Zucchini tempura

Japanese tempura of zucchini in a feather-light batter

Origin: Edo Period Japan

From the journey of Zucchini.

Tempura's origin is one of the most precise cultural transfer stories in culinary history. Portuguese Jesuit missionaries arrived in Japan in the 1540s and brought with them a Lenten tradition of frying vegetables and seafood in batter during the quatuor anni tempora; the 'four seasons' fasting periods of the Catholic calendar. The technique was adopted by Japanese cooks in the port cities of Nagasaki and Edo (modern Tokyo) and then transformed, with the precision and refinement that characterise Japanese culinary evolution, into something entirely distinct from its Portuguese source: the batter made ice-cold to inhibit gluten development, mixed minimally to preserve a rough, uneven texture that fries into a transparent, feather-light lacework rather than a thick coating, and cooked in refined oil at a precisely maintained temperature that produces a crust so light it barely qualifies as a crust. The Portuguese original was a rough country technique; the Japanese refinement is a statement of mastery. Kabocha squash has always been among the classic tempura vegetables: its sweet, dense flesh contrasting with the ethereal batter. Zucchini, a later addition to the Japanese kitchen, is a natural extension of this tradition: its high water content requires the oil temperature to be correct and the batter to be very light, but when done well, the result (translucent, crisp, with the gentle sweetness of the zucchini showing through the almost invisible coating) is one of the most elegant fried preparations in any cuisine.

Ingredients

Main

400 g zucchini (about 3 medium), cut into batons 8cm long and 1cm wide, or into diagonal slices 1cm thick

Batter

120 g plain flour (not strong bread flour, low-protein flour is better)
1 egg yolk
180 ml ice-cold water (put the measured water in the freezer for 15 minutes before using)

Frying

vegetable or sunflower oil, for deep frying

Tentsuyu

200 ml dashi (or diluted ready-made dashi powder in water)
3 tbsp mirin
3 tbsp soy sauce (usukuchi light soy sauce if available)
2 tbsp finely grated daikon radish
1 tsp finely grated fresh ginger

Method

Make the tentsuyu dipping sauce: combine dashi, mirin, and soy sauce in a small saucepan and bring just to a simmer. Remove from heat. The sauce should be savoury, slightly sweet, and fragrant. Serve at room temperature with the grated daikon and ginger stirred in (or provided separately for guests to add to taste).
Prepare the zucchini: cut into batons or diagonal slices no thicker than 1cm. Pat the surfaces completely dry with kitchen paper; surface moisture is the enemy of crisp tempura. Any water on the surface will cause the batter to steam rather than fry, producing a soft coating.
Heat the oil in a deep, heavy pan to 175–180°C. Use a thermometer; temperature precision matters more in tempura than in almost any other frying preparation. Too low and the batter absorbs oil and becomes heavy; too high and the batter browns before the zucchini cooks through.
Make the batter at the last possible moment, immediately before frying. In a cold bowl (chill it in the freezer for a few minutes), quickly mix the egg yolk and ice-cold water with chopsticks or a fork; just 2–3 stirs. Add the flour all at once and mix with 4–5 rough strokes only. The batter should be lumpy, streaky, and barely combined; this is correct. Under-mixing is better than over-mixing.
Dip each zucchini piece into the batter, letting excess drip off, then lower gently into the oil. Fry in small batches of 4–5 pieces; never crowd the pan. Cook for 2–2.5 minutes, turning once, until the batter is pale gold and just barely set; not dark, not deeply golden. Remove with a wire skimmer and drain briefly on a wire rack (not kitchen paper, which traps steam). Serve immediately.

Notes

The choice of oil affects flavour significantly: neutral vegetable oil is standard; sesame oil blended at 10% with vegetable oil gives a very slightly nutty quality favoured in some traditional establishments. The batter can be enriched with a spoonful of vodka (which evaporates faster than water, further reducing gluten development). Zucchini flowers dipped in plain unseasoned tempura batter and fried for 60 seconds are one of the most spectacular uses of this technique.

The Gastrographer

Name: Zucchini tempura
Prep time: 15 min
Cook time: 15 min
Total time: 30 min
Yield: 4
Cuisine: Edo Period Japan
Ingredients: 400 g zucchini (about 3 medium), cut into batons 8cm long and 1cm wide, or into diagonal slices 1cm thick; 120 g plain flour (not strong bread flour, low-protein flour is better); 1 egg yolk; 180 ml ice-cold water (put the measured water in the freezer for 15 minutes before using); vegetable or sunflower oil, for deep frying; 200 ml dashi (or diluted ready-made dashi powder in water); 3 tbsp mirin; 3 tbsp soy sauce (usukuchi light soy sauce if available); 2 tbsp finely grated daikon radish; 1 tsp finely grated fresh ginger

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Journey Point Map Key

Ingredient originTrade or transit route

Became a culinary stapleColonial / trade control