Home » Crunchy, Japanese-Style Keto Tempura Batter

Crunchy, Japanese-Style Keto Tempura Batter

If you are missing crispy, deep-fried tempura on a keto diet, this low-carb, grain-free, and gluten-free batter will bring the joy back to, or even inspire, your own Japanese night in (and don’t forget to make a Quick Keto Yum Yum Sauce to dip it all in)!

keto tempura batter food

Japanese cuisine may be one of the healthiest on the planet, traditionally centering around plenty of vegetables, seafood, lean meats, and minimally processed foods served with small portions of rice.

However, tempura is a preparation that is also traditionally Japanese, even though it involves a method of heavy battering and deep-frying foods in oil.

Tempura was one of those foods that I used to enjoy whenever visiting our favorite teppanyaki restaurants.

My family and I would typically order some of these delicious battered vegetables as an appetizer before the main event of grilled meats and fried rice – it is the only other time they prefer fried vegetables over this fried zucchini recipe I make a lot at home!

Nowadays I make my own keto version of tempura, with a batter that rivals any Japanese steakhouse!

And whenever I serve it alongside this yum yum sauce, my husband and kids don’t even realize that it’s all keto!

So if you are looking for a low-carb version of tempura to curb your deep-fried cravings, then read on!

What Is Tempura?

Tempura is a common Japanese dish of seafood, meat, or vegetables that are battered and quickly deep-fried in oil with a high smoke point like vegetable, canola, or sesame oil. This batter is generally made up of:

  • all-purpose flour
  • eggs
  • ice cold water or sparkling water
  • baking soda or baking powder

How Do You Make A Keto Tempra Batter?

keto tempura batter ingredients

Making a low-carb, or keto, tempura batter is as easy as substituting the all-purpose flour for an unflavored whey protein powder to get the meat and vegetables extra crispy (the whey protein must be unflavored so that there is no added flavor or sugars in the batter)!

The remaining ingredients include:

  • Sparkling water – the carbonation makes the batter lighter and crispier
  • Egg – gives the batter structure
  • Xanthan gum – acts as a binding agent for the batter
  • Baking soda – makes the batter fluffier and crispier
  • Sea salt – seasons the batter

How Many Carbs Are In Whey Protein Powder?

Unflavored whey protein powder (concentrate) has 1 gram of carbohydrate and unflavored whey protein powder isolate has 0 (zero) grams of carbohydrates per 29-gram serving or 1 scoop.

What Is The Difference Between Whey Concentrate and Whey Isolate Protein?

  • Whey protein (concentrate) – a concentrated group of proteins found in cow’s milk after the curds are separated for cheese-making and have varying amounts of lactose (sugar).
  • Whey protein isolate – is processed further to reduce the lactose content in the milk proteins, making it a better option for people who are lactose intolerant.

Here are two of my favorite brands:

What Can You Fry In A Keto Tempura Batter?

Most any seafood and vegetables can be fried in a keto tempura batter – feel free to experiment, but here are a few common examples of each:

Seafoodshrimp/prawn (ebi), squid, crab, scallop, cod, eel, sea bass, salmon, catfish, pollock
Vegetablescauliflower, broccoli, carrots, green beans, eggplant, asparagus, mushrooms, bell peppers, onions, bamboo shoots, zucchini, lotus flower root
Proteinboneless, skinless chicken (breast, thigh), pork tenderloin (fillet), sirloin, tenderloin, New York Strip (striploin), ribeye, extra firm tofu

More Keto Recipes To Enjoy…

  • protein-packed low-carb tortillas
  • keto seed crackers recipe baked crackers
  • fluffy keto oat fiber rolls

How to Prepare Foods To Fry In A Keto Tempura

keto tempura batter food prep

Ideally, the tempura ingredients should be sliced as uniformly as possible so that the cooking times are similar due to the high heat and quick frying method.

