How to make cocktails

Sugar and sugar syrup

Words by Simon Difford

Many cocktails benefit from sweetening but granulated sugar does not dissolve easily in cold liquids, particularly alcohol. Hence pre-dissolved sugar syrup (also known as 'simple syrup') is used. 'Gomme sirop' or 'gum syrup' is sugar syrup with the addition of gum arabic, the crystallised sap of the acacia tree, which adds mouth-feel and smoothness to some drinks.

Along with ethanol alcohol sugar is the most used ingredient in all cocktails. Sugar syrup is one of the simplest and yet also most misunderstood and complex products used by bartenders. Follows an explanation of the different types of sugar, strengths of sugar syrup, and how to make sugar syrup. With so many bars listing 'skinny' cocktails, we also explore different types of non-sugar 'sugar syrups' made using artificial sweeteners.

Degrees of sweetness (brix)

The balance between sweet and sour is crucial to the majority of cocktails and consistently producing balanced cocktails is made easier when using sugar syrup with a known and constant sweetness.

The degree of a liquid's sweetness is measured on a scale called 'brix'. At 20°C, 1.0°brix is equal to 1 gram of sugar in 100 grams of water and sugar solution. Or, to put it another way, there is 1 gram of sucrose sugar and 99 grams of water in the 100 grams of solution.

Sugar syrups tend to be made according to two recipes: 'one part sugar to one part water' (1:1) and two parts sugar to one part water (2:1). The former, 1:1, is the most common type of syrup used in American bars and can be made by simply shaking sugar and room temperature water together in a sealed container so is appropriately known as 'simple syrup'.

In British and other European bars 2:1 sugar syrup, known as "rich sugar syrup" is more common and this is the sugar syrup used in all Difford's Guide recipes. 2:1 sugar syrup (by volume - see below) is also around the same degree of sweetness found in most commercially produced sugar syrups and it is common for European bars to buy in bottled syrup rather than make their own to help ensure consistency. The willingness to buy rather than make is also driven by the fact that making 2:1 syrup involves the faff of gently heating and stirring the water and sugar.

I consider 2:1 syrup superior to 1:1 syrup as the use of 1:1 sugar syrup adds additional, perhaps unwanted, dilution to a drink compared to 2:1 syrup, typically around 5 to 8% depending on the recipe. It's a small percentage but worth eliminating. If desirable in a particular drink, dilution can be controllably increased by the addition of a measured amount of chilled water. If you worry about over dilution from bad "wet" ice then you should also care about the amount of water in your sugar syrup.

When making sugar syrup some people measure by weight (e.g. 2kg of sugar to 1kg of water) and other people measure by volume (e.g. 2 cups sugar to 1 cup water). Whether following a 1:1 or 2:1 ratio, measuring by weight results in a sweeter syrup than that made by measuring by volume.

A 2:1 (sucrose) sugar syrup made by measuring by volume has a 65.1°brix, a near-as-damn-it identical brix to the leading brand of commercially made cane sugar syrup. The following shows the differing levels of sweetness between the most commonly used (sucrose) sugar syrups.

Homemade sugar syrup 2 sugar to 1 water by weight = 66.7°brix
Homemade sugar syrup 2 sugar to 1 water by volume = 65.1°brix
Monin Pure Cane sugar syrup (855g sugar per litre) = 65.0°brix
Monin Gomme sugar syrup (835g sugar per litre) = 64.7°brix
Homemade sugar syrup 1 sugar to 1 water by weight = 50.0°brix
Homemade sugar syrup 1 sugar to 1 water by volume = 48.0°brix

To balance citrus fruits such as lemon and lime juice, a rough rule of thumb is to use 15ml/0.5oz of 65.0°brix (2:1) syrup to 30ml/1oz of citrus juice. If using a 48°brix (1:1) syrup you will need roughly 1.5 times as much syrup.

Different types of sugar

Bog standard cane sugar, the type we use in our tea and coffee is sucrose. When this is heated with water it breaks down into fructose and glucose through a process called hydrolysis to produce what's known as inverted sugar. Bakers prefer inverted sugar as products made using it tend to retain more moisture and are less prone to crystallization. But what is good in the kitchen is not good behind the bar.

Sucrose-based sugar syrup is the most viscous but if overheated during the syrup-making process then some of this viscosity will be lost as the sucrose hydrolyses into less viscous fructose and glucose. Fructose is the least viscous sugar with glucose slightly more viscous than fructose, but sucrose is almost twice as viscous as glucose.

While hydrolysing sucrose into fructose and glucose results in less viscosity it has the opposite effect on sweetness with a 50/50 sucrose and glucose syrup being around 25% sweeter than 100% sucrose syrup. (Glucose is about 75% of the sweetness of sucrose but Fructose is nearly twice as sweet as sucrose.)

How to make sugar syrup

Buy a proprietary brand of sugar syrup or make your own sugar syrup. We recommend making a 2 parts sugar to 1 part water (2:1) syrup as follows. White caster sugar is most commonly used but also consider using a dark sugar to make a syrup for use in cocktails based on dark spirits such as an Old-Fashioned.

1. Pour one cup of filtered or mineral water into a clean saucepan.

2. Add one cup (the same size as used for water) of caster sugar (dissolves easier than granulated) and stir using a clean stainless-steel spoon (not a wooden spoon).

