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Low-Carb Black Widow Cocktail

★★★★★★★★★★
4.2 stars, average of 87 ratings

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Low-Carb Black Widow CocktailPin itFollow us 148.4k

This spooky low-carb cocktail is perfect for Halloween! I used homemade blackberry-lime syrup and substituted the commonly used simple syrup with powdered Erythritol. There are other options you can try:

  • Skip the powdered sweetener in the blackberry juice and make your own simple syrup like in this Spicy Low-Carb Margarita. The only drawback of making simple syrup this way is that it may partially crystallize once it's chilled.
  • You could use NuNaturals Simple Syrup. Apart from plain simple syrup, it's available in several different flavors such as Ginger Syrup which worked wonderfully in my Keto Ginger & Rhubarb Creamsicles. Just remember to use the recommended amount as too much would make your cocktail way too sweet.
  • Lastly, you can just use a few drops of stevia. NuNaturals are my favorite as they don't taste bitter.

Note that this recipe makes about 2 1/4 cups (530 ml/ 18 fl oz) blackberry juice. This will be enough for 6 cocktails. Fibre is counted partially (25%) as most of the pulp and seeds are discarded.

Looking for a spooky treat? Try my Halloween Keto Pizza, Spooky Eyeball Cookies, Cheesy Keto Spinach Crackers, and even more Halloween Keto Recipes.

Hands-on Overall

Serving size cocktail

Allergy information for Low-Carb Black Widow Cocktail

✔  Gluten free
✔  Dairy free
✔  Egg free
✔  Nut free
✔  Nightshade free
✔  Pork free
✔  Avocado free
✔  Coconut free
✔  Fish free
✔  Shellfish free
✔  Beef free
Pescatarian
Vegetarian
Vegan

Nutritional values (per cocktail)

Net carbs4.7 grams
Protein1.1 grams
Fat0.4 grams
Calories166 kcal
Calories from carbs 71%, protein 16%, fat 13%
Total carbs5.7 gramsFiber1 gramsSugars0 gramsSaturated fat0 gramsSodium8 mg(0% RDA)Magnesium17 mg(4% RDA)Potassium135 mg(7% EMR)

Ingredients (makes 1 cocktail)

Homemade blackberry syrup:
  • 450 g fresh or frozen blackberries (1 lb)
  • 1/4 cup lime or lemon juice (1-2 pieces)
  • 1 cup water (240 ml/ 8 fl oz)
  • 1/2 cup powdered Allulose or Erythritol (80 g/ 2.8 oz)
Each Cocktail:
  • 90 ml homemade blackberry syrup (3 fl oz)
  • 1/4 cup vodka (60 ml/ 2 fl oz)
  • ice
  • Optional: sparkling water (soda water) to top up
  • Optional: acai powder or freeze-dried berry powder mixed with granulated Erythritol, and fresh blackberries for decoration

Instructions

  1. Place the blackberries in a saucepan. Low-Carb Black Widow Cocktail
  2. Add the lime juice and water. Bring to a boil over a medium heat. Boil for 3-5 minutes. Low-Carb Black Widow Cocktail
  3. Once softened, mash the blackberries using a fork.
  4. Pour through a fine mesh sieve and using a spoon, press the blackberries through so that only the skins and seeds remain in the sieve. Low-Carb Black Widow Cocktail
  5. Pour into a jar. The juice should be quite thick, the consistency of syrup.
    Note: this recipe makes about 2 1/4 cups (530 ml/ 18 fl oz) blackberry syrup. This will be enough for 6 cocktails. Low-Carb Black Widow Cocktail
  6. Add the powdered sweetener and mix until combined. Let it cool and refrigerate until ready. The syrup can be stored in the fridge in a sealed bottle or jar for up to a week. Low-Carb Black Widow Cocktail
  7. To serve, optionally decorate your cocktail glasses by dipping the rims in water and then in a mixture of acai powder (or any berry powder). Fill each glass with ice and pour in the vodka. Low-Carb Black Widow Cocktail
  8. Add the sweetened blackberry juice. Low-Carb Black Widow Cocktail
  9. Decorate with more fresh blackberries or mint leaves and serve. Low-Carb Black Widow Cocktail

