Create Your Own pH Probe Storage Solution

pH probes should be stored in a potassium chloride (KCl) solution to maintain the probe's internal chemistry. It is easy to create your own storage solution if you have the right stuff.

An ideal start to your storage solution is to start with a bottle of pH 4.0 calibration solution. Expired solution is perfect. If you don't have that, an alternative would be to use distilled water as the starting point for your storage solution.

All you need to do is add the proper amount of potassium chloride to the calibration solution or DI water to create your storage solution. It turns out that there is variation in the recommendations of what KCl concentration pH storage solutions should have. Recommendations range from 1M to 3M. That M means moles per liter. So to create a suitable storage solution, you need to add between 75 and 223 grams of solid KCl per liter of your fluid (this creates the 1M to 3M concentration). Yes, that much solid will dissolve in the liquid, it just might take a day or two.

Potassium chloride is a common mineral and can be found in local retail outlets. If you can find water softener supplies, potassium chloride is often available as an alternative to sodium chloride. Just a few chunks of that stuff should make up enough storage solution for a lifetime. Another alternative is to go to the salt aisle at the market and get some "Salt Substitute". Morton is a common brand. While there are other substances in the salt substitute products, it appears that the impurities are less than about 3 percent and they probably won't adversely affect the intended use.

The final component is adding a Benzoate preservative to the solution to help reduce biologic growths in the solution. Either potassium benzoate or sodium benzoate can be added. Use the manufacturer's recommendation for dosing that preservative to the solution. I haven't done this, but probably should.

So, you can see that storage solution is easy to create.

Enjoy!

Is the sulfate/chloride ratio important?

Some brewers rely on the sulfate/chloride ratio too much when gauging their mineral additions and their effect on beer flavor. The over reliance on that ratio by brewers is what drives me to caution against it's use. The sulfate/chloride ratio (or vice versa) is discussed in several well known texts that I know of. These include: Malting and Brewing Science and Handbook of Brewing. So the commercial brewing community has long known of that ratio.

The problem with the ratio is that it's effect on flavor is only properly reflected when the concentrations of those ions are modest. When the concentrations are very low, they aren't apparent enough in the beer taste to make a difference to the drinker. When those ion concentrations are high, they may overwhelm the beer flavor.

I coined a criterion that helps define when the sulfate/chloride ratio is likely to be useful and descriptive:

When the chloride concentration falls between about 25 and 100 ppm, the ratio can have a degree of validity.

The other problem I have with the ratio is its popular premise that it affects Maltiness or Bitterness. I dislike those descriptors. I feel the more accurate descriptors are: Fullness or Dryness. This latter description is actually presented in Malting and Brewing Science. Fullness does help malt character in the beer to exhibit and conversely, Dryness allows the perception of bitterness to come through better.

Having a better understanding of the ratio and its effect on beer flavor can help a brewer better understand the consequences of their mineral additions. Don't rely solely on the ratio. Be sure to look at the total concentrations and consider the ratio more valid when the chloride concentration falls within the limits above.

Do I need to worry about adjusting RO water?

Reverse Osmosis (RO) water has gained popularity since it offers brewers a "blank slate" for their brewing. Most ions are stripped from the water. However, some brewers have found out the hard way that they still can screw up their beer using that water.

RO water doesn't enable the brewer to totally ignore water chemistry in brewing. A case in point was a brewery that John Palmer and I visited in Central Indiana in 2013. That brewery used 100% RO in their brewing with no acid or mineral additions. While that worked for a few of their beers, it was a failure for others. Their IPA was particularly substandard since it suffered from a tannic astringency due to a resulting high mashing pH. The flavor of the beer was also relatively bland due to its lack of flavor ions (Mg, Na, Cl, SO4) in the water.

Using pure RO water, a brewer might be able to mash an amber-colored grist to a proper pH without adding acids or minerals. However, a combination of treatments might be required for RO water in order to get a mash to a proper pH for most other grists. A yellow grist is going to need an external acid and/or a calcium addition to get the pH down. Darker grists might need an alkalinity addition to avoid an overly low mash pH. And in almost any beer, having too little flavor ion content can leave a beer bland or tasteless. (Overdoing flavor ions can screw beer up too!)

Even with RO water, the mash is likely to need a pH adjustment in the form of an external acid, acid malt, calcium and magnesium additions, lime, or baking soda. Achieving an appropriate mash pH is always the critical concern in brewing. Adding flavor ions is an option, but is not required. Flavor ion additions are part of the brewer's art and palate.

Sparging water is one area where the brewer CAN use RO without any additions. The naturally low alkalinity of RO water means that it can always be used for sparging without acid or mineral adjustments, if the brewer so chooses.

RO water is a great starting point for brewing liquor, but it still requires the brewer's attention and adjustment!

