What you’ll learn in this article:
- The amount of caffeine in cold brew compared to hot coffee
- What affects the amount of caffeine in cold brew (brew time, ratio, roast level)
- How brewing equipment like Hardtank helps you control the amount of caffeine in cold brew
- Quick answers to common questions about cold brew caffeine and consistency
Hot coffee has long been the go-to for consumers looking to get their daily dose of caffeine – but cold brew is a fast-growing alternative. In the United Kingdom alone, cold brew consumption has grown by over 60% since 2021, proving how popular it has become. For drinkers looking for an energy boost, the amount of caffeine in cold brew is important to know.
Despite being made with the same kind of coffee beans as hot coffee, cold brew has very different characteristics. It’s less acidic, first of all, which typically leads to less bitter flavour notes for a smooth drinking experience. The amount of caffeine in cold brew can also vary – but by how much, and why?
To learn more about the amount of caffeine in cold brew, I spoke to Enzo Benfanti. He is the Chief Scientific Officer at Rarebird, a company developing specialty coffee with caffeine alternatives.
The amount of caffeine in cold brew vs hot coffee: How much is in each cup?
On average, the amount of caffeine in cold brew is 207mg for a 12-oz (355ml) cup. This is broadly similar to the same amount of caffeine in hot coffee, which varies from 113mg to 247mg.
Just as with hot coffee, the amount of caffeine in cold brew can vary significantly, as Enzo points out. “As with all brewing methods, it depends on the type of bean, coffee-to-water ratio, and how you dilute and flavour it afterwards,” he says.
Since traditional cold brew preparation involves a concentrate diluted into water, the ratio of water you add can impact the amount of caffeine in cold brew. “Cold brew traditionally comes in either convenient, concentrated, ready-to-pour or ready-to-drink formats,” Enzo explains. “While technically more concentrated out of the bottle, it’s up to the consumer how they prefer to dilute it.”
Once diluted, however, a typical serving of cold brew contains a similar or slightly lower amount of caffeine than the same quantity of hot coffee. The exact caffeine content varies between coffee brands, though. For example, a 16-oz serving of cold brew from Starbucks contains 205mg of caffeine. On the other hand, 16 oz of Dunkin’ Donuts cold brew contains 260 mg of caffeine. This all changes depending on how much cream, milk, or ice you add as well.
As such, it’s hard to predict how much caffeine may be in your cold brew – but regardless, it’ll be similar or slightly lower than hot coffee.
That said, using cold brew equipment with forced percolation and agitation can drastically speed up the caffeine extraction rate and ensure the highest caffeine extraction from batch to batch, while minimising batch time. Because the coffee grounds are constantly interacting with water, the extraction rate of key compounds like caffeine, lipids, and chlorogenic acid increases.
In a 2021 study, it was found that cold brew made using Hardtank equipment contained up to 18% more caffeine than hot brewed coffee and 12% more than traditional cold brew. Therefore, the method used to prepare cold brew can drastically impact its caffeine content.
Why does the amount of caffeine in cold brew vary from hot coffee?
The slightly lower caffeine content in cold brew is mostly down to its brewing method and lower extraction temperature. Using traditional methods, coffee grounds are steeped in cold water to make cold brew. However, caffeine molecules and other coffee ingredients like lipids are considerably more soluble in hot water. Therefore, if you brew for the same amount of time, the cold brew would have less caffeine and a weaker flavour.
Take this as an example: at room temperature, caffeine’s absolute solubility limit is around 2g per 100 mL of water. By comparison, at boiling temperatures (ideal for brewing hot coffee), caffeine dissolves at 67g per 100 mL.
This means that at higher temperatures, caffeine and other dissolved solids diffuse into the drink much more easily, thus having higher caffeine content and a richer flavour. To offset this difference, it’s why cold brew is traditionally steeped for much longer – usually between 12 to 24 hours.
By extending the extraction time, it gives the caffeine enough time to diffuse out of the coffee grounds at the lower temperature. If it isn’t left for long enough, though, the amount of TDS is lower and as such, so is the caffeine content and strength of flavour.
It’s also worth noting that cold brew is traditionally prepared as a concentrate. “Typical cold brew is a concentrate of one part coffee to approximately five parts water,” Enzo says. Usually, you then dilute the cold brew concentrate with water at a 2:1 ratio. Doing so, and then adding anything from syrups to milk, will reduce the concentration of caffeine in the drink, bringing it back to a level similar to hot coffee.
It’s similar to what happens at chains like Starbucks and Dunkin’ Donuts, as mentioned earlier. They will dilute the cold brew with water as is normal, and then may add ice to the cup at a customer’s request. Someone making cold brew at home with a concentrate, however, may not use the same ratio.
