The most common and cheapest way to carbonate your beer is in the bottle. Instead of buying CO2, you let your yeast do all the work, and in the end you have a cold brew to drink! To make this dream a reality, you need to learn how to use priming sugar to carbonate your beer.
Priming sugar is the sugar you add to your beer before bottling to carbonate it. The yeast in the beer eat it and produce CO2, which has nowhere to go in the bottle so it dissolves into the beer. It’s cheap, simple, and produces high-quality brews.
It’s important to be very careful when using priming sugar and bottling. If you don’t add enough, the only downside is that your beer will be undercarbonated or flat. If you add too much, your bottles will overflow as you open them or even explode.
Don’t worry though! This guide will walk you through every aspect, from its definition all the way to a step by step process. You’ll be able to discuss the pros and cons of each type, and bottle perfectly every time.
What is Priming Sugar?
The yeast floating in your beer eat up all the fermentable sugars and produce ethanol and CO2. When you’re fermenting, the CO2 releases through your airlock or blowoff valve to keep the pressure low in the fermentation bucket.
When it’s time to carbonate, you can take advantage of that same process. Adding priming sugar to your batch before bottling starts the yeast fermenting again. With nowhere to release the pressure, the CO2 dissolves into the beer.
This is the most common way to carbonate when you’re bottling your homebrew. Kegging is a whole other kettle of fish. For more information on carbonating a keg of beer, check out our article on force carbonation.
Types of Priming Sugar
Most of the time, the goal of priming sugar is to provide food for the yeast without changing the flavor of the beer. However, not all sugars are fermentable, and some are mixed with other ingredients that can impart different flavors to your beer.
A lot of this choice comes down to preference. There are a lot of myths when it comes to which priming sugar to use. We’ll go over what parts are worth listening to and what parts are hogwash.
The most important part of choosing your priming sugar is careful measurement. Having too little means your beer is flat. Having too much is very dangerous. In the best case, you’ll open your beer and it will gush all over the floor. At worst, the glass bottles will explode, endangering anyone nearby and losing all your beer.
Dextrose (Corn Sugar)
Dextrose is the most popular priming sugar by far. It’s affordable, available almost everywhere, and imparts no flavors to your beer. Many brewers consider it the only option when it comes to priming sugar.
If you’re using dextrose, it’s important to note that brewers corn sugar is dextrose monohydrate. This means that a single water molecule is attached to each sugar molecule, making it 9% water by mass.
This is why you need to use 9% less sucrose than you do dextrose. Sucrose does not have that water molecule attached, so all the weight is in fermentable sugar.
Sucrose (Table Sugar)
Many people avoid sucrose, even though they have it in their homes already. The most common fear is that sucrose produces off-flavors. Some people stand by the idea that using table sugar makes your beer taste “cidery.”
However, these rumors are old wives’ tales. Everyone who has actually put this to the test has found sucrose and dextrose to taste identical. Dextrose and sucrose are equally as effective as priming sugars.
If a recipe calls for dextrose and you decide to use sucrose, you should use a little bit less sucrose. 100% of the weight of sucrose is fermentable sugar, as opposed to 91% of dextrose, so less sugar does the same job.
DME (Dry Malt Extract)
Dry malt extract is a bit different than dextrose and sucrose. It is unfermented wort dried into a powder. Because it’s a lot like adding another beer to your recipe, it can add body and flavor to a beer.
Unlike sucrose and dextrose, DME has a lot of other non-fermentable ingredients in it. The grains used aren’t always the same between DME options, either. To determine how much DME to use, you’ll need to look at the “fermentability” listed on the package. This is the amount of fermentable sugars contained in the malt.
It’s important to note that you won’t get the full fermentability listed on the package. This number on the package is measured under perfect conditions. They get the highest amount of fermentable sugars out of the grain. Your homebrew setup is likely not to use all the sugars as efficiently.
Dry malt extract is less common than the above sugars. This is due to the unpredictability of the extract itself as well as the fermenting time Because the sugars are not in their simplest forms, it takes longer for the yeast to consume them. Instead of a brew taking 1-3 weeks to prime, it may take longer.
If DME is unpredictable, honey is a complete toss-up. Unlike DME, honey is not labeled for fermentability at all. It faces the same issues with slow fermenting and estimation that DME does.
There are varieties of honey, however, that have very distinct flavors. Some brewers believe the taste is noticeable when it’s used as a priming sugar.
If you do choose to use honey, you’ll have to calculate the fermentability yourself. The easiest way to do this is to dilute one cup of honey in nine cups of water and measure its gravity with a hydrometer or refractometer.
Conditioning Tablets (Fizz Drops)
Conditioning tablets come in a package of candy-like pieces of sugar. The idea is that you can add some of these drops to each bottle, and it will carbonate every time. No calculation required! Although Fizz Drops is the brand name of a specific type of tablet, there are a variety of brands and options.
Tablets cost more because of their convenience. They will carbonate your brew well enough, as long as you aren’t looking for a specific level of carbonation. The drops can’t be broken apart easily, and using two of them would risk a bottle exploding.
