VinePair is ringing in the Holiday Cheers with a spotlight on the bottles we’re gifting (and hoping to receive) and a look inside some of our favorite holiday traditions and recipes — from elevated Eggnog to all things bubbly. Plus, we’ll be reflecting on the past year in the beverage industry and shifting our focus to the drinks trends we expect to see in 2022.
‘Tis the season to raise a glass of something festive and celebrate with friends. If there’s one season that is ruled by golden coupes of Champagne, it’s the last two weeks of the year. But beer shouldn’t be forgotten in all the fun.
In fact, as a brewer there’s nothing quite like popping a 750-milliliter bottle of homebrew that sparkles just like sparkling wine to share with (and of course, impress) your loved ones.
There’s a simple tool available to brewers to give beer that light body and ultra-dry finish to rival the best Champagnes pouring at the New Year’s Eve fete.
Here’s some advice from pros and homebrewers who have been there about using enzymes (specifically glucoamylase) to make the ultimate bottle of homebrewed bubbly.
What Is a Dry Finish?
First, it would be good to note what makes a beer dry and why it matters. “Dryness” in wine, beer, and even vermouths refers to the amount of residual sugar and carbohydrates left in the liquid when it is ready to serve.
In beer we measure this as specific gravity or SG (usually using a hydrometer but a refractometer also works) a unitless scale that expresses the density of wort or beer as a ratio to the density of water. The SG of water is 1.000 while the SG of wort will start out in the 1.060 to 1.030 range and most finished beers will have an SG of roughly 1.010 to 1.020. This finished beer SG is referred to as the final gravity (FG).
Brut and even extra brut Champagnes are back sweetened with sugar during dosage, but even with back sweetening they still have an FG around 1.003, and Champagnes made with no dosage in the brut nature style end up with an FG less than dense water, around 0.995.
That lack of sugar on the palate allows the spritz of sparkling wine to feel extra lively and keeps the finish clean, giving an overall light and bubbly quality that sets the tone for a celebration.
To get homebrew down to those numbers, it needs a little help and careful recipe planning.
What is the Enzyme?
Glucoamylase (referred to interchangeably as amyloglucosidase) is an enzyme that does exactly what natural enzymes already in the mash from malt do: break starches down into fermentable sugars. Glucoamylase is special because it is able to produce highly fermentable glucose units from starch, dextrins, and maltose that other amylases can’t break down.
This ability to break down more starches and carbohydrates is what brings down the all-important FG number.
“You don’t necessarily have to add the enzyme itself,” says Fowler, because you can use a yeast strain that naturally produces glucoamylase. These yeast strains are known as “STA-1 positive” strains or “diastaticus strains,” a mutated version of typical brewers yeast.
Most diastaticus strains are very characterful and naturally produce fermentation flavors ranging from spicy pepper and clove like phenols, to fruity banana and pear esters. They tend to be Belgian strains and saison strains known for creating dry and yeast-forward beers.
If a brewer wants to make a super-dry beer without so much yeast flavor, that’s when it’s time to turn to adding the enzyme. There are several products for homebrewers that provide a pure dose of enzyme; just make sure to check the label for dosing rates.
Using this enzyme with a clean yeast strain like American ale yeast or lager yeast leaves an almost completely blank flavor canvas to build on because while glucoamylase is busting through starches and dextrins; it’s also destroying the malt flavor along with them.
This was essential to the brief heyday of the brut IPA style. “The idea of the beer was to have a base profile which was crisp/clean and had low malt characteristics. This would allow us to really let the hops shine through in unique ways,” says James Conery, innovation manager at Sierra Nevada Brewing Co.
Erik Fowler, education and brewery experience manager at White Labs, says the White Labs glucoamylase product Ultra Ferm also enjoyed a short spike in popularity among homebrewers, but mostly the enzyme is used in the most flavorless beer style of them all: the American light lager.
Commercial brewers love glucoamylase because along with removing body and flavor it also neutralizes calories and carbohydrates by getting the sugar down to zero.
“This enzyme was originally used in so-called diabetic beers,” Fowler says, “which were marketed to health-conscious consumers.”
When to Add the Enzyme?
Glucoamylase can be added at two times during the brewing process: in the mash or during fermentation. There are benefits and drawbacks for each.
Popular homebrewing blog Brülosophy did an experiment comparing a brut IPA made with enzyme in the mash to one made with enzyme in the fermenter. The results were that the beer made with enzyme in the fermenter was clearer, had less malt flavor, and had more perceived dryness.
Fowler says this is because the enzyme denatures at normal mash temperatures (it is most active at 131-144 Fahrenheit (55-62 C) and denatures completely at 149 Fahrenheit (65 C), so the enzyme doesn’t have as long to work on starches and dextrins as it does in the fermenter.
Naturally, this would mean it makes sense to add it to the fermenter, but there is one consideration with that method. “The only concern would be reusing yeast,” says Fowler. “When harvesting you will have a minimal amount of the enzyme that’s carrying over [to your next batch].”
If a brewer isn’t planning to repitch the yeast in a batch, Conery has advice for optimum enzyme performance. “I would add it to the mash and the fermenter to drive the conversion as far as possible,” he says.
Fermentation may take longer with batches using an enzyme. Once yeast activity dies down (you don’t see bubbles in the airlock or blowoff) check your SG every day or so until the reading is at or below 1.000.
Putting the Sparkle in the Bottle
After the work to get the final gravity down to 1.000 or lower is done, there is still another step to making a Champagne-like beer because even the driest beer can’t fill the role of a glass of bubbly without plenty of… bubbles.
When carbonating these beers shoot for a carbonation level above 3.0 volumes of C02 (vols CO2) — ideally above 3.5 volumes. After all, the average bottle of Champagne is carbonated to 4 vols CO2 but can go higher, all the way up to 6 volumes. Knowing that fact, those big, heavy-bottomed Champagne bottles start to make more sense.
Check the level of CO2 your homebrew bottles can hold. Standard 12-ounce homebrew bottles are rated for 3.0 vols CO2. There are slightly upgraded “Belgian” 12-ounce bottles that are rated for 3.5 vols CO2 and then, of course, you can spring for the larger 375-milliliter or 750-milliliter bottles that can contain 4 or more volumes. (This guide from Northern Brewer is a good reference when selecting bottles.)
Cheers to a New Year and a new tool in your arsenal for making beer fit for even the most fabulous festivities.