Here is a quick guide for prepping suggested foods for a keto tempura batter:

boneless beef, chicken, fish fillets, tofu, shellfishCut into 1-inch (2.5 cm) cubes or 1/2-inch (1.25 cm) wide strips and 3-4 inches (7.5-10 cm) long
onionCut into 1-inch (2.5 cm) thick rings
zucchini, eggplant, lotus flower root, bell peppersSlice into ovals or strips 1/2 inch (1.25 cm) thick and 3-4 inches (7.5-10 cm) long
carrots, bamboo shoots Cut into ovals or strips 1/4 inch (.5 cm) thick
sweet potatoesMake 1-inch cubes or 1/4 inch (.5 cm) thick and 3-4 inches (7.5-10 cm) long
broccoli, cauliflowerCut off the stems and divide florets into 1/2 inch (1.25 cm) wide pieces
mushroomsTrim away excess stems and fry cap whole or slice into halves or quarters (depending on the size)
asparagusRemove the woody base and leave whole
green beansTrim the ends and leave whole

What Is The Best Oil Temperature For Frying Keto Tempura And How Much Do I Need?

The best temperature for frying keto tempura is in oil heated to around 175°C (350°F) in 3-4 inches (7.5-10 cm) of oil in a large pot. I recommend using a thermometer to monitor the temperature: any hotter and you risk undercooking poultry before the whey protein batter is cooked through and browned. This is why it is so important to cut pieces of poultry and pork into smaller, uniform sizes before frying (follow the suggested food preparation guide above)!

Study: Chicken and other foods fried in whey protein may have up to 30 percent less absorption of oil due to it’s characteristic of being an oil barrier, with minimal effect to the color, taste, and texture of the fried foods.

(Dragich AM, Krochta JM. Whey protein solution coating for fat-uptake reduction in deep-fried chicken breast strips. J Food Sci. 2010 Jan-Feb;75(1):S43-7. doi: 10.1111/j.1750-3841.2009.01408.x. PMID: 20492201.)

What You Need To Make Keto Tempura Batter


  • mixing bowl
  • heavy-bottom pot, wok, or deep fryer (for frying)
  • deep-fry or candy thermometer (to measure oil temperature)
  • tongs, strainer, or chopsticks (for removal)
  • plate
  • paper towels

How To Make Keto Tempura

Step 1:

Prepare your vegetables and/or meat by cutting or slicing them into uniform pieces.

keto tempura batter food prep

Step 2:

Preheat the oil. In a mixing bowl, prepare the tempura batter by mixing the whey protein, xanthan gum, salt, and baking soda. Add in the eggs and cold sparkling water. Whisk everything together until smooth.

  • keto tempura batter ingredients in a bowl
  • keto tempura batter whisked in bowl

Step 3:

Coat the vegetable pieces in the tempura batter and allow the excess to drip away.

  • keto tempura batter mushrooms
  • keto tempura batter zucchini
  • keto tempura batter eggplant

Step 4:

Carefully place the battered pieces into the oil, only a few at a time (do not overcrowd the pot). Fry the pieces 1-2 minutes before flipping and cooking an additional 1-2 minutes (or cook 3-4 minutes submerged in a deep fryer).

keto tempura batter zucchini frying

Step 5:

Remove the tempura pieces from the oil and strain of a plate covered with a paper towel. Season with salt while it’s still hot. Serve immediately.

keto tempura batter drained and seasoned vegetables

Tips For The Keto Tempura Batter

  • If the batter gets thick after mixing, add 1-2 tablespoons of ice cold sparkling water at a time to thin it out a little – however, the tempura batter should still stick to foods without it being too thin.
  • Stir the batter in between coatings to make sure that it is smooth before dipping more peices in.
  • Try to use a metal bowl for mixing your keto batter – it will help to keep it cold while you are fying your tempura pieces.
  • Refrigerate the metal mixing bowl for at least 30 minutes before mixing your tempura batter – this will also help to keep the batter cold.
  • If you do not have a metal bowl or if you are frying a lot of food, place your bowl of tempura batter over another larger bowl filled with ice while you work – the tempura will fluff more and be crispier once the cold batter meets the hot oil.

