Adjusting Flavor Using Brewing Salts
The Beer Judge Certification Program (BJCP) training material outlines a sensory training process for brewers and clubs using ingredients found around the home or the brewery. As Education Chair for the Aurora City Brew Club in Aurora, Colorado, I’ve expanded this test to include other flavors and particularly, solutions of brewing salts. In the past, as recommended in the training material, I’ve done the training using very neutrally flavored beers, generally a rather popular Colorado American light lager.
Using easily sourced ingredients and a neutral beer allows trainees to taste off flavors in a more interactive way than standard off-flavor test kits. For example, if the taster can’t taste the nutty flavor added by one drop of almond extract, he or she can add more until they taste the “nuttiness,” then back off until they discover their taste threshold for the flavor. On a recent Learn to Brew day I was asked to give the demonstration at our local homebrew shop, the Brew Hut, using the homemade sensory training kit I’d developed. Given the Brew Hut’s licensing restrictions, I could not bring outside beer into the tasting room and instead was provided a very flavorful, American blonde ale for use in testing. This happy accident led to an epiphany in the use of brewing salts to affect beer flavor.
While fairly neutral in flavor, the golden ale had good malt flavors, restrained but perceptible esters, low but obvious bitterness and hop presence, and good balance. In other words, I used a good professionally-brewed beer with some homebrew-like qualities for the test. To our surprise, the effects of dosing the finished, carbonated beer with the solutions of brewing salts and acids had a profound effect on the beer’s flavor. My artificial butter extract and ester solutions forgotten, we spent the rest of the afternoon testing the flavor effects of brewing salts in beer.
Setting Up the Tests
I don’t advise anyone to try dosing a carbonated beer with powdered salts to avoid the “Mentos” effect. Putting those tiny crystals in a supersaturated carbon dioxide solution (beer) may result in gushers, leaving you with a mess instead of modified beer. Instead, I prepared known strength solutions of the salts in distilled water. Since the solubility of sodium bicarbonate (baking soda) in water at room temperature is 9.6 grams per 100 mL, I use a “standard” dilution of 10% by weight. For example, if I want a 10% solution of calcium chloride, I measure out 10 grams of the salt and 90 grams of water. Exceptions are baking soda, as mentioned, at 8.8% solubility (8.8 grams of salt and 91.2 grams of water) and gypsum at 2.3% solubility (2.3 grams of salt and 97.7 grams of water).
I use the “standard” brewing salts for the test: Gypsum (calcium sulfate) and calcium chloride, as well as table salt (sodium chloride), baking soda (sodium bicarbonate), and Epsom salt (magnesium sulfate). I also test lactic acid, the standard 88% solution available at homebrew stores. I do not use chalk (calcium carbonate) because it is not soluble in water with a neutral pH. I dissolve the salts in distilled water. Stored in brown glass bottles, the solutions are essentially shelf-stable forever. Everything is food-safe and nothing in the concentrations used in testing is harmful.
Table 1 gives the percentage of each ion in the salt in the far left column. A gram of gypsum, for example, has 232 mg of calcium, 558 mg of sulfate, and 210 mg of water (note the totals may not add to exactly 1,000 mg due to rounding).
I use 10% salt solutions where possible, exceptions are baking soda and gypsum, which are less soluble in water than 10%, as mentioned earlier. Weigh the appropriate amount of salt into the container, then add water to make a combined weight of 100 g.
Table 2 gives mg of the common brewing ions per mL of solution. A few definitions and we are ready to season some beer. One part per million (ppm) is roughly equivalent to one mg per liter. If you want to add 100 ppm of an ion to a solution, you will add 100 mg per liter of solution. Another equivalency we will be using is a liter is 1,000 mL. Finally, a drop is approximately 1⁄20 of a mL.