The Care and Feeding of Your pH Meter

Questions regarding pH meter storage and calibration come up frequently. Here are my recommendations for enhancing the longevity and performance of your meter and probe.

Below is a photo of the storage and calibration solutions I use for my meter and probe. The large bottle is an expired batch of pH 4 solution that I added potassium chloride to create a 1N KCl solution. Note that I cut a hole through the bottle cap so that the probe can be stored submerged in the solution. Potassium benzoate should also be added to the solution to help reduce biologic growth in the solution. (PS: I haven't added the benzoate and haven't noted growth...yet)

The other bottles in the photo contain pH 4 and 7 calibration solutions. Since those calibration solutions have a finite life (typically less than a year), it is important to replace them on a regular basis. To reduce the cost of replacement, I recommend using dry buffers such as the pHydrion products shown. There are multiple capsules of dry buffer in the small containers. You add the contents of one capsule to 100 mL of distilled water to create a fresh buffer solution that will last for about a year. Keep each solution in a small sealed container such as those shown below.

For calibration, I pour a cap full of each solution and submerge the probe in each. Be sure to rinse and dry the probe before submerging in either solution. (I use RO water to rinse and then blow excess water off the probe with my mouth and never touch the bulb). Be sure to take your time when calibrating. The meter and probe reading will vary and its best to leave the probe in each solution for several minutes before accepting the reading. Do not return the used solution from the cap to the bottle. Throw it out.

These are economical ways to keep your probe performing well and your meter calibrated.

Enjoy!

Wort pH and its Effect on Hops and Bittering

A listener to my recent BrewStrong interview asked about why malty beers tend to be better when the wort pH is around 5.2 and hoppy beers tend to be better when the wort pH is around 5.4.

That recommendation for higher pH for the hoppy beers and lower pH for malty beers comes from Colin Kaminsky and AJ DeLange, my colleagues for the Water Book.

It makes sense when you think about it for a moment. Its pretty well known that hops contribute alpha ACIDS to the wort. When you lower the wort pH, you reduce the chemical "incentive" for those alpha acids to be extracted into the wort. This is in part because the wort acts as a Conjugate Base with respect to the alpha acids. The more basic the wort pH, the more likely the alpha acids will be extracted and reacted into the wort.

This effect can be quickly exhibited if you allow the wort pH to rise well above the desirable pH limit of around 5.6. Then the hops and their flavor in beer can become rough or coarse. Likewise when brewing a malty beer, a low wort pH helps reduce the extraction of bittering and other rough flavors from the hop plant materials.

So when aiming for a certain hopping and bittering character in your beer, recognize that wort pH has an important effect.

Do you calculate mineral additions based on the total water volume used or the final batch volume?

You treat your water based on the total pre-boil volumes. As long as you aren't boiling the crap out of the wort and loosing more than about a gallon per hour, the effect of the mineral additions is correct when they are calculated on the total water volume used in your brewing.

Think about this: In the days before brewers understood that they could alter their local water with mineral additions, they used the mineral content they had and they boiled the wort down as desired. They didn't somehow alter their mineral content to fit the final wort volume.

What is the difference between alkalinity and pH?

Alkalinity and pH are only vaguely related by their interaction. However, they are not the same thing. Here is a quick summary:

Alkalinity is a measure of the buffering power of water. In the vast majority of cases, alkalinity is comprised of carbonate ion species (bicarbonate and carbonate) in drinking water. The pH of the water affects how much of each of those species is present. In drinking water, alkalinity is the derived from the concentrations of the bicarbonate and carbonate ions in the water.

pH is a measure of the hydrogen ion concentration in water. Since the hydrogen ion concentration is very, very low, chemists use the pH designation to give it a more usable form. For instance, pH 7 is equal to 0.0000001 moles of hydrogen ion per liter of water. Pretty clunky, yes? So pH 7 is a lot cleaner way of expressing that teeny concentration.

So, you should be more able to understand that alkalinity is based on the concentration of those carbonate species and pH is based on the concentration of hydrogen ions.

Pale Ale Brewing

Many brewers have found that they just can't produce that "Pop" in their hoppy brews that they sometimes find in commercial hoppy beers like pale ales. Water chemistry is critical to these hoppy styles.

The availability of inexpensive reverse osmosis water may contribute to this problem. For pale ales and IPA's, low water mineralization can tend to leave the beer somewhat flavorless. In addition, if some form of acid is not added to the mash, the mash pH is likely to be too high and the opportunity to extract tannins rises. John Palmer and I visited a brewery that used straight RO water with no minerals. Their IPA had the problems mentioned above.

The Pale Ale profile in Bru'n Water has proven to be a compliment to typical pale ale and IPA brewing. This profile is a compilation of water profiles devised by notables such as Mosher and McDole. As outlined in the Zymurgy article on Burton water conditions, it turns out that this pale ale profile with its modest (compared to Burton water) mineralization is more likely to be what Burton brewers used to craft their beers. The dilution of their groundwater with the River Trent water made the difference. Their pure groundwater was too minerally to make good beer.

