The first thing customers notice about a drink is its fizz. A lively sparkle, a crisp mouthfeel, and a bright aroma all depend on how well a drink holds its carbonation. When the fizz is weak, the entire experience falls flat. Drinks taste dull. Foam collapses early. Presentation suffers. For venues that rely on consistent dispense (bars, breweries, restaurants, and fast-food chains) poor fizz becomes a direct threat to customer satisfaction and repeat sales.
Carbonation is more than bubbles. It shapes flavour, aroma, and texture. CO₂ lifts the drink on the palate and delivers the refreshing snap people expect. When CO₂ levels drop, the drink loses its energy and becomes far less appealing.
Most carbonation issues start with CO₂ quality, not the drink itself. Contaminated gas, incorrect pressure settings, warm storage temperatures, or the wrong gas blend all affect how CO₂ dissolves and stays in the beverage. Even minor changes in gas purity or pressure can make drinks appear flat long before the keg or syrup bag is empty.
In this guide, you’ll learn how CO₂ works inside a drink, why fizz is so sensitive to gas quality, and the practical steps you can take to improve carbonation levels in your draught systems. The goal is simple. Better fizz, better flavour, and more consistent drinks across every pour.
What Controls CO₂ Levels in Drinks?
A great drink should feel bright, lively, and refreshing from the first sip to the last. The fizz should lift the flavour, support the aroma, and create a clean, satisfying mouthfeel. When carbonation is right, drinks taste sharper, smell fresher, and look more appealing. Customers notice this instantly, and they return for it.
When fizz fades early, it signals a deeper issue in the drink’s gas supply or dispense system. CO₂ levels don’t drop by chance. They change because one or more factors disrupt how the gas dissolves or stays in solution. Understanding these factors is the first step towards fixing flat drinks and preventing repeat issues.
Carbonation and CO₂ Absorption
CO₂ dissolves into drinks under pressure. This process follows a simple principle known as Henry’s Law: the higher the pressure, the more CO₂ the liquid absorbs. When pressure is stable, carbonation remains consistent. When pressure fluctuates, CO₂ escapes, and drinks lose their sparkle.
In draught systems, correct pressure settings push CO₂ into the beverage and hold it there until the moment of serve. If pressure drops too low, the drink can’t retain gas. If it rises too high, the drink becomes harsh or foamy. Maintaining the right balance keeps carbonation tight and predictable.
The Impact of Temperature
Temperature is equally important. Cold drinks absorb and hold CO₂ much more effectively than warm drinks. If the keg room, syrup room, or cellar runs too warm, CO₂ escapes quickly, leaving drinks flat and lifeless.
Even small changes matter. A few degrees of warmth can reduce carbonation levels noticeably. This is why consistent cooling and proper storage are essential for stable fizz across every serve.
Gas Quality as a Hidden Variable
Many operators assume flat drinks are caused by pressure issues alone. In reality, CO₂ purity plays a major role. Drinks lose fizz quickly when the gas contains impurities that break down carbonation or interfere with how CO₂ interacts with the liquid.
Common problems include:
- Contaminated CO₂ from poorly maintained supply chains
- Low-grade cylinders that introduce moisture or oil
- Hydrocarbon and sulphur impurities that weaken carbonation and distort flavour
Low-quality CO₂ cannot hold carbonation as effectively as clean, polished gas. Impurities disrupt the drink’s natural balance, causing fizz to fade faster and altering the sensory experience. This is why venues using contaminated gas often notice repeated flat pours, even when pressure and temperature appear correct.
Gas purity is the variable many teams overlook – but once controlled, it transforms consistency and drink quality.
Common Reasons Drinks Lose “Fizz”
Flat drinks rarely come from the beverage itself. They come from the conditions around it: the pressure, the purity of the gas, the blend in use, and the hygiene of the system. When one of these elements slips, carbonation suffers. Here are the most common causes.
Inconsistent Pressure
Pressure is the driving force behind carbonation. When pressure is too low, drinks pour flat and taste lifeless. The mouthfeel becomes soft, the aroma loses its lift, and the drink settles in the glass without any sparkle.
