Brewing Beer With Reverse Osmosis Filtered Water

Water is the most important of all the countless ingredients that go into the beer brewing process. The mix of chemicals and mineral ingredients interacts with each other and defines the style of beer it composes. Water treatment is a process more and more brewers are considering as they seek to create exciting new flavors.

Generally speaking, the local water supply determines the style of beer you can brew, for example, the highly alkaline water available in London helps to brew Dark Porter or Stout-style beers. When water treatment technology is used, brewers are not limited to brewing the type of beer best suited to the local supply, but can also brew other styles with greater control.

Of course, many different water treatment technologies exist today, and here we’ll cover reverse osmosis (RO) and how the process can help you achieve the brew you need. When using reverse osmosis technology to treat water, you need to know your goals. Reverse osmosis-treated water is naturally suitable for brewing certain beer types, such as the Czech-style Pilsner lager beer. While some desirable minerals may be removed using reverse osmosis, brewers can add these minerals at a later stage.

What Is Reverse Osmosis?

Reverse osmosis commonly referred to as RO is the process of purifying water through a semi-permeable membrane to remove unwanted contaminants and ions. In conventional osmosis, as demonstrated in a high school science class, fresh water and salt (or sugar) are separated by a semipermeable membrane through which water migrates from weak to strong solution, knowing that the water is equally salty on both sides (or sweet). The reverse osmosis units used in breweries are the process of pushing water under pressure to demineralize or deionize it.

This process removes most ions and dissolved solids, including iron, fluoride, chlorine, and greatly reduces bicarbonate. The result of the reverse osmosis process is water with a very low content of live minerals and alkalinity, almost the same quality as distilled water in most cases. You can think of RO water as a blank canvas, leaving room for creative brewers and matching flavors to their liking, making their beers into artisan products.

Why Is Tap Water Not Recommended For Brewing?

A lot of water in many large cities has chlorine and is also high in sodium, which is bad news for brewing beer. If you filter out the chlorine, it’s probably good water for hops or roasting beer. Another problem with tap water in cities is that mineral content varies from source to source, so you’re pretty much gambling every time you brew. Therefore we recommend that you purchase an RO system and use the filtered water from the RO system for brewing.

What Additives Need To Be Added To RO Water?

Some beer styles are suitable for direct use of RO water, such as Czech lager beer. Almost all beers can be brewed with 100% RO water, but some styles of beer require a few simple additions to get the best flavor. These additives are called “brewing salts,” and the most common are gypsum, calcium chloride, Epsom salts, chalk, sodium chloride, and baking soda.

• Gypsum (CaSO4 or calcium sulfate) is used in the water to bring in calcium and sulfate. It is a white powder.

• Calcium chloride (Pickle crisp or CaCl2) is used to add calcium as well as chloride. It is a white powder that is highly hygroscopic; that is, it absorbs moisture from the air easily so should be kept in small amounts in tightly sealed containers.

• Epsom salt (MgSO4 or magnesium sulfate) is used for the magnesium and sulfate contribution.

• Table salt (NaCl2 or sodium chloride) brings sodium and chloride to the water. Non-iodized salt is available in grocery stores for this purpose.

• Chalk (CaC03 or calcium carbonate) has been traditionally used in the past as a way to raise mash pH in cases where it may be needed. However, it doesn’t dissolve well without extraneous measures and is to be avoided by most brewers.

• Baking soda (NaHCO3) can be used in those rare cases where the mash pH should be raised.

What Is The Role Of Additives?

RO water effectively removes a large number of minerals and compounds, including chlorine and chloramines that destroy your beer. If you’re looking for a beer with a complex or specific flavor profile, you may want to add more minerals afterward. Now that you know which salts you need to add, let’s take a look at what they do and why you should add them to your brewing water.

• Calcium

Calcium is one of the most common hard water minerals in tap water, and it is also the main ion that determines water hardness. Calcium ions help to slightly lower pH during mashing, promote protein precipitation in boiling (thermal decomposition), enhance yeast flocculation, and help prevent beer stone formation. In addition, calcium also affects the fermentation process of beer and directly affects the clarity of the beer. Many lagers are very low in calcium, so it’s not necessary. Under normal circumstances, the calcium ion content in water can be kept at 50-100 ppm, which is also the recommended calcium ion content. You can get calcium ions by using calcium chloride or calcium sulfate (gypsum).

