Keto Lemonade
Published August 4, 2019 • Updated February 26, 2026
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I make this keto lemonade all summer long, and it's the first thing I reach for when it hits 90 degrees. Tart, sweet, four ingredients, and it tastes like the real thing.
I start making this every Memorial Day weekend, and I don’t stop until September. It’s the drink I reach for when it’s 95 degrees and I’ve been outside all day. Four ingredients, ten minutes, and a pitcher that barely survives the afternoon in my house.
The thing most people get wrong with sugar free lemonade is the sweetener ratio. I’ve tested this dozens of times, and Swerve confectioners dissolves the smoothest in cold water. No grit, no weird cooling effect. If you want to use allulose or monk fruit, go for it, but start with half the amount and taste as you go because they hit differently than erythritol-based sweeteners.
The real secret is the salt. Two pinches. I know it sounds strange (Nicole, one of my readers, thought the same thing), but salt suppresses bitterness and makes the sweet perception jump. It’s the same reason salted caramel works. Once I started adding it, I couldn’t go back to lemonade without it.
I squeeze my lemons fresh every single time. Bottled juice doesn’t come close because pasteurization kills the bright, tart punch you need. One medium lemon gives me about 3 tablespoons of juice, so I go through 5-6 lemons per batch. Yes, it’s more work, but this is a low carb lemonade where the ingredient quality is the whole point.
When I want to mix things up, I throw in about 1/2 cup of frozen strawberries right into the pitcher and let them thaw for 10 minutes. They tint the whole thing pink and add just enough berry sweetness without wrecking the macros. If you like that idea, my keto strawberry lemonade takes it even further with a full strawberry puree. I also make a frozen version when I want something slushy, and on weekend evenings a vodka lemonade happens pretty regularly.
One of my readers, Angela, told me this tasted exactly like the lemonade her mom used to make every summer. That’s the kind of thing that tells me the ratio is right. 4.6g net carbs per serving, and it actually tastes like real lemonade, not a diet compromise.
This keeps in the fridge for about 5 days in a sealed pitcher. I’ve pushed it to a week and it’s still safe, but the lemon flavor dulls noticeably after day 5. The sweetener settles too, so give it a stir before you pour. For a single glass, I use 1/4 cup fresh lemon juice, 1 cup water, and 2 tablespoons Swerve with a tiny pinch of salt.
If you’re looking for more low carb drinks for summer, my activated charcoal lemonade is a dramatic one for parties, my keto mojito brings fresh mint into the mix, and my dalgona coffee is my other warm-weather obsession when I need caffeine instead of citrus.
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Ingredients
1 cup of freshly squeezed lemon juice -
4 cups of water
-
1/2 to ¾ c confectioners Swerve or use sweetener of choice
-
two pinches of salt
Step by Step Instructions
Step by Step Instructions
Squeeze it
Using a juicer or a citrus squeezer, squeeze the juice out of the lemons until you have 1 cup of freshly squeezed juice.
Stir it
Stir in water and confectioner’s Swerve. Add in two pinches of salt and mix until combined.
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
Can I use bottled lemon juice instead of fresh?
I've tried both, and fresh wins every time. Bottled lemon juice is pasteurized, which strips out the bright, tart punch that makes this taste like real lemonade. Fresh lemons give me about 3 tablespoons of juice each, so I squeeze 5-6 for a full batch. The extra few minutes are worth it.
What is the best sweetener for lemonade with no aftertaste?
I've tested Swerve confectioners, allulose, and monk fruit in this recipe. Swerve dissolves the cleanest in cold water with no grit. Allulose is my second pick because it has zero glycemic impact and no cooling effect, but you need less of it (start with 1/3 cup). Monk fruit works too, though I find it needs a tiny bit more salt to balance. For a low carb lemonade with zero aftertaste, allulose or Swerve confectioners are my go-to picks.
How many net carbs are in this lemonade?
My recipe comes out to 4.6g net carbs per serving. That's based on fresh lemon juice (which has natural sugars) and Swerve (which is 0g net). I've run the numbers across different batch sizes, and each lemon contributes roughly 1.5g net carbs. So if you scale up, you can calculate your own totals from there.
Does keto lemonade break a fast?
It depends on your fasting protocol. I drink this during my eating window, but the lemon juice does contain a small amount of natural sugar (about 4.6g net carbs per serving). If you're doing strict water-only fasting, that could technically break it. If you follow a more relaxed approach where anything under 50 calories is fine, a glass of this sits well within that range.
How do I make a single serving?
I do this all the time when I don't want a full pitcher. My single-serving ratio is 1/4 cup fresh lemon juice, 1 cup cold water, and 2 tablespoons Swerve confectioners with a tiny pinch of salt. Stir it well (the Swerve needs a good 30 seconds to dissolve in cold water), pour over ice, and you're set.
How long does homemade keto lemonade last in the fridge?
I keep mine for up to 5 days in a sealed pitcher, and it's still good at that point. I've pushed it to 7 days and it was safe to drink, but the bright lemon flavor starts to dull noticeably after day 5. The sweetener also settles to the bottom, so always give it a good stir before pouring.
Can I make this lemonade sparkling?
I do this when I want something fizzy. Mix the lemon juice and sweetener with just 1 cup of still water first (so the Swerve dissolves properly), then top off with 3 cups of cold sparkling water right before serving. Don't stir aggressively or you'll lose the bubbles. If you like sparkling drinks, my hard seltzer strawberry slushy is another favorite of mine.
Can I use this as a base for cocktails?
I use this as my cocktail mixer all summer. It pairs perfectly with vodka (about 1.5 oz per glass), and I've also mixed it with tequila for a lazy lemonade margarita. My keto margarita is the more polished version of that idea. Just keep in mind the alcohol adds calories even though the carbs stay low.
My kids love this sugar-free lemonade all year long – not just in the summer. A nice tall glass is my favorite drink in the summertime, especially on a hot sunny day.
Each time I make up a batch of this fresh squeezed lemonade, it barely lasts a day in our house. We drink it so fast! Luckily, it is so easy to make more. All you need is a couple of lemons, water, salt, and a sugar-free sweetener like monkfruit, erythritol, or stevia.
You can juice a lemon a few different ways!
To juice a lemon,
Leftover lemonade stores well in the fridge – either in the pitcher or an air-tight container. It stays fresh for several days.
You can also freeze this lemonade! Pop it in a Ziploc bag or just freeze the concentrate (lemon juice, sweetener and salt without the water). Great to have on hand when company shows up and you want to serve a refreshing glass of homemade lemonade.
To thaw, place the bag on the counter or in the fridge for several hours. Or drop it in a bowl of warm water for a quicker thaw.
Serve over ice.
Would granulated monk fruit work if I'm out of confectioners Swerve, or does it need to be powdered to dissolve in cold water?
I've been on keto for 8 months and honestly thought I'd never drink real lemonade again. Made this yesterday and almost cried. It tastes exactly like the lemonade my mom used to make every summer, tart and sweet and cold. I can't believe something this simple has been here the whole time.
The tart-sweet thing is real. I make this every couple weeks in summer, sometimes with a handful of frozen strawberries thrown in. Your mom's version was probably pretty close to this ratio.
I thought the pinch of salt was a little strange but it really brings out the sweet taste! I love this lemonade!
Salt in lemonade reads weird until you taste it. It's the same reason I add a pinch to almost every keto dessert - it makes the sweetener taste closer to real sugar.