3. Place on low heat and continue to stir briskly until all the sugar has dissolved.

4. Gradually add a second cup of sugar into the saucepan stirring as the sugar is added.

5. Heating helps the sugar to dissolve in the water but also has the negative effect of changing the sugar's physical properties. The more heat that is applied, the more the sucrose will break down to the less viscous but sweeter glucose and fructose. So do not let the water even come close to boiling and only gently heat for as long as it takes to dissolve the sugar. (The temperature should be low enough to be able to touch the sides of the pan.)

6. Allow syrup to cool and pour into a sterile empty bottle. Ideally, you should finely strain your syrup into the bottle to remove any undissolved crystals which could otherwise encourage crystallisation.

7. If kept in a refrigerator this mixture will keep for six months.

After making your syrup you'll notice that 1 cup water and 2 cups of sugar don't produce 3 cups of sugar syrup. Surprisingly the result is around 1.5 cups of syrup. The reason for this is that the sugar dissolves into the water, occupying spaces between the water molecules.

Gomme or gum syrup

When made with cane sugar (not beet sugar) this syrup is the king of sugar syrups, delivering the sweetness of 2:1 sugar syrup but with extra viscosity provided by the addition of gum Arabic - so much extra viscosity that it can add a discernible smoothness to cocktails as diverse as the Daiquiri to the Old-Fashioned.

Most of the companies commercially making this syrup are French so it tends to be called gomme sirop but is simply gum syrup in English. Like most bartenders, I tend to mix the French and English names to gomme syrup.

Gomme syrup was widely in use in the mid-1800s and E. Ricket and C. Thomas' 1871 Gentleman's Table Guide includes the following recipe:
"Dissolve 1 lb. of the best white gum Arabic in 1½ pints of water, nearly boiling; 3ilbs. Of white sugar or candy; melt and clarify it with half pint of cold water; add the gum solution and boil altogether for two minutes. This gum is for cocktails."

Gum arabic, the essential ingredient to this wonderful syrup, is also known as gum acacia or meska. This fine white power is made from the hardened sap of two species of the acacia tree; Senegalia (Acacia) senegal and Vachellia (Acacia) seyal. Gum Arabic is used in the food industry as a stabilizer and has the E number E414. It is also used in cosmetics, inks and the textile industry and is the glue used on postage stamps. Artists will be familiar with gum arabic as it is used as a binder for watercolours.

How to make gum syrup

When you come to make gum syrup for the first time you realise why its use has declined. While it takes only a few minutes to make 2:1 sugar syrup just teasing the gum arabic powder into a paste and then a solution takes at least ten minutes. Then you add your sugar and clarify. It's a bit of a faff but worth the effort.

1. Start by measuring one cup of filtered or mineral water and ¼ cup of gum arabic powder.

2. Like cornflour or cornstarch, gum arabic forms clumps when it comes into contact with water and is best first mixed with water at room temperature rather than hot water. Tip the gum arabic into a mixing bowl and add a small amount of the water from the mug. Using the back of a spoon mix the gum arabic and water first into a paste, gradually adding the rest of the water, and then into a straw yellow thick solution with a foamy head. This process takes 5 to 10 minutes but feels like an eternity so put the radio or music on before you start.

3. Pour your gum arabic and water solution in a saucepan over very low heat and add one cup of caster (not granulated) sugar. Stir the sugar into the solution until all the sugar has dissolved.

4. Gradually add a second cup of caster sugar into the saucepan stirring as the sugar is added.

5. Heating helps the sugar to dissolve in the water but also has the negative effect of changing the sugar's physical properties. So do not let the water even come close to boiling and only gently heat for as long as it takes to dissolve the sugar. (The temperature should be low enough to be able to touch the sides of the pan.)

6. Cover and allow syrup to cool. You will end up with a thick straw yellow syrup with a white foamy head. It helps if you cover and leave this to stand for at least 24 hours.

7. Pouring through a fine strainer into a sterile container with a tap near its base and leave for 24 hours to settle and so clarify. Draw of your gomme syrup through the tap to separate from any settled deposits and foamy head.

8. Place in a sealed sterile bottle and refrigerate where the gomme syrup will keep for six months.

Alternative non-sugar sweeteners

You can make syrups as described above using a sweetener in place of sugar. I tested several sweeteners and consequently I recommend XyloBrit.

XyloBrit (Xylitol)

1 spoon = 1 spoon of sugar. Dissolves like sugar and needs heat to make a 2:1 syrup. Produces a crystal clear liquid that does not foam when shaken.
Comment: Good flavour, close to that of sugar with a slightly thinner mouthfeel. Best finish of all three sweeteners I tried but not as good as sugar.
Difford's Guide rating: 4/5

Green Canderel (Stevia)

1 spoon = 1 spoon of sugar. Fizzes as it dissolves in water but dissolves easily without the need to heat.
Produces a clear liqueur with thin viscosity that foams when shaken.
Comment: Not quite sweet enough. Worryingly fizzy after shaking. Unpleasant finish. 2/5

Silver Spoon Truvia (Stevia)

1/3 spoon = 1 spoon of sugar. Harder to dissolve in water than Green Canderel and seems to benefit from being warmed. Produces a clear liquid with a slight straw yellow hue that looks like sugar syrup. Foams when shaken.
Comment: Structure of cocktail made using this syrup seems to break apart very quickly with thin foam on top of a cocktail. Good taste but with a disappointing finish.
Difford's Guide rating: 3/5

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