What Is the Best Water for Brewing Beer? Tap, Bottled or RO

The best water for brewing beer is water you understand and can control. Before we get anywhere near adjusting or treating your water, we need to know what we’re starting with.

Brewers call the water used to make beer “liquor”, and the source you choose – whether that’s tap water, bottled water or reverse osmosis (RO) water – will affect mineral content and, ultimately, your finished beer. In this guide, we’ll break down the best water for beer brewing, compare the main options, and show you how to get started with confidence.

Table of Contents

• What Is the Best Water for Beer Making?
• Brewing Beer With Tap Water
• Brewing Beer with Bottled Water
• Brewing Beer with Reverse Osmosis Water
• Tap vs Bottled vs RO Water for Brewing Beer

What Is the Best Water for Beer Making?

For most brewers, the best water for beer making is clean, good-tasting tap water that has been treated to remove chlorine or chloramine. This gives you a reliable and accessible starting point without needing to overcomplicate your process.

A good starting point for most homebrewers is:

• Use tap water if it tastes good to drink
• Treat your water with Campden to remove chlorine or chloramine
• Don’t worry too much about mineral adjustments straight away
• Focus on consistency from batch to batch

Bottled water can be a simple alternative if your tap water is not suitable, while reverse osmosis (RO) water is best suited to brewers who want full control over mineral content and water chemistry. Each option has its place, but in most cases, starting simple and making small adjustments will give you the best results.

Brewing Beer With Tap Water

In most cases, tap water is a perfectly good option for brewing beer. For many homebrewers, it’s the most accessible and cost-effective source of water for beer brewing.

Best for: most homebrewers with good-quality local water

The main thing to consider is taste. If your tap water tastes good to drink, it will usually work well for brewing beer. If it doesn’t, those flavours are likely to carry through into your finished beer, so it’s often better to choose another source.

Even where the general supply is good, it’s worth being aware of things like domestic water softeners. These can add sodium and leave a slightly salty character, which is not ideal for most beer styles.

If your water is suitable, there are some clear advantages. It’s easy to access, low cost, and there’s something to be said for local character – your brewing water reflects your area, which can subtly influence the flavour of your beer.

Understanding your tap water:

Tap water varies depending on location, and the key difference comes down to mineral content and water chemistry. This affects things like alkalinity, pH and overall brewing performance.

To get a clearer picture of your water for brewing beer, it’s a good idea to use a water report. You can either:

• Request a free report from your local water supplier
• Use a brewing water analysis service such as Murphy & Sons for a more precise reading

Murphy & Sons offer an affordable homebrewing water analysis service — you simply send them a small sample, and they provide a detailed, targeted report on your water. This gives you a much clearer view of exactly what’s coming out of your tap, rather than relying on generalised local data.

A detailed report will include the main values brewers look at:

• Calcium (Ca)
• Magnesium (Mg)
• Sodium (Na)
• Sulphate (SO₄)
• Chloride (Cl)
• Alkalinity (often shown as bicarbonate, measured as CaCO₃)
• pH

These are usually measured in ppm or mg/L, and pH is given as a number (for example, around 7 for neutral water). You don’t need to act on all of these straight away, but understanding what’s in your water is the first step towards improving consistency.

An alternative is to use a generic water report from your supplier. In the UK, water companies provide these free of charge – usually under “water quality” on their websites – and they are typically updated at least once a year.

However, these reports don’t always reflect what’s coming out of your tap exactly. Filtration systems, water softeners, pipework and even property-specific factors can all affect your final water profile. That’s why an individual report is often the more reliable option for brewing.

Removing Chlorine and Chloramine:

Most domestic water supplies contain chlorine or chloramine to keep the water safe to drink. Even in very small amounts, these can cause unwanted flavours in beer, often described as medicinal or chemical.

The simplest way to deal with this is to treat your brewing water with Campden (sodium metabisulphite).

• Around 0.25g will treat 25 litres of water
• It won’t leave any flavour behind
• It works best if added a few hours before brewing (overnight is ideal)

This is one of the easiest and most effective water treatment steps you can take, and it makes a noticeable difference to finished beer quality.

You can browse our full range of water treatment products to adjust mineral balance and improve brewing consistency.

Brewing Beer with Bottled Water

Bottled water is a simple and reliable alternative to tap water for brewing beer, especially if your domestic supply isn’t ideal. It can offer more consistent water quality and removes some of the uncertainty around your starting point, but it does come at a higher cost.

Best for: simplicity and consistency without needing water treatment

One of the main advantages of bottled water for beer brewing is that the mineral content is clearly listed on the label. This gives you a clearer picture of your water for home brewing, including calcium, magnesium, sulphate, chloride and overall mineral balance.

That said, it’s still worth checking the label each time you buy. Different brands can vary significantly in mineral content, and in some cases, even the same brand can change slightly between batches. This means bottled water is not always as consistent as it first appears.

Most bottled waters have high purity and contain little to no chlorine or chloramine, which removes one of the main issues associated with tap water. However, some brewers still choose to treat their water with Campden as a precaution.

