In home brew jargon, ‘sterilisation’ means knocking back the population of microbes so that they can’t get to work on your brew. For the best results use a product that cleans as it sterilises, and make sure you rinse everything at least twice after using it.
Why is it important to sterilise equipment?
Whether you’re making beer or wine, your brewing liquid (known as ‘wort’ in home brew jargon) is designed to be perfect for the rapid growth of yeast. Unfortunately, it’s perfect for other microbial growth too. The environment is full of bacteria, wild yeasts, fungi and other microscopic nasties that can’t wait to ruin your beautiful brew. If you don’t sterilise your kit well, you can expect one of several problems:
- ‘Off’ flavours or aromas. Vinegar, mouse pee, wet cardboard, TCP… the exact smell depends on what nasty has invaded your brew, but none of them are good!
- A scummy, powdery or mouldy film on the surface of your brew.
- The appearance of slimy or oily ‘ropes’ in your brew
The Golden Rule
Types of steriliser
Chlorine-based sterilisers such as VWP are the most popular products on the home brew market, because they don’t release irritating fumes and are easily blended with cleaning agents.
Sodium metabisulphite is a traditional steriliser which generates sulphur dioxide gas when mixed with water. Although effective, there are problems with using it: the powder is harmful to skin, and the sulphur fumes that it produces when mixed with water are very irritating and should not be used by anyone with chest conditions such as asthma. Once opened, the powder fuses into a hard lump within a few days which makes it difficult to use.
Active oxygen based sterilisers are relatively new, working in a similar way to chlorine sterilisers. Some manufacturers claim their products don’t need to be rinsed off, but these cannot contain detergents and so are not likely to clean residues off glass effectively.
And finally… plain old boiling water! Boiling water isn’t as reliable as chemical cleaning agents, and can shatter glass equipment. But if you just want to sterilise a ladle or brewing spoon, or forgot to sterilise the caps for your beer bottles, boiling water will do the job.
We recommend VWP powder, a chlorine-based product that cleans and sterilises in one go. Just soak, drain and rinse. VWP can also be used as a household cleaner/disinfectant.
How to sterilise home brew and wine making equipment
- Get ALL the equipment you’ll need ready. Also fetch a plastic cutting board or spare fermenting bucket lid, to act as a clean surface to put your sterilised equipment onto.
- Make up your sterilising solution as per the packet instructions, and put it into a suitable container.
- Sterilise the items in batches, starting with the plastic board or lid. Soak, rinse, rinse again, leave to drain.
Tips for effective sterilisation
- Old fashioned cleaning is just as important as sterilisation, so always use a combined cleaner/steriliser.
- Do your sterilisation just before you need the equipment. The longer your kit sits out, the more likely it is to get contaminated with airborne bugs.
- Rinse everything at least twice after sterilising it.
- Drain, don’t dry. You don’t want to introduce bugs from a drying cloth.
- If you’re using swing top bottles, take them to pieces so that all the crevices are cleaned. If the seals are cracked at all, don’t use them.
- It can be difficult to get the inside of demijohns and carboys clean without the use of a cranked brush. If you use a lot of these containers, consider buying a carboy cleaner, which fits onto an electric drill.