Wednesday 11 January 2023

Beginner FAQ: Cleaning & Sanitising - What's the Difference?

No doubt as you embark and continue on your beer brewing journey, you'll see the terms "clean" and "sanitise" thrown around quite a lot. It's no secret that cleaning and sanitation are the less glamarous but crucially important aspects of making your own beer - and although the two are closely related, it's good to have an understanding of both these key principles, how they relate to each other and what the difference between them is.


As the name suggests, and as most people are probably aware, cleaning involves removing dirt, debris and other foreign matter from objects and surfaces. It's no different when we're talking about brewing. All equipment used in the brewing process - from kettles, spoons, bottles, kegs, bowls, cups, thermometers, fermenters, siphons, hydrometers, and silicone tubes should all be clean - that is, have no visible signs of contaminants on them. In a nutshell, cleaning targets the dirt and foreign matter you can see.

An important consideration when cleaning beer brewing equipment is what cleaning product or chemicals you use. Powdered Brewery Wash (PBW) is a common and popular choice - we use it ourselves as it is (as the name suggests), designed for use in breweries and brewery related cleaning. It's an alkali (ie. non-acidic) cleaner so is generally safe on skin and soft metals like aluminium and stainless steel, as well as plastics and rubbers like the gaskets, seals and other pieces of equipment commonly found in breweries and homebreweries.

The major ingredient in PBW is sodium percarbonate, which can also be purchased and used as a cleaning agent on it's own. It's also a common ingredient in household laundry cleaners like Napisan.

If you want to use another sodium percarbonate based cleaner that isn't pure sodium percarbonate, or PBW, you can certainly do so, but an important thing to keep in mind is to not use any cleaners that are scented. As you could imagine, if you clean using a scented detergent some of the scented perfume used will likely remain on the surface of the object you've cleaned afterwards and then potentially leach into future brews. Lavender scented beer anyone? No, thank you.

Cleaning with PBW or sodium percarbonate products works best in warm or hot water. Be careful when cleaning delicate plastic parts like PET plastic based fermenters to not exceed the recommended temperature for fluids stored inside them - usually around 50°C. These products do work in cold water but a little more scrubbing is required compared to using warmer water. 

Speaking of scrubbing, it's also a good idea to use non-abrasive sponges when cleaning to minimise scratching, particularly when dealing with plastic parts like plastic based fermenters. Scratches, whilst being unsightly can also allow a build up of dirt and other microbes within them and can be difficult to clean (and sanitise) next time around.


Sanitising is the next step that needs to be done after cleaning has been completed and all the visible dirt and contaminants have been removed. Sanitising is the process of removing the contaminants that you can't see as they're at a microbial level.

If a surface looks clean, then it's ready to be sanitised, and sanitising is as simple as spraying or submerging the surface in a solution that will kill any germs or bacteria that are present. It's important that the surface is clean first, as you can't sanitise dirt.

This of course requires some special chemicals to do so, with the most popular being phosphoric acid based sanitisers like Star San. Other chemicals like iodine or bleach can also be used, but remember to avoid scented products (especially when dealing with bleach) to avoid the previously mentioned risk of scents and fragrances remaining on sanitised surfaces and leaching into your future beers.

When using bleach it's also important to remember to rinse thoroughly afterwards as even unscented bleach can leave a residual coating.

What we use, and our recommendation for other homebrewers is to use phosphoric acid based sanitisers. There are a couple of things worth mentioning and pointing out though with regards to these products.

Firstly, they are generally safe to use if you follow some simple safety precautions when using them. Gloves are a good idea as it will burn a little if you get undiluted phosphoric acid on your hands.

Also be careful not to spill or place the bottle containing the undiluted phosphoric acid on any finished hard surfaces - like benchtops as it will eat into them and leave a permanent mark/stain. Countless brewers have been caught out by this one and marked their nice stone bench tops with phosphoric acid.

When diluted though, these products are safe on surfaces and won't do any harm if coming in contact with skin. Mix up a batch in a spray bottle as a handy, ready to go option for quickly sanitising objects and surfaces on the go.

Most phosphoric acid based sanitisers are considered "no rinse" so don't need to be rinsed off with water after being used, making them fast and easy to use. Foaming sanitisers like Star San can leave quite a lot of residual bubbles and foam after being used, but there's a common saying "don't fear the foam" - it's fine to leave it there and won't lead to any problems or off flavours being imparted.

Always follow the recommended dilution rates as per the instructions on the packaging, as mixing it up too strong may lead to residual acidic smells and flavours, and mixing it up too weak may render it ineffective at sanitising.

As well as a spray bottle, you can also mix up any amount you desire in a bucket or other vessel and simply submerge whatever you need to sanitise in the solution.

Phosphoric acid based sanitisers work in as little as 30 seconds so don't need long exposure times to be effective.


As you can see, cleaning and sanitising are indeed very different from one another, but both are critically important to ensure you're getting the best results possible from your brewing.

Inadequate cleaning and sanitising practices can lead to an infection occurring - a concept that strikes fear into the heart of just about all brewers. This can be daunting and intimidating, particularly for new brewers, so it's important to get into the habit of cleaning and sanitising everything. 

Thankfully, the products you need to do this are affordable and readily available, so with a little care you can pretty well eliminate your risk of contamination occurring.

Remember, if it looks clean, it probably is, but it isn't sanitary until you've sanitised it. Give it a quick spray with some diluted phosphoric acid sanitiser and you're set!

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