly crushed
1/4 tsp salt
1/2 to 1 Tbsp lavender (optional, or substitute 1 Tbsp coriander seeds)
For the simple syrup:
2-3 cups sugar
1-1.5 cups boiling water
To grind the cinchona, blitz it in a spice grinder just until it is broken into small pieces. Following this, sieve the bark to remove any fine particles before measuring out 1/4 cup and adding it to the pot.
Place all other ingredients for the infusion into a medium saucepan, cover with a lid and bring to the boil over medium-high heat. Reduce the heat to low and simmer for 30 minutes. Take the pan off the heat and leave to cool completely.
Once the infusion is cool, transfer the liquid and all of the solids to a large jar or jug. Cover and stash in the fridge to macerate for two days. Strain the liquid through several layers of fine cheesecloth set over a bowl to remove the solids. A little gentle squeezing is fine to help release the fluid from the solids. Pour the strained liquid back into the jar or carafe and place it back in the fridge for another two days. During this time a fine sediment may settle at the bottom. After two days, pour off the liquid at the top into a clean vessel, ensuring that none of the sediment escapes. If you wish, you can strain the liquid again through coffee filters, but provided that you didn’t grind the bark too finely to begin with, you shouldn’t need this extra step.
Measure the infusion so that you know how much rich simple syrup you need to make. You should have around 2.5 to 3 cups of infusion. Both Tim and Tony advise adding an equal amount of rich simple syrup, but I find this too sweet for my taste. The last time I made it I had 2.75 cups of liquid and I combined this with 2.25 cups of rich simple syrup and the sweetness was just right for me. It doesn’t hurt to try the smaller amount of simple syrup as you can always add more later.
Making the simple syrup takes a little guess work. The ratio is two parts sugar to one part boiling water, stirred to dissolve the sugar, but the actual quantities you need will depend on how much infusion you end up with. Start with the smaller amounts of sugar and water provided in the ingredient list above and make more simple syrup if you need it. This is less tedious than you might think.
Store your tonic syrup in the fridge where it should keep well for at least six weeks, if not more. To make a Gin & Tonic, measure equal quantities of gin and tonic syrup into a glass filled with ice. Add a squeeze of lemon and top up with soda water or sparkling mineral water. Taste the drink and adjust the proportions if required.