Many craft beer purists will scoff at the idea of a hard seltzer, but it is undeniably one of the most popular offerings in local, regional, and national breweries. When done right, it is dry, crisp, and refreshing. You can back-sweeten it, or have it plain. Both of these techniques are discussed below.
Hard Seltzer Ingredients
There are only a handful of ingredients that you need to make a good hard seltzer. We separate these into two categories – what you need to make the neutral base, and what you need to add the flavoring.
For the base, all you need is the following:
- Water (If using distilled or RO water, you will also need some salts)
- Phosphoric/Lactic Acid
- Yeast Nutrients
For your water, you shouldn’t need to make too many adjustments. We always recommend knowing what your water profile is, so if you do not, you may want to consider performing a water analysis through a company such as Ward Labs. If you are using a municipal water source, make sure to use a product with sodium metabisulfite or potassium metabisulfite such as Campden tablets to remove the chlorine. Unlike beer brewing water, you do not need to optimize sodium, sulfates, chloride, or bicarbonate to promote body, sweetness, or anything like that. You do want at least 50 ppm, but no more than 150 ppm, of calcium for taste and to lower the pH. Just make sure none of the other ions are too crazy. I would keep sodium and bicarbonates as low as possible (below 5 ppm for sodium and 50 ppm of bicarbonates), and sulfates and chlorides below 100 ppm.
The sugar should be either cane sugar or beet sugar. You can add in some corn sugar, but we have found that 100% cane sugar works fine. For a 4.0% ABV base, you should use about 11 oz of sugar per gallon. You can always add slightly more or less sugar and take a quick gravity reading to adjust the ABV. Since you will not be boiling the sugar water for more than 15 minutes, the gravity will not change much between pre-boil and post-boil.
Because you do not have the enzymes in the malt to lower the pH to the low 5’s, you may need to add a small amount of phosphoric or lactic acid instead. A pH in the low 5’s is essential for brewer’s yeast health. The optimal pH for wine yeast is around 3.8. There is no buffering capacity without the malts, so add very little amounts of acid at a time.
Yeast choice is up to you, but we recommend using a strain that ferments quickly, is highly attenuative, and is very neutral. You do not want a strain that produces a large number of fruity esters or notes of spice. You can use brewer’s yeast, wine yeast, or distiller’s yeast. We would recommend pitching around 20% more yeast for your hard seltzer fermentation than for ale fermentation.
This is the stage that will make or break your seltzer fermentation. You do not have any of the essential yeast nutrients found in the malts, so you need to add them. You need around 300 ppm of free amino nitrogen (FAN) for healthy fermentation. Whatever yeast nutrient you currently use should work. In addition to this, we also recommend adding diammonium phosphate (DAP). You do not want to add any more than 3/4 grams per gallon of hard seltzer, or the yeast may experience overstimulation. Check your yeast nutrient to see if they use DAP and adjust your dosing accordingly. When adding the nutrients, we recommend multiple doses – once with the yeast pitch, one the following day, and another one 2 days later. You can adjust the dosing based on the fermentation of your hard seltzer. If it slows down well before you approach 1.000, add another dose. If it is actively fermenting after the first two doses, feel free to hold off on the third dose until it slows down.
The flavoring is much more straightforward than brewing the neutral base. For the flavoring you need:
- Potassium Sorbate (If back sweetening and not pasteurizing)
The flavoring can be anything you would like. The most popular flavors are tropical citrus. We recommend using the company Amoretti. They have a number of very high-quality purees and beverage infusions that you can add. If added to the brite tank/keg, flavorings are typically added at a rate of 0.8 – 2.5 mL/L. What we like to do, however, is brew the neutral base, keg it, and then add the flavorings directly to the glass. This allows us to adjust the concentration depending on our mood, and use many more flavors than just one in the keg. If flavoring this way, you do not need to use potassium sorbate or a back sweetener.
If you prefer to mix the flavorings in the kegs, you will want to add the potassium sorbate with the flavoring to prevent the yeast from fermenting out the sugar that is added. If you are pasteurizing your hard seltzer, you will not need to add the potassium sorbate.