Black Widow Cocktail (KetoDiet blog)
Step by Step

★★★★★★★★★★
4.2 stars, average of 87 ratings
Black Widow Cocktail (KetoDiet  blog)
Low-carb cocktail with homemade blackberry-lime syrup and vodka. This is the perfect sugar-free and low-calorie cocktail for your Halloween table!
Hands on10m
Overall30m
Servings1
Calories166 kcal
Pin it

Ingredients

  • 450 g fresh or frozen blackberries (1 lb)
  • 1/4 cup lime or lemon juice (1-2 pieces)
  • 1 cup water (240 ml/ 8 fl oz)
  • 1/2 cup powdered Allulose or Erythritol (80 g/ 2.8 oz)
  • 90 ml homemade blackberry syrup (3 fl oz)
  • 1/4 cup vodka (60 ml/ 2 fl oz)
  • ice
  • Optional: sparkling water (soda water) to top up
  • Optional: acai powder or freeze-dried berry powder mixed with granulated Erythritol, and fresh blackberries for decoration

Instructions

  1. Place the blackberries in a saucepan.
  2. Add the lime juice and water. Bring to a boil over a medium heat. Boil for 3-5 minutes.
  3. Once softened, mash the blackberries using a fork.
  4. Pour through a fine mesh sieve and using a spoon, press the blackberries through so that only the skins and seeds remain in the sieve.
  5. Pour into a jar. The juice should be quite thick, the consistency of syrup.
    Note: this recipe makes about 2 1/4 cups (530 ml/ 18 fl oz) blackberry syrup. This will be enough for 6 cocktails.
  6. Add the powdered sweetener and mix until combined. Let it cool and refrigerate until ready. The syrup can be stored in the fridge in a sealed bottle or jar for up to a week.
  7. To serve, optionally decorate your cocktail glasses by dipping the rims in water and then in a mixture of acai powder (or any berry powder). Fill each glass with ice and pour in the vodka.
  8. Add the sweetened blackberry juice.
  9. Decorate with more fresh blackberries or mint leaves and serve.

Nutrition (per cocktail)

Calories166kcal
Net Carbs4.7g
Carbohydrates5.7g
Protein1.1g
Fat0.4g
Saturated Fat0g
Fiber1g
Sugar0g
Sodium8mg
Magnesium17mg
Potassium135mg

Detailed nutritional breakdown (per cocktail)

Net carbsProteinFatCalories
Total per cocktail
4.7 g1.1 g0.4 g166 kcal
Homemade Blackberry Juice (KetoDiet blog)
4.7 g1.1 g0.4 g38 kcal
Vodka, distilled alcoholic beverage (~40% vol)
0 g0 g0 g128 kcal
Ice cubes
0 g0 g0 g0 kcal

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Martina Slajerova
Creator of KetoDietApp.com

Martina Slajerova

I changed the way I ate in 2011, when I was diagnosed with Hashimoto’s, an autoimmune disease that affects the thyroid. I had no energy, and I found it more and more difficult to maintain a healthy weight.

That’s when I decided to quit sugar, grains, and processed foods, and to start following a whole-foods-based ketogenic approach to food.

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Comments (10)

So excited to try this for Halloween! Do you think it would be just as good with gin instead of vodka?

I don't see why not! Gin is a great alternative 😊

★★★★★★★★★★

This cocktail is such a great idea for Halloween! I've made the syrup just to drink with water and made my first cocktail with it last night. So good! Perfect for a spooky night 😊

Glad you enjoyed 😊

Wow, this is a brilliant idea, Martina! I love the sound of the homemade blackberry syrup. I don't have Allulose, is there a big difference if I use Erythritol?

Hi Emilie, there is a difference as allulose doesn't crystallize once refrigerated like erythritol does. The difference is not huge but you will get better results with allulose.

★★★★★★★★★★

Absolutely LOVE the syrup, I haven't tried this cocktail yet but the syrup is a must. I kept mine in the fridge for a good 2 weeks and it was still fine.

Thank you! I'd say a week for sure, maybe more if sealed properly.

Totally love the spooky vibes this brings! How long will the blackberry syrup keep if I store it in the fridge?

Hi Emma, I keep this for up to a week but I've seen other sharing that it lasts for longer. As long as it's kept in a sealed jar, it will last for a week or two.