Search for "does cold brew break a fast" and you will find a wall of confident answers. Most of them are written by brands that want you to buy the drink. So here is a different approach: the exact numbers on our can, what they do and do not tell you, and a short method for reading any canned coffee label before it goes into a fasting window. We are not making a call on your protocol. You are.
Founder's Take
I am the founder of Bare Brew, and I made a deliberate choice with this page. The easy move for a coffee brand is to put "fasting friendly" in the title and let people assume. I would rather be accurate. Our can says 20 calories. For some people who fast, 20 calories is irrelevant. For others, it is a line they will not cross. I do not know which group you are in, and I am not going to pretend a label can answer that for you. What I can do is make the label easy to read. If you fast for medical reasons, that decision belongs with your doctor, not with a coffee company.
What is on the Bare Brew label
Here is the full nutrition and ingredient picture for one 12 fl oz can, as printed on the can:
- Ingredients (2): Honduran Arabica cold brew coffee and water.
- Sugar: 0g.
- Calories: 20. Not zero. We call it low calorie, never calorie-free.
- Total carbohydrate: 5g. Not 0g.
- Caffeine: 320mg.
- Sodium: 15mg. Potassium: 350mg.
The headline number for most people reading this is the 0g of sugar. That part is simple: no added sugar, so no sugar spike from the can itself. The part that needs your judgment is the 20 calories and the 5g of carbohydrate. Those come from the coffee, and we have not added anything to get there. But they are real, and they are on the label.
Why "does it break a fast" has no single answer
There is no universally agreed rule for what counts as breaking a fast. Some people define a fast strictly: water only, nothing else. Others allow black coffee or tea. Others work with a calorie allowance, and the number varies from person to person. Protocols such as 16:8, 18:6 and OMAD each get described differently depending on who you ask, and the reasons people fast (habit, preference, religion, medical supervision) change the answer again.
That is why a flat yes or no from a brand should make you suspicious. If a post tells you cold brew is "perfect" for fasting, ask what protocol the author had in mind, and whether they sell cold brew. We sell cold brew. That is the disclosure.
A three-step method for reading any canned coffee label
This works for our can and for anyone else's. It takes about thirty seconds.
- Read the ingredient list first, not the front of the can. A short list means fewer variables. If you see milk, cream, sweeteners, flavors or gums, the nutrition panel will change with them. Ours has two ingredients, so there is little to decode.
- Check calories and total carbohydrate together. A label can say "zero sugar" and still carry calories from milk, creamers or sweeteners that are not sugar. Look at the calorie line and the total carbohydrate line, not just the sugar line.
- Decide against your own rule, written down before you shop. If your rule is "nothing but water," no canned coffee passes. If your rule is "under a certain calorie number," compare the label to that number. Do not let the packaging set your rule.
If you want a deeper comparison of what is on other canned coffee labels, our guide to the cleanest cold brew and our roundup of the best canned cold brew go brand by brand. Our zero sugar cold brew guide explains how to check that a "zero sugar" claim holds up.
Where Bare Brew is a weaker fit, and what it costs
A good label post should include the parts that do not flatter the product. A few of them:
- It has calories. If your fast excludes anything with calories, this is not your drink. Plain hot or iced black coffee that you brew yourself, or plain water, sit differently on that rule. We would rather you know that now.
- Caffeine is high. At 320mg per can, one can is a large dose. Caffeine tolerance varies a lot between people, and it is worth reading our cold brew caffeine guide before you plan around it. If you are sensitive to caffeine, pregnant, or on any medication, ask your doctor or prescriber first.
- It is not the cheapest caffeine. A single can is $6.00 ($23.99 for a 4-pack, $4.50 per can on the 12-pack at $53.99). Shipping is a flat $8.99 on every order within the US, with no minimum and no free-shipping threshold. If cost per milligram of caffeine is your priority, Celsius is cheaper. Our label-transcribed caffeine data for 18 products shows the comparison.
What the research says about coffee, in general terms
This section is about coffee and caffeine in general, not about our product. Caffeine is among the most widely studied compounds in nutrition research, and studies commonly report effects on alertness. Those effects differ from person to person, depending on tolerance, genetics, body weight, sleep and medication use. Studies of this kind show associations, not guarantees, and nothing here is a promise about how you will feel. Bare Brew is a coffee, not a supplement, and we make no claim that it treats, prevents or improves any condition.
On acidity, one peer-reviewed comparison is worth knowing. A study published in Scientific Reports (Rao and Fuller, 2018, doi 10.1038/s41598-018-34392-w) found cold brew has a lower total titratable acidity than hot brew at a comparable pH. That is the extent of what we cite. There is no sourced percentage, which is why we wrote a whole post taking apart the popular number: Is Cold Brew Less Acidic? The 67% Claim vs. the Data. If you have a digestive condition, talk to your doctor.
If blood sugar is the reason you are looking at labels, our post on coffee and blood sugar covers what the research does and does not say. We keep the product out of that conversation on purpose.
Nitro, lattes and flavored cold brew
Nitrogen infusion changes texture, not what the ingredient list says, so the same label-reading method applies. The bigger variable is anything added to the coffee: sweet cream, syrups, milk alternatives. Those change calories, carbohydrate and sugar, sometimes a lot. Read the panel for the exact product in your hand. Do not assume one "cold brew" label looks like another.
Frequently asked questions
Does cold brew break a fast?
It depends on how you define your fast. Black cold brew with no additives is low in calories, and Bare Brew is 20 calories with 0g sugar per 12 fl oz can. Whether that fits your protocol is your call, and a doctor's call if you fast for medical reasons. We do not claim it does or does not break a fast.
Is Bare Brew zero calorie?
No. It is 20 calories per can and 5g of total carbohydrate. It has 0g of sugar.
What is in Bare Brew?
Two ingredients: Honduran Arabica cold brew coffee and water.
How much caffeine is in a can?
320mg per 12 fl oz can.
Keep reading
- Is Cold Brew Healthy?
- The Cleanest Cold Brew Coffee
- Best Canned Cold Brew Coffee 2026
- Coffee and Blood Sugar: What the Research Actually Says
- Bare Brew: Newsweek Readers' Choice Finalist (We Did Not Win)
Disclosure: Bare Brew is our own product. This post is general information, not medical advice. If you are fasting for medical reasons or take prescription medication, ask your doctor or prescriber.
