Homemade Keto Cold Brew Coffee
Published August 4, 2019 • Updated February 26, 2026
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I make a fresh batch every week and drink it over ice every morning. This keto, sugar-free cold brew is smooth, naturally low in acid, and takes about five minutes of hands-on time.
I drink cold brew every single morning. Not sometimes, not when I remember to prep it. Every morning. I keep a batch in the fridge at all times, pour it over ice with a big splash of heavy cream, and that’s how my day starts. I’ve been making it this way for years, long before every coffee shop had a sugar-free option on the menu.
Here’s what most people get wrong: they think this is just regular iced coffee that happens to be cold. It’s not. Cold steeping extracts flavor differently. The result is smoother, naturally sweeter, and up to 67% less acidic than hot-brewed coffee poured over ice. If regular coffee bothers your stomach, switch to this.
My method is dead simple. I weigh out 85 grams of coarsely ground beans (not a volume scoop, the weight matters), add a liter of filtered water, and let it sit in the fridge for 18-24 hours. I tested different amounts over months before landing on 85g as the sweet spot for concentrate strength. Too little and it tastes watered down. Too much and it gets bitter no matter how long you steep.
What comes out is a concentrate. I dilute mine about 1:1 with water or pour it over a full glass of ice, which melts down to the right strength. Some mornings I go with heavy cream for a rich, low carb coffee that feels indulgent. Other times I blend it with ice and a little sweetener for something closer to a keto frappuccino.
The concentrate also works as a base for other drinks. I’ve used it in keto dalgona coffee, mixed it into a chocolate peanut butter smoothie for an afternoon pick-me-up, and poured it over dairy free ice cream as a quick affogato. One batch covers about a week, so I prep on Sundays and don’t think about it again until the jar is empty.
For sweeteners, I use liquid monk fruit or powdered allulose. Both dissolve in cold liquid, which matters. Granulated erythritol sinks to the bottom and just sits there. If you only have granulated sweetener, dissolve it in a tiny bit of warm water first, then stir it in.
Grind size makes or breaks this recipe. You want coarse, roughly the texture of raw sugar. Fine grounds over-extract during that long steep and turn the whole batch bitter. If you don’t have a grinder, buy pre-ground coffee labeled “coarse” or “French press grind.”
If you’re into coffee drinks, I have a whole collection worth trying: keto caramel macchiato, dalgona matcha latte, and frozen hot chocolate for when you want something completely different. Reader Amber D. said it better than I could: “No bitterness, no aftertaste, just smooth. I’ve kept a batch in the fridge every week since.” That’s exactly the result you’re going for.
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Ingredients
85 grams of freshly roasted coffee beans -
1 liter of water (about 4 cups)
Step by Step Instructions
Step by Step Instructions
Add coffee to mason jar
If using a mason jar or pitcher: Add ground coffee to the bottom of the mason jar.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
How do I order this drink at Starbucks?
I order at Starbucks all the time. Ask for a Venti, no classic syrup (they add sweetener by default), and sub in heavy cream. In the app, just customize the drink and remove all syrups. The Nitro version is also great since it's naturally creamy from the nitrogen infusion. A grande Nitro is less than 1 net carb when you drink it black.
Can I make this with a French press?
I've done it plenty of times and it works perfectly. Add your coarse grounds to the French press, pour in cold water, and put the whole thing in the fridge for 18-24 hours. When it's ready, press the plunger down slowly. The built-in mesh filter does all the work. I still prefer a dedicated brewer because cleanup is easier, but a French press makes identical concentrate.
Can I freeze the concentrate?
I freeze mine into ice cube trays whenever I make too much. The frozen cubes are perfect for iced coffee because they don't water down the drink as they melt. I also toss them into smoothies for a caffeine boost. The concentrate keeps in the fridge for two weeks, so I usually don't need to freeze it, but it's a solid backup plan.
What is the difference between this and iced coffee?
I get asked this constantly. Iced coffee is regular hot-brewed coffee poured over ice. This method steeps grounds in cold water for 18-24 hours, which extracts flavor completely differently. The result is smoother, less bitter, and significantly less acidic. I can drink this black with zero discomfort, which I never could with regular iced coffee.
Can I drink this black while intermittent fasting?
I do it during my fasting window all the time. Black, with zero calories and zero carbs, it doesn't break a fast. The smooth, less acidic flavor actually makes it easier to drink black than regular coffee. I keep a jar in the fridge specifically for fasting mornings. Once my eating window opens, I add heavy cream for a richer, low carb version.