Hard Seltzer Recipe
Compared to beer brewing, the process to make a hard seltzer is much easier. Our 5-gallon recipe is below.
- 5.5 gallons of water
- Calcium Chloride & Gypsum
- 3.78 pounds of domino sugar
- Phosphoric Acid
- 2 Homebrew Pouches of White Labs California Ale Yeast – WLP001
- 1 Gram of Yeast Nutrient & 0.75 Grams of DAP (With Yeast Pitch)
- 1 Gram of Yeast Nutrient & 0.75 Grams of DAP (1 Day After Yeast Pitch)
- 1 Gram of Yeast Nutrient (Day 4 of Fermentation)
- 40 mL Isinglass
- Pineapple Beverage Infusion from Amoretti
- 2.5 tsp of Potassium Sorbate if Adding Flavoring to Brite Tank
First, fill up your boil kettle with 5.5 gallons of water. I did not list out an amount of calcium chloride, gypsum, or phosphoric acid because that will depend entirely on your water composition. Add Calcium Chloride & Gypsum, if necessary to get a water profile of about:
- Calcium – 75 ppm
- Sodium – 0-5 ppm
- Sulfate – 50 ppm
- Chloride – 50 ppm
- Bicarbonate – 0-35 ppm
Once you add your salts, measure your pH. The salts will slightly lower the pH on their own, so make sure you still need to add acid. If you do, add very small amounts of acid, mixing after each addition. Once you get a pH of around 5 (it does not need to be exact) you are ready to move on. If you accidentally add too much acid, you can add a small amount of bicarbonates in the form of pickling lime or baking soda to bring it back up.
Stir in your sugar without the flame on. Adding sugar with a flame can cause the sugar to carmelize and add flavors you do not want. Once your sugar is added, measure your gravity. It should be right around 1.030. Do not be alarmed by the low gravity as it will ferment all the way to 1.000. If you need to adjust the gravity, now is the time to add a little more sugar. Once you are satisfied with the water profile, pH, and gravity, start heating the mixture up to a boil. The boil is much shorter than it is for beer. You do not need to isomerize any hops, develop any color, stabilize the wort, etc. The only goal of the boil with the hard seltzer is pasteurization. Because of this, you only need to boil the sugar solution for 5-10 minutes. Once you complete your boil, move on to knockout.
During knockout, rapidly drop the temperature to around 64 degrees and make sure to add plenty of oxygen. We want to do everything we can to make sure the yeast is as happy as possible. Once you have everything transferred to your fermenter, it is time to pitch the yeast and yeast nutrients.
Measure your gravity and pitch your yeast. It should be very close to the pre-boil gravity. In a sanitized container, pull off a sample of the boiled sugar water, and with a sanitized stirrer, mix in the yeast nutrient and DAP. Once well mixed, pour the nutrient and DAP mix into the fermenter. Add the rest of the nutrients as needed. Ferment the hard seltzer at 67 degrees until it reaches a gravity of 1.000. Once it reaches 1.000, cold crash your fermenter for at least 3 days to draw as much sediment and trub to the bottom of the fermenter as you can. After the cold crash, transfer your hard seltzer to the brite tank to carbonate. We would recommend using a clarifier such as Nalco or isinglass when transferring to the brite tank. Also, if you have a filter, there is no better product to use it on than a hard seltzer.
Conditioning and Packaging
If adding flavoring to the brite tank, add your flavoring and potassium sorbate mixture to your sanitized brite tank before adding the hard seltzer. If you are adding the flavoring to the glass as we do, or are planning on having it plain, you can simply transfer the hard seltzer like normal. Once the hard seltzer is transferred, hook up CO2 to your carbonation stone (connect to the out post if using a soda keg), set the regulator to about 4 psi, and with the lid off, allow the CO2 to scrub the solution. This will remove the volatile aroma compounds leftover from the yeast such as sulfur and DMS. Let this run for 5 minutes. Once the scrubbing is complete, carbonate your hard seltzer to 3.00 vols of CO2, keg it, and enjoy!
If you try this hard seltzer, or a recipe like it, feel free to leave us a comment below! And please don’t hesitate to reach out with any questions. If you would like exclusive brewing content, sign up for our newsletter below. Cheers!