Caustic Crisis: 5 Ways to Stop Wasting Caustic in Craft Breweries

Caustic soda is the workhorse of brewery cleaning. It is also one of the most wasteful chemicals in the building. The variance between breweries is wide: some are running tight, optimised CIP programmes with near-zero caustic waste; others are disposing of usable caustic after every clean as a matter of habit. This article covers five specific changes that address the most common sources of caustic waste in a UK craft brewery.

1. Stop the pitch and ditch

Disposing of caustic after every CIP cycle is the single largest source of caustic waste in most breweries. The reasons breweries do it are understandable: it is operationally convenient, and there is a comfort in starting each clean with fresh chemical. But the cost is real. Caustic that still has working concentration is being sent to drain and replaced with new chemical for the next cycle.

The fix is a caustic recovery system. At its simplest, you need:

• A holding vessel of approximately 5% of your fermenter volume (a second-hand tank works)

• A centrifugal pump to return caustic from the cleaning location to the vessel

• A titration kit to check concentration before reuse

• Optional: a second tank on the same skid to recover post-caustic rinse water separately

The vessel does not need to be pressure rated, but it cannot be open. Making the setup mobile on a skid adds flexibility if you are cleaning across multiple areas.

What to expect from caustic recovery

A basic recovery setup typically reduces caustic consumption by 40 to 60% per year. A semi or fully automated CIP set can achieve up to 95% reduction. The affordable recovery approach pays back in months, not years. To calculate your own payback, take your current annual caustic spend, apply the relevant percentage reduction, and compare against the cost of the vessel, pump and fittings.

Conductivity monitoring

Titration kits are the minimum for checking concentration before reuse. If budget allows, an inline conductivity meter is a significantly better investment. Conductivity gives you a continuous, real-time reading of caustic strength without the manual test step, and enables automated dosing top-up when concentration drops below target. Kits are available from your chemical supplier, often at low cost or free, and take under a minute to use.

2. Understand CIP theory to optimise concentration

Fear is a legitimate factor in brewery cleaning programmes. A failed CIP has serious consequences: product loss, sensory defects, brand damage and, in the worst case, a recall. The phrase "we have always done it this way" reflects a rational caution about changing something that works.

But that same caution can calcify into programmes that use significantly more chemical than the cleaning outcome requires. The four principles of CIP are:

• Time: contact duration between chemical and surface

• Temperature: higher temperatures generally increase cleaning efficacy

• Concentration: the chemical strength of the cleaning solution

• Mechanical action: flow velocity and turbulence against the vessel surface

These four factors interact. Increasing any one can compensate for a reduction in another. A well-understood CIP programme uses this relationship deliberately rather than defaulting to the highest concentration out of habit.

A useful rule: any CIP requiring more than 1.5% v/v NaOH should be justified by the soil type or vessel geometry. Standard fermenters on a regular cleaning interval do not need to be cleaned at 2% or above. Reviewing your caustic concentrations against actual soil loads is usually one of the quickest ways to identify waste without compromising hygiene.

3. Match the CIP regime to the vessel

One CIP programme does not fit all vessels. Fermenters, bright beer tanks, the brewhouse and packaging equipment each have different soil types, surface areas, geometry and cleaning requirements. Running the same caustic concentration, temperature and contact time across all of them is almost always wasteful on some and potentially inadequate on others.

The practical step is to audit each CIP area independently and set its own parameters: caustic concentration, contact time, temperature and rinse protocol. The brewhouse kettle accumulates different soils than a fermenter. A canner or filler has different requirements again. Writing individual procedures for each area, rather than one universal programme, reduces both chemical waste and the risk of applying the wrong process to the wrong vessel.

4. Calculate correctly and titrate every time

Because CIP is routine, it is easy to fall into adding the same volume of caustic by habit rather than by calculation. This is especially common in pitch-and-ditch operations where the same amount gets added at the start of every cycle regardless of vessel volume or soil load.

The correct calculation accounts for the NaOH strength in your specific caustic soda product, not just the volume of caustic soda added. When brewers discuss CIP concentration, the percentage refers to NaOH in solution, not the percentage of caustic soda. The formula is:

Caustic to add (L) = [Water volume (L) x desired NaOH concentration (%)] / NaOH strength in caustic soda (%)

Titration confirms the calculation is correct, the product strength matches the specification, and your measuring process is accurate. A dropper-based titration kit using Phenolphthalein indicator and a standard-strength acid takes under one minute and is available from any chemical supplier. Use it as a check rather than relying solely on the calculated volume.

5. Explore alternatives to caustic

The long-term option is to reduce dependence on caustic entirely. As an industry, the relationship with caustic soda is partly one of familiarity and partly one of commercial inertia. It has been the default brewery cleaning chemical for decades. But there are alternatives that are now established enough to evaluate seriously.

Enzyme-based cleaners

Enzymatic cleaning has been available to the brewing industry for some time. Adoption in craft brewing has been slow, partly because of concerns about cost and temperature requirements compared to caustic. The case for enzymes has strengthened as their formulations have improved. Murphy and Sons have published detailed technical work on enzymatic CIP in brewing applications, and their research is worth reviewing if you are considering a trial.

Acid-based detergents

Newer acid-based detergent formulations are emerging as a direct caustic alternative. NOPAC (also marketed as SOPURCLEAN by Holchem/Kersia) can clean brewery vessels without caustic for most soil types, removing the need for CO2 purging post-clean. It also functions as a sanitiser, eliminating the separate PAA step, though sterile water is still required for rinsing. Caustic shots are still recommended for krausen rings. This is not a simple drop-in replacement, but it is worth trialling if caustic reduction is a strategic goal.

Whichever alternative you trial, feed the findings back to your supplier and share results with other brewers. The more data that circulates in the industry, the faster these alternatives can improve and become accessible for breweries of all sizes.

What a brewery CIP review finds

A structured CIP review starts with your current chemical spend and cleaning programme documentation, then audits each CIP area against the four principles: time, temperature, concentration and mechanical action. It identifies where programmes are over-specified relative to the soil load, where recovery systems could be installed, and where concentration calculations are not being followed consistently.

The output is a prioritised set of changes with estimated savings for each. In most craft breweries, the combination of caustic recovery and concentration optimisation delivers 40 to 60% chemical cost reduction within the first year.

Get a free brewery CIP assessment to identify where your caustic spend is going and what a realistic reduction looks like for your specific equipment and process mix.