When pressure is too high, the opposite happens. Drinks erupt with foam, taste sharp, and feel harsh on the palate. High pressure also affects head retention in beer and can ruin the pour.
Symptoms of pressure problems include:
- Slow, flat pours
- Sudden bursts of foam
- Large, unstable bubbles
- Carbonation that fades within minutes
Even small pressure changes have a big impact on CO₂ absorption and retention.
CO₂ Contamination
Poor fizz often points to dirty CO₂. Even when labelled “beverage-grade”, CO₂ can still contain trace impurities that weaken carbonation and distort flavour. These include:
- Hydrogen sulphide (sulphurous smell)
- Hydrocarbons (plastic, oily, or chemical notes)
- Moisture (dilutes carbonation and disrupts pressure stability)
These contaminants interfere with how CO₂ dissolves and stays in the drink. They make it harder for the beverage to hold gas, so fizz disappears faster than expected. This is why two identical drinks (same recipe, same keg, same temperature) can behave differently when one system has contaminated CO₂.
Many venues only discover this problem after installing a CO₂ polishing filter and seeing instant improvements in fizz, flavour, and foam stability.
Gas Blend Issues
Different drinks require different gas blends. When blends are wrong, carbonation is the first thing to suffer.
For beer:
- Lagers and high-carbonation beers need 100% CO₂.
- Stouts and some ales need mixed gas, usually 25–30% CO₂ with 70–75% nitrogen.
If these ratios slip, beer can taste flat, pour with excess foam, or lose its expected mouthfeel.
For fountain drinks:
Unbalanced carbonator settings cause inconsistent fizz. If water, syrup, and CO₂ aren’t in the right proportions, drinks pour weak or overly sharp. Incorrect blends are one of the fastest ways to damage carbonation. Eeven when temperatures and line hygiene are perfect.
Poor System Hygiene
System hygiene affects carbonation far more than most operators realise. Moisture, residue, and syrup build-up create conditions where CO₂ cannot dissolve or hold properly.
Poor hygiene leads to:
- CO₂ absorption issues
- Pressure instability
- Off-flavours
- Inconsistent fizz across different taps
Gas lines, regulators, and fittings also need attention. Moisture and residue inside the gas pathway dilute CO₂, disrupt flow, and weaken carbonation. Even with the right pressure and a clean CO₂ supply, dirty systems can still produce flat drinks. Regular cleaning and line maintenance protect fizz, flavour, and equipment lifespan.
How To Improve CO₂ Levels in Your Drinks
Improving CO₂ levels is the quickest way to restore fizz, flavour, and consistency across every drink you serve. This section gives clear, practical steps that bar teams, cellar technicians, and brewery staff can apply straight away. Each action strengthens carbonation stability and stops drinks from going flat too soon.
1. Start with Clean, Beverage-Grade CO₂
Not all CO₂ is suitable for beverages. Industrial-grade CO₂ is designed for welding and manufacturing. It often contains hydrocarbons, sulphur compounds, and moisture that can weaken carbonation and introduce off-flavours.
Beverage-grade CO₂ is refined to meet stricter purity levels set by the International Society of Beverage Technologists (ISBT) and the European Industrial Gases Association (EIGA). These standards define acceptable limits for contaminants such as hydrogen sulphide, carbonyl sulphide, and moisture. All of which affect carbonation performance.
Starting with the right grade of CO₂ is essential because purity directly influences fizz stability. Clean CO₂ dissolves more consistently, holds carbonation better, and delivers brighter sensory quality. Dirty CO₂ does the opposite, creating flat pours even when pressure and temperature look correct.
2. Install a CO₂ Polishing Filter
Even certified beverage-grade gas can pick up impurities during transport, cylinder filling, or storage. Installing a CO₂ polishing filter prevents these contaminants from entering your system.
