Brewery Gas Efficiency: 5 Ways to Stop Wasting Natural Gas

Natural gas is typically the second largest utility cost in a UK craft brewery, after electricity. At 2025/26 industrial gas prices of £0.05 to £0.08 per kWh, a brewery at the 42 kWh/hl Brew Resourceful benchmark producing 10,000 hl per year is spending £21,000 to £33,600 on gas annually. Breweries running without heat recovery or on ageing boilers can spend two to three times that for the same output.

Most of that spend passes through a handful of systems: the steam boiler, the brewkettle, the hot liquor tank and the CIP heating circuit. The savings are in the same places. This article covers the five most common sources of gas waste in a craft brewery, with specific numbers and practical fixes for each.

How much gas does a brewery use? UK benchmarks

Gas consumption in a brewery is measured in kilowatt-hours per hectolitre of packaged beer (kWh/hl), the same unit used for electricity. Brew Resourceful's UK craft brewery benchmark is 42 kWh/hl, based on data from breweries that have completed a structured energy review.

The spread across the industry is wide:

• Best in class: below 20 kWh/hl

• Good performance: 35 to 42 kWh/hl

• Brew Resourceful benchmark: 42 kWh/hl

• Upper end users: 42 to 60 kWh/hl

• Significant users: 60+ kWh/hl

  
  

Breweries with heat recovery, newer boilers, and tight condensate return systems tend to sit in the good-performance band.

Direct-fired operations without heat recovery typically run at 60 kWh/hl or above. For most UK craft breweries, gas accounts for 25 to 40% of total utility spend.

Where is natural gas used in a brewery?

In a typical craft brewery, gas use breaks down roughly as:

• Wort boiling and heating: 35 to 50%

• Hot liquor heating: 20 to 30%

• CIP: 10 to 20%

• Utility inefficiency: 10 to 40%

• Space heating: 2 to 10% (seasonally variable)

  
  

Some breweries also use gas for steam-in-place sterilisation, lauter heating and hop pellet processing. The balance between these uses varies by brewery design, but the kettle and HLT heating consistently represent the majority of consumption.

1. Steam boiler losses and poor condensate return

The boiler is the centre of gas consumption for most steam-heated breweries. Most boilers often operate at 75 to 90% thermal efficiency; poorly maintained can operate at just 60% thermal efficiency. This increases your gas usage before anything is even heated.

Condensate return

Every kilogram of steam that is not returned as condensate must be replaced with cold mains water, heated from ambient temperature to steam pressure. Poorly maintained steam traps, uninsulated return lines or missing condensate recovery from remote processes can drop return rates to 40 to 50% in older systems. Breweries targeting best-in-class performance aim for 80% or above. Each 10 percentage point improvement in condensate return rate reduces boiler gas by approximately 5 to 7%.

Blowdown losses

Boilers require periodic blowdown to control dissolved solids in the water. Uncontrolled or excessive blowdown discharges hot water that has already been heated, wasting both the energy and the treated water. Automatic TDS control systems pay for themselves quickly in high-usage applications. A simple heat exchanger on the blowdown line can recover 60 to 80% of the heat otherwise lost to drain.

2. Uninsulated pipes, vessels and tanks

Heat loss from uninsulated surfaces is a continuous drain that most breweries underestimate. A 100mm uninsulated steam pipe at 150°C loses approximately 150 to 200 watts per metre to the surrounding air. A 10-metre run of bare pipe operating 8 hours a day for 300 days loses 360 to 480 kWh per year, costing £18 to £38 per run at current gas prices.

The same applies to hot liquor tanks, CIP buffer vessels and any vessel holding heated liquid for extended periods. Tanks are often insulated on the body but not the lid, which can account for 20 to 30% of total tank heat loss. A full insulation survey of your steam and hot water system is typically one of the highest-ROI activities in a gas efficiency programme, with payback periods of under 12 months on most identified gaps.

3. Inefficient kettle firing and heat recovery

The kettle is the single largest user of gas in most breweries. Heating wort from mash temperature to boiling, maintaining a rolling boil for 60 to 90 minutes, and then cooling represents a substantial thermal load that repeats every brew cycle.

