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


So this week we are here to talk about the worst tasting soda on the market, Caustic Soda. First take a step back and think about caustic for a minute, it’s a product intrinsic to arguably the most essential aspect of brewing – cleaning – yet it reacts horrendously with the most produced and used gas in brewing. It’s kind of mad really.

None-the-less we certainly churn through caustic. The variance between breweries can be substantial too. In my life I have seen some great CIP programmes and some not-so-great ones. In this article I hope to share the good I have seen whilst addressing the bad. So here goes!

Caustic Soda Bottle

1. Switch the Pitch & Ditch 🙅‍♀️

I totally get why a lot of breweries do this. I’ve certainly been a part of breweries that do it, ultimately it is really f**king convenient. But it’s also a dreadful habit. Here's why

  • Very expensive to throw usable caustic down the drain

  • High pH wastewater is super bad for the wastewater system

  • It’s bad business practice economically and environmentally

There are a couple of options to stop the pitch and ditch.

The Affordable Approach

Buy an appropriate holding vessel. Any second-hand tank of an appropriate size will do (~5% of fermenter size). It doesn’t need to be pressure rated, but it can’t be an open vessel.

*Even cheaper, use an old tank laying around

Get titration kits from your chemical supplier (this is a MUST have)

*If you have a bit of extra budget, conductivity is King

An addition centrifugal pump is required for returning caustic from cleaning location to caustic holding tank.

Recommended Optional Extras – mount the tank and pump to a SKID and make it mobile. If possible add an additional tank to this SKID (2 tanks total) so you can reuse your post caustic first rinse water for additional gains.

The 'Best' Approach

If budgets are capable, buy a semi/fully automated CIP set. The payback is greater, they are safer and overall better than an affordable alternative.

The Paybacks

With your in-house CIP set you can expect savings of 40-60% of caustic per year and upwards of 95% with an automated CIP set.

The affordable approach is absolutely cost effective and payback is several months not years. The CIP set has a longer payback but the lifetime value of this investment is significantly higher as once it has paid back, your gains of up to 95% caustic reduction is significant.

Of course paybacks are bespoke to your process, equipment etc.

To calculate take your caustic cost, reduce it by these percentages and calculate your payback based on the investment required.

2. Fear over Theory 😨

The consequences of an improper CIP are dire. Loss of time, loss of product, sensory impacts, brand damage and the dreaded product recall.

Therefore, fear can play an important role in a breweries CIP regime. Have you ever heard these phrases:

‘Well we haven’t had an issue so far’

‘This is what we have always done’

These can be classic examples of fear overruling theoretical understanding. This is the cornerstone of an unoptimised CIP regime.

CIP meme
Seriously Niche

Understanding the 4 principles of a CIP is such a great skill for brewers to have, it allows them to optimise CIPs and make integral game-time decisions when a CIP doesn't go to plan!

They are quite self explanatory but understanding each of the 4 principles in full is integral to being able to use it for your advantage. I have an episode of a podcast that will be released this month that covers this topic in good detail. If you want to be alerted when it's released please subscribe here

So knowing them is one part, the other is manipulating them to for CIP optimisation. Think of the optimal CIP as 100% this chart shows each segment has equal value, but if you increase one you can decrease another. So you can see how you might be able to decrease your caustic consumption.

A great rule to live by is any CIP over 1.5% v/v NaOH needs to be justified.

3. Horses for Courses 🏇

One size does not fit all. Every CIP area should have its own CIP regime with it’s own manipulation of the 4 Principles of CIP.

You shouldn't clean fermenters the same way you clean a canner/brewhouse/BBT

4. Calculate & Titrate 🧪

Because of the intense frequency of caustic cycles in our day-to-day lives. It can be so easy to get into a routine of adding the same amount of caustic every time. Even more common with the pitch and ditch methodology.

But you should refresh your calculation and ensure your adding the correct amount by titration. There can be some confusion with calculating NaOH in your caustic solution. The dreaded volume/volume (v/v) vs weight/volume (w/v).

In simplest form you need to be accounting for the concentration of NaOH in your caustic soda. So when we discuss a % caustic concentration in fact it is the % of NaOH in solution rather than the % of the caustic soda (where strength of NaOH varies).

So your caustic calculation should look like this

Caustic to add in L = (Water Volume (L) * Desired final NaOH Concentration (%))/NaOH Strength in Caustic Soda (%)

To check this, titration is key. This will show your calculation is correct, the caustic % you buy is correct and importantly your measuring process is correct. The process is a simple dropper test with a kit comprising of Phenolphthalein Indicator and a particular strength acid. Kits are available from all chemical suppliers (often free, sometimes around £10) and take less than 1 minute to complete.

5. Stop it all together 🚫

One reliable way to lower your caustic consumption is to replace it. As mentioned right at the start, as an industry probably need to move on from caustic. It’s been a faithful companion but with the spotlight on sustainability it’s time we let the old dog go.

Whether the staple cleaning product of the future are enzymes, acid based detergents or something else. We need to move on.

Enzymes are nothing new to the market but seldom has it been adopted into the craft brewery. Concerns over price and temperature requirements have been at the forefront.

Again acid based detergents are nothing new but their development is showing strength. There is a new acid-based detergent making waves from Holchem/Sopura (a.k.a Kersia) called NOPAC/SOPURCLEAN.

This acid can clean without the need of caustic (although caustic shots are recommended for krausen rings) so removal of CO2 is not needed. It also does not need PAA as it’s a sanitiser to (although sterile water is required for rinsing).

It’s still fairly new to the market and certainly isn’t a quick, easy switch from caustic but it’s certainly worth exploring.

We need to trial and adopt these chemicals/enzymes share the findings with fellow brewers and feedback to the supplier, together we can do it!

If you have any experiences, or are looking to trial these products let me know!

That’s it for this week.

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Take care out there

Chris 🤘

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