• Magnesium

Magnesium contributes to water hardness, it’s lower than calcium, and can give the beer a higher level (30 ppm or more) of acid/bitterness. The malt adds all the necessary magnesium to the mix, so there is generally no need to add more. Brewers often add sulfates (using Epsom salt or MgSO4) to their mixes when calcium levels are high in the water.

• Chloride

Chloride and sulfate together make up the main flavor of the beer. Chloride accentuates the fullness of the beer and enhances the sweetness of the malt. It’s typically used in the 40-100 ppm range in many beers, but in New England IPA styles, chlorides are often over 100 ppm and can go as high as 150 ppm. Chloride is usually added by calcium chloride, but table salt (sodium chloride) can also be used.

• Sulfate

Sulfate is an ion used to enhance the bitterness of hops by enhancing the dryness of the aftertaste. Sulfates are rarely found in lager beers, usually at levels below 30 ppm, especially in ales. For highly hopped beers, the required sulfate levels may be much higher, such as 150-300 ppm for IPA or West Coast APA. If 150 ppm or more of sulfate is used, then chloride levels should be below 50 ppm to avoid the formation of beer “minerals”. Sulfate comes from calcium sulfate (gypsum) or magnesium sulfate (Epsom salt).

• Sodium

The sodium content helps to accentuate the malt flavor and add texture to the beer, so it can be used in moderation (below 150ppm). You can increase the sodium and chloride content by adding salt to the mixture. But higher levels of sodium can make beer taste salty, and high sodium and sulfate levels can create a pungent bitterness. Winemakers generally agree that a reduction of 0-60 ppm is a safe bet. Also, brewers from water softeners need to be avoided, so water softeners contain high levels of sodium ions, knowing that it goes through the RO machine.

• Bicarbonates

Bicarbonate is a component of brewing water and plays an important role in water chemistry. Bicarbonate raises the pH of the mash, so it should be kept below 50 ppm for pale/light beers. Amber beers can use up to 150 ppm of bicarbonate (depending on the grain). Dark beers with roasted grains (like stouts) can easily reach 200 ppm or more because more bicarbonate is needed to balance out the acidity of the dark roasted malt. Therefore, there is no ideal range in mashing water, other than that required to achieve a suitable pH for mashing. In the spray water, low bicarbonate water is required to avoid extracting tannins from the grain. Therefore, even when making Stout, it is ideal to use 100% RO water for jetting.

How Do I Know What The Recommended Mineral Content Of A Brewed Beer Is?

Start with a good brewing recipe and use good water to make a really good beer. You can tweak the recipe by adding some brewing salt to the brewing water, possibly turning a good beer into a very good or excellent beer. Starting with a good base, and adding the right amount of brewing salt, can take your brew to the next level. But adding too much brewing salt to your brewing water can be more dangerous than adding too little, so pay attention to how much you add when you start adjusting your water.

If you’re not sure where to start with water additions, a good basic “all-purpose” water profile may be perfect.   A balanced water profile like this would work well for most styles of beer:

• Calcium: 75 ppm

• Magnesium: 0-10 ppm (more or less, but under 25 ppm)

• Sodium: 0-50 ppm

• Sulfate: 50-70

• Chloride: 50-70

How Can I Increase The Levels Of These Minerals?

To achieve the desired mineral level, you can add brewing salt. Most brewing salts are readily available online and sometimes in stores. These salts include calcium chloride, chalk, sodium chloride, baking soda, Epsom salts, and gypsum. Different brewing salts have different mineral properties. Calcium chloride increases calcium ions and chlorides, and Epsom salt increases magnesium and sulfate levels. Gypsum increases calcium and sulfate levels, while sodium chloride increases sodium and chloride levels. Both Chalk and baking soda can raise the pH. In rare cases, if this is a necessary step, baking soda is recommended because chalk will not dissolve without other additional reagents. Lactic acid or phosphoric acid can be used to lower the pH if desired.