Wort heat recovery

Vapour condensers (sometimes called grant heat exchangers or knockout heat exchangers) capture the heat from boiling vapour or from hot wort during cooling and transfer it to the next brew's liquor. A well-designed heat recovery system can reduce kettle gas consumption by 15 to 25% depending on boil intensity and system efficiency. The investment is typically £5,000 to £20,000 depending on brewery scale, with payback of 2 to 4 years at current gas prices.

Boil intensity

Breweries routinely overboil. A vigorous 8 to 10% evaporation rate was historically considered necessary for DMS reduction, but modern base malts and covered boiling vessels achieve the same result at 4 to 6%. Reducing evaporation rate from 10% to 5% cuts kettle gas consumption by approximately the same proportion for the boil phase. This costs nothing to implement and requires only a burner adjustment and quality check.

4. Hot liquor and CIP heating losses

Hot liquor tanks in many breweries run at a permanently elevated temperature, maintaining 80 to 85°C around the clock regardless of whether a brew is in progress. The standing heat loss from a continuously heated HLT represents a significant gas cost for a small number of brewing days per week.

The fix is simple: set the HLT to heat on demand rather than maintaining temperature continuously. Most brewery control systems can support scheduled heating profiles.

CIP circuits present a similar opportunity. Many breweries heat CIP caustic and acid to higher temperatures than are operationally necessary. Caustic at 65 to 70°C is effective for standard brewery CIP; running at 80°C adds cost without improving cleaning performance on most soil types. CIP heat recovery, where the heat from spent cleaning solution is transferred to the next CIP charge, is viable in higher-volume operations and can reduce CIP gas by 30 to 40%.

5. Lack of metering and monitoring

Breweries that cannot see where gas is going cannot prioritise where to reduce it. Many UK craft breweries have a single gas meter for the whole site, which means the boiler, kettle and space heating are all combined in one number. Without sub-metering, it is impossible to distinguish a boiler performance problem from a change in production volume.

The minimum useful monitoring setup is a sub-meter on the boiler and a production log that records kWh/hl per brewing week. That alone enables variance analysis: if consumption per hl rises, you know something has changed and can investigate while the cause is recent.

Getting metering in place

1. Install a sub-meter on the boiler gas supply (typically £300 to £800 for a pulse meter with data logging)

2. Record gas consumption against production volume weekly, not just from monthly utility bills

3. Set a baseline over 8 to 12 weeks, then review variances against brew schedule and ambient temperature

4. Add sub-meters for the kettle burner and space heating if the boiler meter reveals unexplained consumption gaps

Energy monitoring software is optional; a simple spreadsheet with weekly kWh and hl totals gives you the data you need to start managing consumption rather than just paying for it.

How a brewery gas audit works - and what it finds

A brewery gas audit starts with your billing data and current production volumes to establish your kWh/hl baseline and benchmark it against comparable sites. It then moves to a site survey: walking the steam and gas distribution system, recording insulation status, checking boiler maintenance records, reviewing condensate return rates and logging set-points across the heat-using systems.

The output is a prioritised findings report. It separates the no-cost fixes (set-point changes, boil intensity reduction, HLT scheduling) from the capital investments (heat recovery equipment, boiler upgrade, sub-metering), and gives a payback calculation for each. Typical findings for a UK craft brewery include: 15 to 25% saving from set-point and scheduling changes, 10 to 20% from insulation improvements, and 15 to 25% from heat recovery installation where not already in place.

Gas efficiency savings at Vault City

Vault City Brewing in Edinburgh worked with Brew Resourceful as part of a broader energy efficiency programme. The project identified and addressed gas-related losses across steam generation, kettle firing and process heat, as part of a six-technology investment programme supported by Scottish Enterprise.

Across the full project, Vault City achieved £944,000 in projected lifetime savings and avoided 1,937 tCO2e of emissions, with an average payback period of 2.9 years across all technologies invested in. Gas efficiency improvements were a material component of the overall saving.

How do your brewery gas costs compare?

The benchmarks above give a directional read. Breweries above 55 kWh/hl should focus first on process-based changes before investing in CAPEX. Those already in the 35 to 55 kWh/hl good performance band typically find the remaining gains come from sub-metering to identify which processes are still running inefficiently and CAPEX.

A free brewery benchmarking report gives a more precise comparison against breweries of similar scale, covering gas per hl alongside electricity, water and overall cost per hl.

Get a free brewery gas efficiency assessment to identify where your gas losses are occurring and what a realistic reduction looks like for your specific equipment and process mix.