What coffee-to-water ratio makes the best concentrate?
I use 85 grams of coarsely ground beans to 1 liter of water. I landed on that ratio after testing different amounts for months. Stronger makes it too intense even when diluted, and weaker produces something that tastes like brown water. If you want to scale up, keep the same proportion: 85g per liter. I sometimes double it when I know the week is going to be busy.
Is this less acidic than hot coffee?
Noticeably, yes. I switched for exactly this reason. Cold steeping extracts fewer of the bitter, acidic compounds that hot water pulls out of coffee grounds. My stomach handles it so much better. I've seen research claiming up to 67% less acidity, and based on how I feel after a glass versus a regular cup, I believe it.
Can I make a vanilla sweet cream version at home?
I make my own vanilla sweet cream all the time. Whisk together heavy cream, a splash of vanilla extract, and a few drops of liquid monk fruit or a tablespoon of powdered allulose. Pour the concentrate over ice and float the sweet cream on top. It layers beautifully. I keep a small jar of the cream mix in my fridge so it's ready whenever I want it.
What’s the difference between Iced Coffee and Cold brew coffee?
Cold brew is ground coffee steeped in cool water …mostly an overnight process. Iced Coffee is brewed in hot water, then cooled over ice. Because of the difference in brew methods people claim the cold brew coffee is sweeter, smoother and less bitter than iced coffee.
Although cold brew coffee can take longer to develop than drip coffee, it is completely worth the wait. Cold brew coffee is smooth almost creamy like and a little bit sweeter tasting too. You don’t get those bitter notes like you do with drip brewed coffee.
The cold brew coffee maker I use is from OvalWare, but there are many different types of cold brew coffee makers out there. Some that are automatic too.
But if you don’t want to invest in a cold brew maker, you can always use a mason jar or water pitcher. The result is basically the same. Delicious cold brew coffee.
I recommend steeping cold brew coffee for 12 to 24 hours. The longer you let the coffee steep, the stronger it will be. I’ve let the coffee brew for a little over 24 hours and it was still fine. But I love a strong cup of coffee.
When your coffee is done steeping, you will need to strain the coffee grounds. If you are using a cold brew coffee maker, you simply remove the filter containing the coffee grounds.
If you are using a jar to steep your coffee, you will need to filter out the coffee grounds through a fine-mesh sieve, coffee filter or cheesecloth. To strain the coffee, place the filter into a mesh sieve or drape the cheesecloth over the sieve. Then pour the coffee over the filter to separate the grounds from the coffee.
I'm ready to make this part of my weekly routine, how many days ahead can you brew a batch before it starts losing that smooth flavor?
About two weeks in the fridge. After that it gets kind of flat. I brew mine every Sunday so I never hit the end of the jar.
Switched from a fine grind to coarse on a whim and the bitterness I kept getting was just gone. Same 85 grams, same steep time, totally different cup. If your batch tastes sharp, try going coarser before you write off the recipe.
Fine grinds over-extract in cold water too, just slower. Same 85 grams but way more surface area, so the extraction curve is totally different by hour 20. Added a grind note to the recipe after Tricia ran into the same thing.
Smooth and completely acid-free like promised, though I wish there was a note on grind size since mine came out weak the first time until I landed on a coarser grind.
Grind size makes or breaks cold brew. Coarse is what I use, 85 grams to a liter. Adding a note to the recipe.
Just made cold brew at home for the first time and I'm annoyed at every dollar I spent on the bottled stuff. Steeped overnight in a mason jar, came out way smoother and less acidic than I expected. Does dark roast vs medium roast make much difference, or is it all about steep time?
Roast makes a bigger difference than people think. Dark gets you that chocolatey, low-brightness cup - I usually land on medium-dark. Steep time is your concentration dial, not your flavor dial.
My wife has refused to touch my morning coffee for years but poured herself a glass of this over ice this morning and said nothing, just nodded, which from her is basically a standing ovation. Something about the low acid maybe, but she's been hovering around the mason jar I keep in the fridge all week.
I thought cold brew was just gone when I went keto. Every bottled version has sugar, every coffee shop adds sweetener. Made this for the first time with 85g of freshly roasted beans and I cannot believe I waited this long. No bitterness, no aftertaste, just smooth. I've kept a batch in the fridge every week since and it has completely ruined me for anything else.
Same, I keep a jar going constantly. If you haven't tried it with a splash of heavy cream yet, do it. That's how I drink mine every morning.