What is citric acid and how is it used?
Citric acid was discovered by Islamic alchemist Jabir Ibn Hayyan in the 8th Century, but it was first crystallised from lemon juice by the Swedish chemist Carl Wilhelm Scheele in 1784. It wasn’t until 1890, though, that citric acid was produced on an industrial scale.
Citric acid is primarily used as an ingredient in processed food and drinks. For example, the dairy industry uses citric acid in cheese production and processing. Beer and winemakers use it to adjust pH solutions during manufacture. Processed food producers add it to some fats and oils to enhance antioxidants, effectively reducing their deterioration. This versatile acid is also an industrial staple in the cosmetic and pharmaceutical industries.
Citric acid was first used in cocktails by way of industrially made ingredients like cordials. Until bartenders like Tony Conigliaro pioneered the molecular mixology trend, breaking down flavour profiles, including acid, in cocktails like Terroir, served at his bar with no name, 69 Colebrooke Row, in 2009. The Fluid Movement team also formed in 2009, they set up bars Pearl and in 2011, The Worship Street Whistling Shop. They used commercial acids in drinks, for example, to recreate the flavour profiles of non-alcoholic versions of their famous cocktails; “We ended up creating a botanical hydrosol that we altered at the other end using sugar, acid, salts and finally pine essence to give the impression of juniper.”— Matt Hastings, a head consultant for Fluid Movement said to Imbibe in 2018.
Ryan Chetiyawardana worked at 69 Colebrooke Row and The Worship Street Whistling Shop, honing his craft and growing a reputation for meticulous science, artistic flair and a thoughtful and theatrical hosting style. Then, in 2013, he and partner Iain Griffiths opened White Lyan, a bar championing closed-loop sustainable practices. It was the first bar in the world to remove perishables like fruit and ice from the entire operation. This meant that staple fruit in classic cocktails such as lemons and limes were supplanted by commercial acids. A practice that high-profile establishments around the world have since adopted.
Why is citric acid used in cocktails?
Citrus juices and peels have been used in the homes of wealthy citizens of ship-wielding empires as an ingredient in mixed drinks and kitchen recipes as a flavouring agent and cultural sign of prosperity for hundreds of years. Citrus was also introduced to alcohol as a health benefit. Limes provided essential vitamins to malnourished sailors and prevented diseases like scurvy. Then, during prohibition, boats of people were shipped to islands like Cuba on booze cruises, where limes were prevalent and served in cocktails like the Daiquiri. Later, citrus became entrenched in the cocktail culture of the Tiki period. And most recently, a flamed orange zest garnish was utilised to international effect by Dale DeGroff as a garnish for the Cosmopolitan cocktail. With bartenders citing this memorable serve and the man behind it as beginning the wave of hostility towards manufactured premixed citrus concentrate in favour of freshly squeezed juices, and the dawn of the modern-day cocktail revolution.
So citrus fruits are exotic, healthy and exciting to the senses, but it can’t be an accident that they are so particularly good at balancing cocktails and have appeared at every step of cocktail evolution. A cocktail should balance alcohol, sugar, acidity, and bitterness, so what happens chemically when citrus is added?
The pH scale measures the concentration of hydrogen and hydroxide ions which tells us how acidic or alkaline a liquid is. Acids are between 0 and 7, and alkaline between 7 and 14 on the pH scale. Acids are characteristically sour, while alkalies are bitter. Different alcoholic bases have different pH levels, and the addition of citric acid can heighten the sour flavours. Sourness is then counterbalanced by sugar. Citrus fruits have inherent sweetness too, and therefore can provide two elements of balance to the cocktail, reducing the need for additional ingredients. However, the acidity of the alcoholic ingredients are variable, the amount of sugar per fruit is variable, and the amount of citric acid and oxidation over time is also variable. So it takes a skilled palette to create new recipes, and it’s almost impossible to recreate an exact recipe with these variations in play.
So citric acid allows bartenders hyper-control over the pH of their cocktail. It informs the balance of ingredients in a scaleable way so that whether you’re making five or 500, you can keep the balance of your drink consistent.
Citrus Science vs Nature
Citric acid is available as an odourless and colourless compound. Until the early 1900s, it was produced directly from lemon juice, but now it’s made from Aspergillus Niger, a mould that produces citric acid as a by-product when it feeds on sugar.
This may turn the stomach and even put customers off a menu description, but the dichotomy of the natural versus the artificial breaks down once you realise that the compound is as natural as blue cheese or sourdough bread. The argument is really about romance. The romance of citrus is still alive and well in our culture. Some customers and bartenders will happily eschew the logic of scientific reasoning if it means maintaining the cultural significance of citrus fruits. The smell, the look, the taste, the method, the history of a cocktail and the evocation of the origin of the fruit (Amalfi lemons or Key limes, for example) all inform the service choices made.
Experimenting with Citric Acid in Cocktails
Essentially, citric acid can make food fresher for longer, reduce food waste, and closely control a cocktails’ pH balance. All you need is a bit of forethought, a sound palette and an experimental mindset to start trying it out in recipes. There are also other types of acid, and each one can be used differently to affect the overall balance of your drink.
You could try using verjus, shrubs, commercial powders or soluble liquids, kefir or starter cultures. Try matching acids to flavours, using them to prolong the life of batched drinks, save you prep time and food waste, turn solids into liquid ingredients or to wrangle your purchasing power away from large international, air-mile guzzling distributers and towards small, local growers. To get you started, this video by the Bacardi team Ambassadors gives you an overview of the different types of acids, where they are found and what they might add to a drink.