Sure Purity’s Carboguard Mini (for bars, restaurants, and fast-food chains) and Carboguard Craft (for breweries and high-volume systems) use multi-stage filtration to remove:
- Hydrogen sulphide
- Carbonyl sulphide
- Hydrocarbons
- Moisture
- Trace chemical impurities
Filtered CO₂ behaves more predictably. It dissolves cleanly into the drink and stays there longer. The benefits are immediate:
- Cleaner flavour with no chemical taint
- Better sparkle and longer-lasting fizz
- Improved foam retention in beers
- More stable pours across each keg or bag-in-box
Many venues only realise how inconsistent their CO₂ supply was after installing filtration – and seeing carbonation improve almost overnight.
3. Maintain the Right Pressure
Correct pressure is essential for controlling carbonation. Too little, and the drink goes flat. Too much, and it becomes harsh and foamy. Use these simple ranges as a guide:
- Lagers and highly carbonated beers: 100% CO₂ at 10–12 psi (0.7–0.8 bar), depending on temperature
- Stouts and certain ales: CO₂/N₂ blend at 25–30% CO₂ and 70–75% nitrogen at 25–35 psi (1.7–2.4 bar)
- Fountain soft drinks: Carbonator pressure usually between 60–80 psi (4–5.5 bar), depending on the system
Stability matters more than the exact number. Sudden pressure swings quickly drain carbonation from drinks or cause excessive foaming at the tap.
4. Keep Drinks Cold
Temperature is one of the strongest influences on carbonation. CO₂ dissolves easily in cold liquid and escapes quickly from warm liquid.
If the cellar, keg room, or syrup room is even a couple of degrees too warm, fizz fades fast. Warm storage leads to:
- Flat pours
- Weak sparkle
- Poor foam stability
- Faster staling of beer
Aim for consistent cellar temperatures between 3–5°C to preserve carbonation and improve gas absorption.
5. Test CO₂ Quality Regularly
Regular CO₂ testing confirms that gas purity has not changed since delivery. It also helps diagnose problems early.
You can use:
- Portable CO₂ purity meters for quick checks
- Inline sensors for continuous monitoring
- Laboratory gas chromatography for detailed analysis
Test whenever:
- You change suppliers
- You receive a new cylinder batch
- Customers report flat or odd-tasting drinks
- You notice pressure or carbonation inconsistencies
Testing complements filtration and gives teams confidence that their gas is clean and stable.
6. Maintain a Clean System
Even the best CO₂ in the world cannot compensate for a dirty system. Moisture, syrup residue, and microbial growth all interfere with carbonation and disrupt CO₂ absorption.
Good system hygiene includes:
- Regular line cleaning
- Inspecting regulators, valves, and fittings
- Ensuring no moisture enters the gas path
- Storing cylinders upright in a dry, cool area
A clean system supports gas purity, protects equipment, and keeps carbonation levels steady from the first drink to the last.
Best Practices for Consistent, High-Quality Fizz
Delivering reliable fizz across every drink isn’t luck — it’s the result of consistent practices that protect CO₂ quality, control pressure, and maintain system stability. These best practices help bars, breweries, and beverage venues keep carbonation levels steady and predictable.
Monitor Gas Blends
Different drinks need different gas ratios. Getting this balance right is essential for proper carbonation and mouthfeel.
- Lagers and highly carbonated beers: Always use 100% CO₂.
- Stouts and cream ales: Use a 25–30% CO₂ / 70–75% nitrogen blend to create a smooth texture and creamy head.
- Fountain drinks: Ensure the carbonator is set correctly to deliver the right CO₂-to-water ratio for strong, long-lasting fizz.
Incorrect blends cause instant problems — flat pours, excessive foam, or a mouthfeel that doesn’t match the drink’s style. Monitoring blends keeps carbonation accurate and consistent.
Check Cylinder Storage Conditions
Even perfect CO₂ can be compromised if cylinders are stored incorrectly. Poor storage introduces moisture, reduces pressure stability, and increases the risk of contamination.
For best results:
- Keep cylinders upright at all times.
- Store in a dry, cool space away from heat sources.
- Ensure cylinders are secured to prevent damage or leaks.