Setting up the Tasting
The math and chemistry is not necessary for informal testing: To test the effects of the salts, I have the tasters take a sip of the 1 oz. (~30 mL) sample of control beer to provide a reference point, then add the solutions either mL or drop-wise to the beer, depending on the concentration of salt. For example, gypsum is not very soluble in water so it generally takes more of it to perceive an effect from sulfate (and it may be better to use Epsom salt to add low amounts of sulfate). I use a flavorful light beer such as helles or blonde ale for all of the salts and acid, and a roasty dark beer, something like a dry Irish stout, for the bicarbonate (baking soda), although other salts may be tested using dark beer as well. After tasting the doctored beer, I ask the tasters to tell me how the solutions changed the flavor of the beer. For a more formal test, I do a standard blind triangle test.
When I performed the triangle test using members of the Aurora City Brew Club, the test resulted in a statistically significant difference in the beers dosed with 100 ppm of sulfate from gypsum but not with bicarbonate from sodium bicarbonate. Things got interesting afterward, during homebrew tasting and bull session. A group assembled around my test solution and we began dosing peoples’ beers. Here’s a summary of the results:
• Sulfate generally was not perceived positively. Testers mentioned decreased mouthfeel and overall loss of flavor as well as increased dryness.
• Chloride performed as generally described. Testers mentioned rounder, sweeter, maltier flavors and a fuller mouthfeel compared to the base beer.
• Bicarbonate smoothed the rough edges of roasty, dark beers and made the light beer “flabby,” a loss of liveliness often mentioned in wines low in acidity.
• Adding standard 88% lactic acid improved light beers as long as the “tartness” threshold was not crossed, however it increased the harshness in other styles.
• We did not perceive any of the commonly mentioned effects from the metallic ions (calcium, sodium, magnesium). This is likely because the dosing rate kept their concentrations below taste thresholds.
Tasting process
The tasting process is as follows:
1. Pour about an ounce (30 mL) of beer into a small glass and taste.
2. Pour a second 1-oz (30-mL) sample and, with an eyedropper, add salt solution, either by drop or mL, and stir the salt solution into the beer.
3. Taste the first sample and then the second sample and describe the change.
4. If you consider the results to be an improvement and are attempting to improve a beer, calculate the amount of salt you need using the procedure described earlier.
If you’re doing this test on finished, carbonated beer, you can modify your recipe and add the required salts to the next batch at any point in the brewing process after the mash. If you’re testing at packaging, remember the carbonation will contribute acidity and tartness to the flavor of the beer. To calculate the amount of salt you will need for a complete batch based on the number of drops of solution used in a one-ounce (30-ml) sample (assuming drops for all but gypsum at 20 drops/mL) by 1.67 times your batch size in liters. Multiply by the concentration from table 2 (remembering 10% is 0.1) and add that much of the salt to your next batch after the mash.
Example:
1 drop of table salt solution in your 1-ounce (30-mL) sample was just right. To determine how much salt to add to your next 6-gallon (23-L) batch, multiply 1 drop by 1.67 (1/20 mL/drop x 33.3 samples per L) then multiply by 23 liters to arrive at 38.3 mL of your solution needed, then multiply by 0.1 to get 3.8 grams of salt added to the next brew of the beer.
Key takeaways
Key takeaways are that adding salts to finished beer can serve the same purpose as a chef’s saltshaker, adding that final touch that transforms the beer from good to great. Likewise, too much or the wrong salts can transform a beer from great to bad — think of over-salted food. The third takeaway was that finished beer acidity matters greatly. Reducing pH by adding acid can bring a brightness to a lackluster pale beer. Likewise, increasing the pH can reduce the harshness of an IPA or smooth out the roastiness of a dark beer. Specifically:
• If your malt flavor seems lost or the beer is too dry or thin-bodied, try dosing with some chloride.
• If your beer could stand a bit of dryness, add some sulfate.
• If your beer seems lifeless and flat, try adding a bit of acid.
• If your dark beer or IPA is too acrid or harsh, try adding some bicarbonate.
• A bit of plain table salt can improve many beers: Think of what bread would be like without it.
• Avoid excessive additions of any salt: Any of the ions can cause problems in too high of concentrations.
In conclusion, adjusting the salt content will not save a poorly made beer. There’s no acid or salt that will help if your recipe is off or your sanitation fails. But adjusting salt concentrations or pH can improve a well-made beer from good to great.