• Around 0.25g of sodium metabisulphite will treat 25 litres of water
• It won’t affect flavour when used at this level

In practice, bottled water works well as a straightforward option if you want to avoid dealing with water chemistry early on, but the cost can add up over time compared to other water sources.

Brewing Beer with Reverse Osmosis Water

Brewing with reverse osmosis water gives you one of the most controlled starting points for brewing beer, as the filtration process removes almost all minerals and impurities. This creates a very high-purity, osmosis filtered water that acts as a blank slate for your brewing.

Best for: brewers who want full control over water chemistry and consistency

RO systems work by filtering your tap water through a membrane, removing dissolved minerals, chlorine and other compounds. The result is very high-purity water with almost no mineral content – often described as a “blank slate” for brewing.

If you’re looking to get started, you can explore our range of reverse osmosis systems designed for homebrewing setups.

Building Your Water Profile:

Because RO water contains virtually no minerals, it’s important to add them back in before brewing.

Without minerals, the water is extremely neutral — which might sound ideal, but in practice it leads to flat, bland beer. Minerals such as calcium, sulphate and chloride are essential for flavour, mouthfeel and fermentation performance.

When brewing with RO water, you can adjust mineral balance and water chemistry to suit different beer styles, giving you much more control than tap or bottled water.

To build your water profile, you can use brewing salts and water treatment products to adjust mineral balance and dial in your water chemistry.

Consistency and Control:

One of the biggest advantages of brewing with reverse osmosis water is consistency.

• Tap water can vary depending on location and season
• Bottled water can vary between brands and batches
• RO water remains consistent once filtered

This consistency makes it easier to repeat recipes and refine your process over time, as your water profile stays stable from batch to batch.

Things to Consider:

While RO water offers a high level of control, there are a few practical trade-offs to keep in mind:

• Upfront cost: RO systems are more expensive than using tap or bottled water
• Maintenance: filters need replacing over time
• Water waste: typically around 3 litres of waste water for every 1 litre of purified water
• Time: producing enough brewing water can take time, so it’s often best to run your system in advance – many brewers prepare their liquor the night before

Some brewers choose to reuse the waste water for cleaning to reduce the overall impact.

An alternative to running your own RO system is using a service like Spotless Water, which provides de-mineralised water ready for brewing. It’s essentially a self-service filling station for purified water — a bit like a petrol pump for RO water – and can be a simple, cost-effective option if you don’t want to install your own filtration setup at home.

You can then transport and store the water in containers such as our 20 Litre No Chill Cubes before building your water profile with your chosen mineral additions.

For regular brewing, the cost and effort can balance out over time, but it’s worth factoring in when deciding if RO water is right for your setup.

Handling and Storage:

RO water is highly pure, which means it behaves differently to standard tap water.

Because of its very low mineral content, it will absorb carbon dioxide from the air over time. This forms a weak acid, which can gradually lower the pH of your brewing water.

For best results:

• Use RO water relatively soon after producing it
• Ideally within 24 hours
• Store it in a sealed container where possible

This helps maintain a more stable water profile before brewing.

Tap vs Bottled vs RO Water for Brewing Beer

When choosing the best water for brewing beer, the right option depends on how much control you want and how simple you want your process to be.

Tap Water:

Best for: most homebrewers and everyday brewing

Pros:

• Easy to access and low cost
• Can produce excellent beer with minimal treatment 
• Reflects local water profile and character

Cons:

• Mineral content varies by location 
• Often requires chlorine removal 
• Less control over water chemistry

Bottled Water

Best for: simplicity and consistent starting point

Pros:

• Clearly labelled mineral content
• Generally free from chlorine or chloramine
• More consistent than tap water in many cases

Cons:

• Higher cost, especially for regular brewing 
• Mineral balance can still vary between brands or batches
•  Less flexible than building your own water profile

Reverse Osmosis (RO) Water:

Best for: full control over water chemistry and repeatability

Pros:

• Very high purity and consistency 
• Complete control over mineral content and water profile
•  Ideal for dialling in specific beer styles

Cons:

• Higher upfront cost for equipment 
• Requires adding minerals back in 
• Produces some water waste and takes time to prepare

For most homebrewers, starting with treated tap water is the easiest option, with bottled or RO water becoming more useful as you look for greater consistency or control.

Final Thoughts: Choosing the Best Water for Brewing Beer

If you’re stuck on the best water to use for brewing beer, the biggest improvement comes from understanding what you’re starting with and keeping your process consistent.

Whether you’re using tap water, bottled water or brewing with reverse osmosis water, each approach can produce excellent beer when used properly. The key difference is how much control you want over mineral content and how much time you’re willing to spend adjusting your water.

For most homebrewers, the biggest gains come from getting the basics right: using good-quality water, removing chlorine where needed, and brewing consistently batch to batch. Once you’ve got a feel for your water, it becomes another tool you can use to shape your beer, rather than something to worry about on brew day.