Sweet Potato Tempura (3 Japanese Ways to Make)

Method13 steps · about 1 hr

1. 1

   Step 1: Measure the 75 ml batter water into a jug and refrigerate it. Chill the carbonated water (50 ml) too, preferably in an unopened bottle, and measure its 50 ml after chilling. Keep both cold for 30 minutes while you prepare the remaining ingredients.

   Chill batter waters · 30 minUses 75 ml water for the batter, chilled · 50 ml carbonated water, chilled

   
2. 2

   Step 2: Sift the 15 g cornstarch and 75 g cake flour into a bowl and mix. Refrigerate this dry mixture for 30 minutes alongside the waters.

   Chill dry batter mixture · 30 minUses 15 g cornstarch · 75 g unbleached cake flour for the batter; all-purpose flour may be substituted

   
3. 3

   Step 3: While the batter ingredients chill, scrub the 600 g sweet potato and trim the ends. Choose thin rounds around 1 cm thick, sticks with some skin on every piece, or thick rounds 1.5–2 cm thick. For thick rounds, score a shallow cross on both faces.

   Uses 600 g Japanese sweet potato (satsumaimo), scrubbed with skin on · Separate water for scrubbing the sweet potato

   
4. 4

   Step 4: Cover the cut sweet potato with separate cold water and soak for 10 minutes while the batter ingredients continue chilling.

   Soak cut sweet potato · 10 minUses Cut sweet potato, chosen shapes · Enough separate cold water to cover the cut sweet potato; drain after soaking

   
5. 5

   Step 5: After the batter ingredients have chilled for the full 30 minutes, start heating the frying oil to 160°C (320°F).

   Uses Cooking oil, enough for deep-frying in your pot

   
6. 6

   Step 6: Choose one binder. Whisk a few tablespoons taken from the chilled 75 ml batter water with either the ½ tbsp Japanese mayonnaise or ½ small whisked egg. Add all the remaining water from that same 75 ml supply and all the chilled 50 ml carbonated water.

   Uses Chilled still batter water, 75 ml supply · Chilled carbonated water, 50 ml supply · ½ tbsp egg-containing Japanese mayonnaise, only for the mayonnaise binder option · ½ small whisked egg instead of the ½ tbsp mayonnaise; choose one binder

   
7. 7

   Step 7: Add all the chilled flour-and-cornstarch mixture to the chosen liquid mixture in three additions. Use chopsticks to draw crosses gently through it. Leave small lumps and avoid whisking or overmixing.

   Uses All chilled flour-and-cornstarch mixture · Liquid mixture with the chosen binder

   
8. 8

   Step 8: If using, add the two ice cubes to the batter to keep it very cold. Keep the batter chilled between frying batches.

   Uses Mixed tempura batter · 2 ice cubes, optional

   
9. 9

   Step 9: Drain the soaked sweet potato and dry it thoroughly with kitchen paper. Dust the pieces with a thin layer of the extra flour, shaking off any excess. Keep the cold batter ready for dipping immediately before frying.

   Uses Soaked sweet-potato pieces, separated from soaking water · Extra flour, only enough to coat the drained sweet-potato pieces lightly

10. 10

    Step 10: For thin rounds or sticks only, check that the oil is at 160°C (320°F); a drop of batter should sizzle and float. Dip a small batch of pieces into the cold batter and immediately lower them into the oil without crowding. Fry for about 4–5 minutes, turning halfway through, until the batter is crisp and the centres are tender when pierced. Repeat with the remaining thin pieces, keeping the batter cold between batches. Skip this route if you chose only thick rounds.

    Fry thin rounds or sticks, per batch · 4 minUses Dried and lightly floured thin rounds or sticks, only for this cut · Cold batter needed to coat the thin-cut batches · Hot frying oil

    
11. 11

    Step 11: For thick rounds only, dip a small batch into the cold batter and fry in the same 160°C (320°F) oil without crowding. Turn during cooking and use about 6–7 minutes as the guide; the coating should be crisp and a skewer should pass easily through the centre. Repeat for the remaining thick rounds, keeping the batter cold between batches. Skip this route if you chose only thin rounds or sticks.

    Fry thick rounds, per batch · 6 minUses Dried and lightly floured thick rounds, only for this cut · Cold batter needed to coat the thick-round batches · Hot frying oil

12. 12

    Step 12: Transfer each cooked batch to a wire rack as soon as it is done and let excess frying oil drip off. Keep the cooked pieces separate from any unused batter.

    Uses Cooked thin-round or stick tempura, if chosen · Cooked thick-round tempura, if chosen

    
13. 13

    Step 13: Serve the hot drained tempura as four side portions. For leftovers, cool promptly, cover and refrigerate for 1–2 days. Alternatively, freeze the cooled pieces in a sealed bag for up to 1 month, keeping them separate so they do not stick. Thaw and warm through in the oven before serving.

    Uses All drained sweet-potato tempura