Therefore, the variance in caffeine content is often in the consumer’s hands. “It mainly boils down to how you make it and how much you drink,” Enzo explains. “If you brew your hot coffee with more grounds, it will taste stronger and will have more caffeine. If you put less ice or creamer in your cold brew, same thing. The best way to know for sure is by measuring your servings. When buying pre-packaged drinks, legally, they’re required to note the caffeine content.”
How Hardtank equipment helps you standardise the amount of caffeine in cold brew
As Enzo explains, cold brew with too much caffeine can have a detrimental effect on consumers. “Caffeine overconsumption can negatively impact everything from anxiety to concentration, and upset stomachs to lost sleep,” he says. “[Caffeine content] is an important education piece that cold brew companies should consider.”
For this reason, you can take a number of factors into account to control or limit the caffeine content in your cold brew coffee. However, using specialised equipment such as the Hardtank 20 is especially important because it offers you more control than manual and traditional methods.
Firstly, altering the coffee-to-water ratio of your concentrate is the best way to alter the amount of caffeine in cold brew. As Enzo mentioned earlier, the usual ratio is one part coffee to five parts water, which is then diluted further when serving the cold brew. If you alter this initial ratio of the concentrate, perhaps to one part coffee to six or seven parts water, it will reduce the caffeine content. However, it may also contribute to weaker flavour notes and aromas.
Adjusting the steeping time is another method to alter the amount of caffeine in cold brew. Usually, it is prepared overnight, though studies show that by the seven-hour mark, most of the available caffeine in the coffee grounds will be extracted. Up to this point, the longer it steeps, the more caffeine ends up in the coffee. If you want to reduce the amount of caffeine and other TDS in your drink, simply steep it for less time.
Lastly, you can also adjust the grind size. When coffee grounds are finer, they have more surface area for extraction, and as such, caffeine content. Therefore, a coarser grind will result in a lower extraction rate and less caffeine.
These methods, however, are rather imprecise. Caffeine content is difficult to measure, and even if you’re happy with one batch, it’s hard to repeat in the future. That’s why Hardtank cold brew equipment comes with built-in memory programmes. Once you’ve determined the ideal steeping time for your cold brew, you can save the recipe to ensure it’s just as consistent each time.
Therefore, Hardtank offers a solution to standardise the caffeine content in your cold brew. For higher-volume operations, the Hardtank 20 is ideal for controlling extraction. For smaller cafés, the Baby Hardtank offers similar flexibility with lower capacity. Once you’ve tested one batch’s caffeine content, such as by using TDS readings or refractometers, you can save the brewing programme to make it repeatable every time you use it.
Whether you want lower caffeine content to make your cold brew smoother or to increase it for an early-morning energy boost, you need equipment that gives you control. Then, you’ll know that your cold brew’s amount of caffeine is exactly as you intended – and as your customers want.
Want to take control of your cold brew’s caffeine content? Discover how Hardtank’s precision brewing systems let you customise, replicate, and optimise every batch: learn about our equipment range here or get a quote from the team.
FAQ
What is the amount of caffeine in cold brew?
On average, a 12-oz (355ml) cup of cold brew coffee contains around 207mg of caffeine. This is slightly lower than hot coffee, which can be as high as 247mg. With Hardtank’s forced agitation, however, cold brew can have as much and occasionally even more caffeine than hot coffee.
Why is the amount of caffeine in cold brew slightly lower?
Cold brew has a lower caffeine level due to its colder temperature during extraction. Caffeine molecules are more soluble in hot water, which means cold brew has to steep for longer to match its level. However, agitation in cold brew steeping speeds up extraction to increase the caffeine level.
Does roast level affect the amount of caffeine in cold brew?
Yes. Contrary to popular belief, light roasts often contain slightly more caffeine by weight than dark roasts, since they’re denser and less “cooked.” That said, the difference isn’t huge, and the brew ratio has a greater impact.
How can you adjust the amount of caffeine in cold brew?
To alter the amount of caffeine in your cold brew, you can adjust the extraction time, ratio of water to cold brew concentrate, and grind size.
Can I make low-caffeine cold brew?
Absolutely. You can use lower-caffeine beans (like decaf or naturally low-caffeine varieties), reduce the brew ratio, or use shorter extraction times – especially with advanced machines that allow precise control over parameters. As mentioned earlier, Rarebird also offers a decaffeinated coffee with paraxanthine, a natural caffeine alternative that offers similar energy boosts without the typical downsides of caffeine.
How can I ensure a consistent amount of caffeine in cold brew?
Using a commercial cold brew machine like the Hardtank helps ensure consistency with programmable extraction cycles and repeatable brew settings. This reduces variability between batches and gives you better control over caffeine content.