While the dryness provided by the 300ppm sulfate content of the Pale Ale profile can be pleasing, some drinkers may prefer a less dry character in their beer. Experience suggests that a 100 ppm sulfate content is the lowest that might be considered suitable for pales and IPAs. 200 ppm may be a good starting point for many brewers.

Be aware that when you add a bunch of gypsum to low alkalinity water like RO, it is likely that you will HAVE to add some alkalinity to the mashing water to keep the mash pH from dropping too low. For hoppy beers, targeting a mash pH of 5.4 does improve the hop expression. If the pH is much lower than that, the expression WILL suffer.

How to Handle Variable Water Quality

It is difficult to brew with consistency when the quality of your water supply varies. Shifting hardness, alkalinity, and mineral content can make you pull your hair out! Here are some things a brewer can do to help evaluate and correct for a varying water supply. All the following information assumes you have a water report from some point in time for your supply.

The most important factors for brewing water are Hardness and Alkalinity. They are important in establishing the mash pH. Fortunately, there are simple test kits that can be used to establish what your current hardness and alkalinity values are. These kits are widely used in aquarium and water treatment industries. Suppliers such as Hach and Lamotte provide high-quality kits to the water treatment industry and suppliers such as Salifert provide test kits for the aquarium industry that are nearly as precise.

Hardness is contributed by mainly calcium and magnesium in most potable water. Typically, you can obtain hardness test kits that report either Total Hardness, Calcium Hardness, or Magnesium Hardness. If you know that magnesium is typically very low in your water, you may be able to skip testing for Mg. However in most cases, you will need to determine the magnesium and calcium content.

Note that Total Hardness is generally equal to Calcium Hardness plus the Magnesium Hardness. So knowing two of the results will enable you to calculate the other.

With Calcium and Magnesium Hardness values typically reported in “as CaCO3”, grains per gallon, or degrees Hardness values, they need to be converted to true ion concentrations using the calculators on the Water Report Input page of Bru’n Water. Use these new Ca and Mg concentrations as the inputs for your “current” water report.

Alkalinity test kits provide the current condition for your water. Often, those kits report their results in “as CaCO3”, degrees Hardness, or milliequivalents/Liter units. Convert those values to a Bicarbonate (HCO3) ion concentration using the calculators in Bru’n Water for use in the Water Report Input.

With current Ca, Mg, and HCO3 concentrations, you are much more likely to produce the mash pH you target and be able to acidify your sparging water down to a desired low alkalinity. These are the most important things you can do for your brewing.

The final piece of the puzzle is not easily determined: figuring out how the Flavor Ion (Na, SO4, Cl) concentrations have changed as your water source varies. Testing for those ions is not as easy as hardness and alkalinity and testing kits for those ions can be much more expensive. An acceptable work-around is to assess the Total Dissolved Solids of your water using a relatively inexpensive TDS meter. Measuring the current TDS and comparing it with the TDS value calculated in Bru’n Water for the “current” water report that you have created, allows you to proportionally increase or decrease the flavor ion concentrations to bring the calculated TDS closer to the measured value. Although this approach is not highly accurate, it does better account for the current water quality. Please note that the TDS calculation is only available in the Supporter’s version of Bru’n Water.

So, a few inexpensive test kits and a TDS meter can help you bridge your variable water quality and improve the consistency of your beers.

Enjoy!

When to Add Water Additives?

When should you be adding minerals and acids when brewing? Common choices include adding them directly to the mash or to add them to the water prior to adding grain. Here are reasons that they should be added to the water prior to adding the grain.

An important reason is that 'sometimes we just screw things up'. Say you add too much of a mineral or acid? It is much less costly to dump a pot of water than a tun full of mash. Adding the minerals and acids to the water is a kind of a safety factor in case of screw ups!

Another consideration is that by adding those additions to the water first, you can verify that they have dissolved fully and that they are fully distributed in the water by mixing. If minerals and acids are added to the mash, it is more difficult to insure that those components are fully distributed through the mash. It takes a lot of mash mixing to make sure those constituents are well distributed.

An exception is when lime needs to be added to the mash to avoid an overly low mash pH. Adding a dose of lime to water can cause the existing calcium to drop out of the water. Fortunately in the cases when additional alkalinity is needed, there probably isn't much calcium or bicarbonate in that water and the lime addition won't cause additional calcium to drop out. So it's probably not imperative that lime be added only to the mash and not to the water first. So if your water has low Temporary Hardness (aka: low calcium and bicarbonate), then it is not imperative to add lime only to the mash. It is OK to add it directly to the water then!

Add minerals and acids to the water prior to doughing in the grain.