Portuguese Egg Tarts (葡式蛋挞)

They look more like curry puffs! That's what one reader says about Rasa Malaysia's Portuguese egg tarts.

Indeed, her tarts don't have any of the signature burn marks. To me, what's supposed to be the custard looks more like an omelette . . . or maybe quiche filling.

What's wrong with Rasa Malaysia's recipe?

Portuguese egg tarts should use puff pastry but Rasa Malaysia uses shortcrust. To get the hallmark splodges on the custard, the tarts have to be baked at a very high temperature, about 250°C. That would have shortcrust pastry incinerated. That's why Rasa Malaysia bakes her tarts at 200°C. At that temperature, the shortcrust pastry doesn't burn but then neither does the custard even when it's overcooked (you can tell from the leathery, crumpled top).

If you show Rasa Malaysia's tarts to the people in Lisbon or Macau, no one would recognize them as Portuguese egg tars.

If the shortcrust pastry in Rasa Malaysia's recipe is replaced with puff pastry and the oven temperature increased to 250°C, would the egg tarts turn out OK?

Nope, because her custard filling doesn't have enough milk. Milk forms a film of protein when heated. The custard has to form the same film and it's that film that's burnt, not sugar or custard. Not enough milk means no film because there isn't enough protein. No film means no burn marks even at 250°C, at least not before the pastry's burnt.

A lot of people think PETs' burnt splodges are bits of caramelized sugar. But sugar, or rather sucrose, turns black only when it hits at least 210°C. At that temperature, the pastry would turn black too. Milk proteins, OTOH, brown at a much lower temperature. That's why it's burnt when the pastry and sugar aren't.

The surface of the custard filling is shiny. The shine is due to melted sugar which separates from the custard mixture when heated. It then bubbles up to the top, giving the custard its shiny look.

Separated sugar's a good thing except not all of it finds its way up if there's a lot. Some of it may sink to the bottom of the tart and turn the pastry soggy. How to tackle this problem? By controlling the amount of sugar that separates from the custard mixture. How? With cornflour. It stabilizes the custard, and reduces the amount of sugar separated.

Activating the binding quality of cornflour requires the custard mixture to be heated to the right consistency. If it's too thick, it'll turn into scrambled eggs when it's baked. If it's too thin, it'll allow too much sugar to separate, turning the pastry soggy.

Even store-bought tarts may have a sunken top. Just look at the PET photos online. Lord Stow's, the gold standard, are picture perfect only some of the time, i.e. when there's a press review!

How to stop the custard from sinking as it cools down so that the top stays level?

Again by stabilizing it with cornflour. You see how important the cornflour is but it's missing from Rasa Malaysia's recipe?

If you use readymade pastry shells, making Portuguese egg tarts is a cinch . . . Well, it is provided you're not using a crap recipe like Rasa Malaysia's.

MACAU STYLE PORTUGUESE EGG TARTS (葡式蛋挞) (Recipe for 9 tarts) 60 g dairy cream, 35% fat 60 g sugar 2 egg yolks, 30 g 1 tbsp cornflour 260 g full-fat fresh milk ½ tsp vanilla extract 9 frozen puff pastry shells, each measuring 7 x 3 cm (top D x H) To make custard filling, whisk cream, sugar, yolks, milk and cornflour till smooth. Stir over medium-low heat till thick enough to coat pot thinly (or metal spoon if using non-stick pot). Place pot in water-bath. Add vanilla extract. Stir till mixture is half-cool. Leave to cool completely. Preheat oven to 250°C. Line baking tray with aluminium foil, shiny side up. When oven is ready, remove pastry shells from freezer. Place slightly apart on baking tray. Fill shells with custard to 5 mm from edge. Bake till crust is brown, and custard is burnt and just stops bubbling. This takes about 30-35 minutes. You should check every 10 minutes and rotate tray as necessary so that all tarts brown evenly. Remove tarts from oven to wire rack. Leave till cool. Serve within a few hours whilst pastry is crisp. Leftovers should be unmoulded before pastry softens, then refrigerated uncovered (make sure there isn't any funky odour in your fridge). Reheat tarts on foil lined baking tray at 200°C. Pastry would turn soggy after 5 minutes, then crisp up nicely after another 5 minutes or so. Custard would be creamy and smooth but a bit sunken.

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