How to make a flavoured syrup

A flavoured syrup is a bar syrup with a flavour drop stirred through it once it is cool. Bartenders keep two, and name them in Brix, the grams of sugar in every 100 g of syrup: simple syrup is 50 Brix, equal weights of sugar and water, and rich syrup is 66.7 Brix, twice the sugar to the water. Neither needs a boil or a thermometer, and both take a teaspoon of flavour to a 400 ml batch.

• Makes about 400 ml, which fills a $2 sauce bottle from Kmart, and scales to any bottle with the calculator
• Takes about 5 minutes, plus cooling time for rich syrup
• You need a kitchen scale, a jar with a lid or a jug, measuring spoons, a clean bottle

What you need

• For simple syrup: 245 g white sugar and 240 ml water
• For rich syrup: 355 g white sugar and 170 ml warm water
• A bottle of Jerk Soda Flavour Drops: 5 ml, a teaspoon, for either batch, whichever flavour it is
• Optional: citric acid, malic acid, or fresh lemon juice, for a syrup that wants its own brightness rather than borrowing it from the glass

How to make it

1. Weigh the sugar and the water into a jar or a jug. For rich syrup, use water warm from the tap or the kettle, well short of boiling.
2. Seal the jar and shake it, or stir, until the syrup runs clear with no grit left at the bottom. Simple syrup dissolves cold in a few minutes. Rich syrup needs the warm water to get all of its sugar in.
3. Let it come fully to room temperature.
4. Stir in the acid first if you are using one, then the 5 ml of flavour. The water above is already 5 ml short to make room for it: the flavour takes the place of that part of the water.
5. Bottle it into something clean, ideally run through a hot dishwasher cycle, and refrigerate it.

Why it works

The two syrups are the sweetness control. Both carry the same flavour in a batch, so the pour that puts the flavour where you want it is about the same, and what changes is the sugar that comes with it. About 7 ml of either flavours a 250 ml glass: from simple syrup that brings about 4 g of sugar, and from rich about 6 g, along with more body. Pick the syrup for how sweet the drink should be, and let the pour look after the flavour.

Brix is a measure by weight, and that is why this page weighs rather than fills cups. Half sugar by weight is 50 Brix every time; half sugar by volume is something else, and it changes with how the cup was scooped.

A syrup flavoured by a concentrate, the way these are, holds its flavour at either strength, so rich syrup costs nothing in flavour and keeps longer. A syrup flavoured by fruit juice is usually kept to 1:1 instead, because at 2:1 the sugar outweighs the fruit.

Neither needs a boil because neither holds more sugar than water can take up. Simple syrup is well inside that at room temperature. Rich syrup sits right at the edge of it, which is why it wants warm water: cold, the last of the sugar stays at the bottom of the jar.

Flavour goes in once the syrup is cool for a reason you can taste. The brightest and most identifying part of a flavour is also the most volatile, so a concentrate stirred into warm syrup loses its top note into the kitchen and leaves the flatter half behind in the bottle.

Where a flavour offers an acid, it earns its place twice. It cuts the sweetness, so a fruit syrup reads as fruit rather than as sugar with a smell behind it, and it takes the pH down a step, which leaves the bottle a little less hospitable to whatever might otherwise grow in it. Read that second part as a help alongside refrigeration rather than a replacement for it.

Make it yours

• Simple syrup for a tall, cold drink that wants flavour more than sugar. Rich syrup where you want body and sweetness, and for a bottle that has to last.
• Lighter or stronger: pour about a third less or a third more, rather than changing the flavour in the batch.
• A short coffee is better with drops straight into the cup, where no sugar comes along with the flavour.
• Leave any optional acid out entirely on a base that already brings its own citrus, a lemonade or an L&P, and add it only where the glass has none.
• To fill a particular bottle, multiply its size in millilitres by 1.23 for simple syrup or 1.33 for rich, and weigh out that many grams in total: half of it sugar for simple, two thirds for rich. Syrup is heavier than water, so splitting the millilitres straight into sugar and water comes out short of the bottle.
• For a fruit syrup, use juice in place of the water and keep it at 1:1. Juice brings some sugar of its own, so it lands a little above 50 Brix.
• The syrup calculator scales either syrup to any bottle, and gives the pour.

Notes

The pours above give a glass the same flavour as drops at the standard rate, so a syrup build and a drop build taste alike. For a 330 ml can it is about 9 ml of either. How to use the drops has the rate.

A refractometer checks a batch in a few seconds: a drop on the prism reads its Brix. It has to read past 70 Brix to be any use here; the kind made for fruit and wine often stops around 32. The flavour and any acid barely move the reading.

Citric acid runs about 0.1 to 0.3 per cent of the batch, and malic acid, which reads rounder and less sharp, runs about 0.2 to 0.5 per cent. Citric acid sits in the baking aisle at any supermarket here. Malic acid does not: a bulk-food shop or a homebrew supplier is where it turns up, so order it ahead, or use fresh lemon juice in place of either.

A syrup finished with dairy, such as milk powder or condensed milk stirred through a caramel syrup, keeps only 3 to 5 days refrigerated, however long the plain syrup would have lasted.

Rich syrup keeps longer than simple. We work to about 4 weeks refrigerated for rich and 2 for simple, house ceilings rather than food safety claims, because how long a syrup lasts depends on your fridge, how clean the bottle was and how often it comes out. Tip it out early if it turns cloudy, smells sharp or boozy, or grows anything visible. For longer, freeze it: in a plastic bottle, or in glass with the lid left off until it has frozen.

Allergens and warnings. A plain syrup carries none from this method. Citric and malic acid carry no allergen either. The bottle lists what is in the concentrate, and the bottle is the authority on that rather than this page.