How is Hard Seltzer Made? Production Process Explained

Hard seltzers have skyrocketed in popularity over the last several years, but they’re still commonly misunderstood.

If you’ve had hard seltzer, you know that it’s light, refreshing, low in calories, and bubbly. But do you know that it’s a fermented drink? As the name might imply, hard seltzers aren’t made “hard” by adding liquor. And this is good news if you’re looking for a low-alcoholic option.

Let’s look at how hard seltzers are made and how they differ from other alcoholic beverages like beer or cider. Knowing how they’re made will help you find the one that best serves your dietary needs. When it comes to poolside sippers, you want the healthiest option available.

The Origins of Hard Seltzer

The first hard seltzer was made in 1993, but they weren’t too well-received by the public — until the pandemic. There are many appeals to them, and perhaps the most overlooked is that they can be easily picked up at the grocery store, unlike canned cocktails and wine in some states.

Plus, they come in a can, making them easy to transport, fit in the fridge, and open.

Let’s look at how hard seltzers compare to beer and cider.

Hard Seltzer vs. Beer

Beer is an alcoholic beverage made from fermenting malted barley. The other three ingredients are water, yeast, and hops. Put them together, and you’ve got yourself a beer. Of course, the process is a little more complicated than that, and like hard seltzers, there is a precise science to making beer.

Here are a couple of things to know about beer:

Beers always contain gluten.
Sugar content is pretty low in most beers.
Alcoholic content in beer can range from 3% to 12%.

Hard Seltzer vs. Cider

On the other hand, ciders are alcoholic beverages made from fermenting apple juice. They tend to be lighter and fruitier, and their biggest appeal is that they are always gluten-free. However, cider typically contains more carbs and more sugar than beer.

Answering the question of which is healthiest depends on what your needs are.

Hard Seltzer Nutrition Facts

Hard seltzer is also a fermented, alcoholic beverage, but seltzers are made by fermenting cane sugar. They’re not cocktails in a can; there’s actually no liquor in them. They are their own type of alcoholic beverage.

Hard seltzers are almost always around 4% to 5% alcohol by volume. However, be sure to check the label because, occasionally, these drinks contain a higher amount of alcohol.

Hard seltzers usually contain around 100 calories and minimal carbohydrates, and most are gluten-free. The carbonation in hard seltzers makes them an excellent easy-drinking alternative to beer and wine, which can both be heavier.

Let’s break down the steps to making a hard seltzer so you can understand exactly what you’re drinking.

Hard Seltzer: The Production Process Explained

Making hard seltzers is reasonably straightforward. However, like other fermented beverages, there is an exact science to it.

Step 1: The Sugar Wash

The first step to making hard seltzer is to make the sugar wash, a blend of water and sugar. The most commonly used sugar is cane sugar (AKA sucrose), but producers can also use glucose, agave, and honey.

The other way that hard seltzer is made is with malted barley. This method is less common, especially since most hard-seltzer drinkers are looking for gluten-free options, and these kinds of seltzers are not gluten-free. Some beer producers make seltzers from malted barley. These kinds of seltzers will say “malt,” “barley malt,” or “malted barley” on the label.

Some of these sugars are easier for yeast to break down, and others require that the yeast work harder to complete fermentation, so each producer chooses what base to use depending on their desired result.

The kind of water used for the sugar wash matters, too. Distilled water or reverse-osmosis water yields the best results. Tap water has many added minerals that add a flavor that is not consistent with hard seltzers, so producers avoid using it.

Step 2: Introducing the Yeast

Yeast is arguably the most important part of fermentation.

Without the yeast, the sugar stays sugar, and the beverage won’t turn to alcohol. A neutral ale yeast strain is commonly used, but producers can also use wine yeast strains and distillers’ yeast. Different strains of yeast behave differently, so this is a choice that the producer must make.

Step 3: Fermentation

Yeast feeds on sugar and converts it to ethanol (alcohol) and CO2. This is the process of fermentation in a nutshell.

Once the process is complete, the beverage contains no sugar. Instead, it contains a certain level of alcohol — in the case of hard seltzers, typically 4% or 5%.

Fermentation typically takes 5-7 days, not long at all compared to most beer and wine. In order to initiate fermentation, the sugar wash and yeast are boiled at a temperature that is ideal for the specific yeast strain that the producer has chosen.

Too cool of a temperature could lead to the yeast having trouble fermenting or fermenting too slowly. Too much heat, however, can kill the yeast altogether. So it's vital to understand what each yeast strain requires and what its limitations are.

The biggest challenge for anyone making hard seltzer is to avoid a stuck or stalled fermentation. What this means is that the conditions aren’t supportive enough for the yeast to do its job (convert sugar into alcohol), so it becomes frozen in place, or stalled.

The resulting beverage has too much sugar and not enough alcohol. It’s every producer’s worst nightmare.

Once fermentation has properly been completed, it’s time to filter the solution.

Step 4: Filtration

After fermentation, the remaining yeast and particulate matter cause the solution to be cloudy. It also imparts aromas that the producer may not want. So, the solution is filtered. CO2 is added at this time to work out some of the aromas as well.

The result is a colorless, flavorless alcoholic liquid that acts as a blank canvas for the producers to create whatever style of seltzer they want.

Step 5: Creating the Flavor Profile

Now flavors are added.

The two most common ways to do this are adding natural flavoring extract or steeping real fruit and herbs into the liquid. Artificial flavoring is still used, but this method is falling out of favor.

Most people who drink hard seltzers are looking for healthy options to kick back and relax, and producers notice that using artificial flavors hurts their sales.

At this stage in the process, the seltzer is also pasteurized with potassium sorbate to stabilize the drink and ensure it’s safe for consumption.

Step 6: Carbonation

If CO2 escaped during fermentation, it's added back in to give that signature sparkle that makes hard seltzers so popular.

The average hard seltzer has 2.8 volumes of carbon dioxide, making it fizzier than most light beers but less fizzy than champagne.

Step 7: Packaging

Hard seltzers are easy to spot in the grocery store because they’re packaged in skinny cans. This packaging nods to the low-calorie benefits that hard seltzers provide, and it doesn’t hurt that you can pack even more of them into your cooler.

The Bottom Line? Read the Label

Now you know that hard seltzers, in all their glory, are a category of alcoholic beverages all on their own. However, they can be made in various ways with a variety of different ingredients that range in quality. If you’re looking at seltzers as a health-conscious way to have fun, peek at the labels and make sure you’re getting what you need.

The label will tell you whether or not the seltzer contains malt (which means it’s not gluten-free), how much sugar it contains, the alcoholic content, and what kinds of flavoring are added. Plus, you want to make sure you get your favorite flavors, and when it comes to seltzers, the possibilities are endless.

Looking for the perfect summer spritzer? Try Rebujito, a white wine spritz with lemon and a hint of mint. It’s made with only 110 calories and 4.5% ABV.