What to Serve With Keto Tempura

  • Serve the tempra on a bed of “zoodles,” spiralized carrots, cucumbers or daikon radish
  • Tentsuyu – a dipping sauce made with dashi, soy sauce, mirin, and sugar
  • Japanase soy sauce with minced ginger and chili flakes
  • Wasabi-mayonaise

Try This Other Gluten-Free Fried Zucchini Recipe

The Recipe:

keto tempura batter food

Crispy Keto Tempura

This keto tempura batter is made with whey protein powder and is a delicious, crispy, low-carb, and gluten-free alternative to traditional Japanese tempura and has less than 1 gram of carbs per serving!
4.67 from 15 votes
Prep Time 5 mins
Cook Time 15 mins
Total Time 20 mins
Course Appetizer, Main Course
Cuisine Japanese
Servings 2
Calories 467 kcal



Keto Tempura Batter

Suggested Vegetables (Follow slicing guides in the post)

  • 1 small eggplant
  • ½ medium zucchini
  • 1 cup button mushrooms

Suggested Protein (Follow dimension guides in the post)

  • 1 chicken breast

Oil For Frying

  • 3-4 inches vegetable, canola, or sesame seed oil in a pot (any oil with a high smoking point will do)


  • Slice vegetables and protein in uniform pieces for even cooking (check the suggested slicing guides in the post above).
  • Preheat oil in a large pot or fryer to 350° F (175° C).
  • In a mixing bowl place the whey protein, xanthan gum, baking soda, and salt together and mix. Add the eggs and cold sparkling water. Whisk until a smooth batter forms.
  • Place the sliced vegetables and/or protein into the tempura batter and evenly coat. Let the excess batter drip before placing the pieces into the pot of hot oil or deep fryer.
  • Fry the tempura pieces for 1-2 minutes before turning over in the hot oil. Fry an additional 1-2 minutes until the pieces are golden brown. If cooking in a deep fryer, allow the pieces to brown for a total of 3-4 minutes before removing.
  • Remove the tempura pieces from the oil and drain them on a plate lined with paper towels to drain. Season with salt and serve immediately.


(Nutrition information is per serving for the keto tempura batter ONLY using ISOPURE whey protein isolate with two tablespoons of oil absorbed.)  If you would like to check nutrition info with your chosen foods, check with a website like https://www.nutritionvalue.org/)
  • How to tell if your oil is hot enough without a thermometer: place a wooden spoon into a pot of oil with the handle side in.  If no bubbles start dispersing around the spoon, then it’s not hot enough –  check again in a minute or two.  When placed in again and the bubbles begin to form around the spoon, the oil is hot enough.
  • Season the tempura immediately while the pieces are draining on the paper towels so that it “sticks.” 
  • Do not over-crowd the pot when frying:  it will decrease the oil temperature too much and result in soggy tempura; the pieces also need adequate room to expand while frying.


Sodium: 1648mgCalcium: 74mgSugar: 0.2gFiber: 0gPotassium: 69mgCholesterol: 201mgCalories: 467kcalSaturated Fat: 5.6gFat: 33gProtein: 45gCarbohydrates: 0.4gIron: 0.9mg
Keyword batter, gluten-free, Japanese, keto, tempura
Tried this recipe?Let us know how it was!

Are you missing tempura on keto?

Will you be trying this recipe? Let us know in the comments!



  1. Carl
    April 2, 2022 / 7:25 pm

    ? Quantity of whey required. 6 tablespoons gives me about 36 g weight. Threw in another 6 tablespoons. Crispy outcome

    • familyandglamour
      April 3, 2022 / 2:01 pm

      Hi Carl! I am happy to hear that you enjoyed the keto tempura batter!
      My brand of whey protein powder (not isolate) weighs approximately 90 grams per 6 tablespoons (15 grams per tbsp).
      Perhaps the weight of the powders (whey vs. isolate) or brands may vary. Check your specific label for the exact weight and measurements – or as you have done – added the amount of protein powder for a consistency that you enjoy best! Thank you for the feedback!

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