- Avoid areas where cleaning chemicals or moisture can enter fittings.
Simple storage habits protect CO₂ quality before it reaches the system.
Use Professional-Grade Regulators
Regulators control the pressure that drives CO₂ into the drink. Low-quality or poorly maintained regulators can cause sudden pressure swings, making drinks flat one hour and foamy the next.
Professional-grade regulators deliver stable, accurate pressure that protects carbonation. Reliable regulators also respond more smoothly to changes in temperature or system demand.
Key benefits include:
- Consistent pressure delivery
- Reduced risk of over- or under-carbonation
- Better pour control and system efficiency
Regulator performance is often overlooked, but it has a significant impact on drink quality.
Partner with Technical Specialists
Carbonation consistency improves dramatically when venues work with trained technical teams. Specialists can diagnose gas-related issues, optimise dispense settings, and recommend precise improvements for each system.
Sure Purity offers a consultative approach to CO₂ quality and beverage performance. Their expertise helps bars, breweries, and foodservice operators:
- Improve CO₂ purity through filtration
- Reduce gas-related faults
- Maintain system stability
- Optimise pour quality
- Implement long-term carbonation control strategies
Working with specialists ensures every part of the gas pathway supports high-quality fizz from keg to glass.
Benefits of Improving CO₂ Levels
Improving CO₂ levels delivers immediate and measurable gains across every part of the dispense experience. When gas purity, pressure, and system conditions are well controlled, drinks taste fresher, pour more consistently, and hold their carbonation for longer.
Better Taste and Aroma
Clean CO₂ protects the drink’s natural flavours. When gas contains no sulphur compounds or hydrocarbons, it leaves the beverage’s aroma and taste untouched. Customers enjoy a clearer, brighter flavour profile that reflects the brewer’s or brand’s original intention.
Stronger Fizz and Longer-Lasting Carbonation
Stable CO₂ levels give drinks a lively sparkle from the first pour to the last. High-quality, polished CO₂ dissolves more efficiently and holds its carbonation for longer, preventing early flatness and maintaining a stronger sensory impact.
More Stable Foam in Beer
Beer foam depends heavily on CO₂ quality. Clean, consistent gas helps form tighter bubbles and longer-lasting head retention. This improves presentation, enhances aroma delivery, and supports a smoother mouthfeel. Especially in draught beers.
Lower Waste from Flat Drinks
Flat or inconsistent drinks often end up being remade or poured away. By improving CO₂ quality and ensuring stable carbonation, venues reduce wastage across both draught beer and fountain dispense systems. Even a small drop in waste results in significant annual savings for busy sites.
Consistent Customer Satisfaction
Customers expect consistency. When every drink maintains the same sparkle, aroma, and mouthfeel, confidence grows. Improved CO₂ management leads to fewer complaints, smoother service, and a more reliable drinking experience.
Reduced OPEX and Maintenance Issues
Better CO₂ control reduces strain on regulators, carbonators, and dispense equipment. Clean gas prevents moisture-related faults, reduces downtime, and extends the life of key system components. Venues benefit from lower operational costs and fewer reactive maintenance visits.
Carboguard filtration is used by leading beverage brands to stabilise carbonation and protect product quality. Its multi-stage CO₂ polishing technology removes the impurities that cause flatness, harsh flavours, and unstable pours — helping operators deliver a better drink every time.
Final Thoughts
Gas quality is the foundation of carbonation quality. No matter how well a drink is brewed or blended, its fizz depends on the purity and consistency of the CO₂ behind it. When gas is clean, stable, and delivered at the right pressure, drinks stay lively, aromatic, and refreshing. When it’s not, fizz fades fast – taking flavour, foam, and customer satisfaction with it.
Managing CO₂ quality gives bars, breweries, and foodservice operators far more control over drink performance. It reduces waste, improves presentation, and ensures every pour meets the standard customers expect.
Explore how Sure Purity’s Carboguard Mini improves CO₂ purity and helps you achieve the best fizz, flavour, and carbonation in every drink.