This is not to say that these are useless. Due to their cost and uniformity, there are two great uses for them. The first is when you have only a few bottles’ worth of beer, so you don’t have to spend too much.
You can also use them when you have a large amount of sediment at the bottom of your bucket. Stirring in priming sugar will also mix the sediment back into your beer. If you can’t transfer your beer to another bucket, consider tablets.
Calculating Priming Sugar
You really shouldn’t calculate the amount of priming sugar you should use by hand. You could do it that way, if you really wanted to. However, the formulas are complicated, especially when you include all the variables.
Luckily, we live in modernity. This means we have digital calculators that can determine how much priming sugar we need. Homebrewers have developed a few rules of thumb for the most common priming sugars. Still, though, it’s best to plug your values into a calculator to be exact.
Exactness is vital at this stage. We recommend you weigh your sugar with a kitchen scale, in grams for the most precision. Once again, if you overcarbonate, you may end up with “bottle bombs” from the yeast creating too much CO2. You can’t be too careful on the measurement step.
Rule of Thumb
Without getting into the specifics of your own beer, there are a few rules of thumb that brewers can rely on. Although we don’t recommend using these by themselves, they can give you an idea of about how much you may need.
If you end up with 5 cups of dextrose, for example, you can tell immediately that something is wrong. All these rules assume a five-gallon batch, the average American homebrewer’s batch size.
- Dextrose: ¾ cup
- Sucrose: ⅔ cup
Although ⅔ cup is roughly 90% of ¾ cup, the actual weight of the table sugar can end up higher than the weight of the dextrose. This can depend on the fineness of the grains and how packed they are into the cup.
This discrepancy is why you should calculate this yourself. If you rely on a rule of thumb, you may be opening yourself up to a bottle bomb.
There are a few things you’ll need to know to be able to use online calculators. The first question is: how carbonated do you want your beer to be? If you’re making a breakfast stout, you may want a lower carbonation than if you’re making a dunkelweizen.
The other variable to keep in mind is temperature. This is a roundabout way of figuring out how much CO2 is already in the beer. As the yeast ferments your beer, it leaves some CO2 behind. The temperature will give you an idea of how much is already in the beer, so you don’t overcarbonate.
There are a few popular online calculators available. They are all simple to add your variables too, but each one is a bit more convenient in one way or another.
The values for every priming sugar other than dextrose and sucrose are estimates. If you choose to use one of them, it would be wise to find out the fermentability for yourself.
- Brewer’s Friend: This is the only calculator that doesn’t also offer the weight of priming sugar in grams. You either have to weigh it in ounces or convert the values. On the other hand, it is also the only calculator that includes a metric section.
- MoreBeer: MoreBeer allows you to choose a style rather than a specific volume of CO2, which is a bit more convenient. It also includes weight in grams, which is a great way to get very exact measurements.
- Northern Brewer: This very popular calculator has numbers that are slightly higher than both MoreBeer and Brewer’s Friend. However, this works out to about 0.1 volumes of CO2, which is not a large difference.
How to Add Priming Sugar
Once you siphon your beer into a bottling bucket, adding priming sugar begins. Although you can bottle straight out of the fermenter, a bottling bucket offers a few key advantages. First of all, all the sediment is left behind in the fermenter. Second of all, bottling buckets have a spigot on the bottom to make bottling quick and easy.
To make sure that the sugar dissolves evenly through your beer-in-training:
- Boil about two cups of water and dissolve your sugar in it. Boiling ensures sanitation and allows you to use less water, since you can dissolve more sugar in hot water than cold.
- Pour it into your brew and mix it in. If there is still sediment at the bottom of your bucket, this could be difficult. You have to be careful not to stir the sediment back into your beer, while also stirring the sugar into it.
That’s it! The next step is to bottle in whichever method you prefer. The amount of time you have to wait for carbonation to occur is dependent on the beer itself. A light beer may be ready in as little as a week, but this process can often take over a month.
Bottling your own beers can be a bit of a pain in a lot of ways. But there’s nothing like handing your friend a bottle with your own brew inside. If you need to transport some beers, bottling is the way to go.
Understanding priming sugar is one of the most difficult parts of bottling. Once you’ve mastered your carbonation, your beer reaches another level.
Do you have bad experiences with priming sugar? Or maybe you tried something strange and want to share? Let us know in the comments below!
Frequently Asked Questions
Do I need to add yeast for priming sugar to work?
No. No matter how long you’ve waited, there are still yeast floating around in your beer when you bottle it. The same yeast that fermented your beer will be carbonating it. There’s no need to add anything other than sugar.
Does priming sugar increase alcohol content?
This depends on a lot of factors, but the short answer is no, not considerably. The sugars convert to alcohol via fermentation. However, you’ll also be adding water, which will dilute the beer in about the same amount as the alcohol addition.
If you were adding no water with your priming sugar, the difference would amount to roughly 0.2-0.3% ABV.
Does priming sugar affect taste?
Dextrose and sucrose, or corn and table sugar, do not affect the taste at all despite any old wives’ tales about them. Any other form of priming sugar will include some amount of nonfermentable content. These may have a minor influence on your flavor. It will not be significant due to the small amount you’re adding, but it may be noticeable.