British scientists provide the theme for Yan’s chicken curry pies – Turing, Darwin, Hawking and Crick. Much to Sandi’s delight she’s even developed an equation for the perfect pie to ensure the ideal ratio of filling to pastry. Unable to marinate the chicken for any length of time Yan comes up with another ingeniously scientific alternative and employs a vacuum sealer to suck the spices into the meat. Egg washing the inside of her pastry shells will, she propounds, protect them from the risk of sogginess.

As the judges tuck in, they agree Julia’s pies have too much paprika and they tell her they’re ‘disappointed’. Kate’s are ‘perfectly pleasant but a bit boring’ and her artistic efforts ‘don’t look good’ and have ‘lost definition’. Barely glazing over the appearance of a couple of soggy bottoms, Prue chides ‘I’ve seen you bake a lot better than this Kate’. Kate really doesn’t need to hear this.

Prue samples Stacey’s pies and decides ‘the combination of mince and pastry can be gluey’ but Paul is stuck on the robust filling and says it’s ‘like a proper northern pie’.

Paul says that Sophie’s quartet is ‘a triumph’ and he loves the classic dome shape of Liam’s bulging batch. Lacking the luxury of a thesaurus, Paul calls these ‘a triumph’ too. Prue adds ‘keep me a bit for lunch’.

Her taste buds are less tempted by the filling in Steven’s pies – there’s ‘something quite upsetting about eating pink mash’ she says, and Paul agrees it ‘looks like raw pork’. However it turns out to be a tasty success and he adds ‘berries with mash are the star of the show’. In an intense phone call between Mary Berry’s agent and her lawyer, the two excitedly debate if they can still claim royalties every time her name is mentioned. Reclining like Norma Desmond, La Berry sips at her gin and waits for the verdict.

Yan’s overambitious pies are judged to be unevenly baked and ‘a bit of a mess’. ‘Overcooked chicken’ is partly rescued by ‘delicious pastry’ and Yan tries to tip the balance in the latter’s favour by arguing that ‘it is pastry week’. ‘And filling as well, unfortunately,’ replies Paul.

For the technical, Paul sets the task of twelve Pastéis de nata (or Portuguese custard tarts) using rough puff pastry.

In Lisbon for the historical segment, Sandi discovers that local faithful folk crisped up their vestments and stiffened their wimples using egg whites as starch. I suspect it left them not only pretty pongy but also faced with a font full of yolks. Anyway after a failed enterprise producing Eggs St Benedict, they settled for the piety of pâtisserie.

Stacey and Liam roll their pastry lengthways and belatedly realise they’ll get fewer buttery layers. Yan flashes her tarts under the grill, Kate doesn’t need to – they’ve already picked up a chocolate brown hue in the oven. Julia’s disappointing batch puts her in danger, whilst Yan’s crisp cups and comely custard win with a comforting wobble.

Weighing up the winners and losers this week, Paul says ‘Kate’s been struggling the last few weeks – she’s just limping through week to week’. Oh dear Paul – have you been paying attention? Yes, poor Kate had a couple of tricky bakes but she didn’t exactly ‘limp’ into the Star Baker spot two weeks ago.

In series past, the savoury pies have been packed, stacked and even cranked like cogs, so it’s interesting to see us return to a simpler time when a ‘family-sized’ pie wasn’t welcome in the tent without a side order of fanfare. This week’s relatively straightforward showstopper is a hot water crust pie, hand-raised and topped with glazed fruit.

Kate and Liam are both warming up their hot water crusts with a little turmeric. She packs hers with potato and onion curry and a mango chilli glaze, whilst he recreates his nan Cynthia’s Sunday dinner of curried goat and fried plantain. There’s more mango partnering a little avocado for a cool salsa on top.

Traditionally shaped around a dolly (a wooden mould to the uninitiated) these bakers are adopting less orthodox approaches. Indeed there’s very little ‘raising’ as the crusts are rolled out over upturned cake tins and popped into the freezer to firm up. Yan and Julia stretch the brief even further by lining the inside of their tins, which seems less like a hand-raised pie and more like… a pie. Fortunately nobody actually pops out to buy a ready-made crust though there are clearly some lucrative commercial opportunities for the next series. ‘Your challenge this week is to make a delicious savoury pie using the Paul Hollywood™ traditional hand-raised pastry case, conveniently frozen for the busy baker and available from Iceland.’

Liam has second thoughts about shaping on the inside of his tin and chooses the more conventional crust forming. ‘My conscience kicked in’, he explains. Noel asks if Liam’s conscience has steely blue eyes and a silver grey beard. The old hairy conscience decides that Liam’s pie is ‘spectacular’.

The judges slice into Yan’s fruity bouquet of peaches, apricots and figs to reveal a meaty chequerboard of spiced sausage, black pudding, chorizo and chicken. They think it’s ‘quite stunning’ and ‘absolutely wonderful’.

Kate redeems herself with a great looking pie. Prue says the ‘flavour is good’ and Paul adds ‘I love that’.

Sophie’s game pie with forest fruits features venison, rabbit, wild boar and guinea fowl, with minced pork belly and mushroom duxelles packed in for good measure. It looks sumptuously rich and the judges praise the ‘great flavours’ but her ‘thick’ pastry walls are too substantial.

Favouring ‘a bit of camp’, Steven glazes his cranberries and rolls them in glitter. They top a Christmas-themed pie of turkey and pancetta, layered with Brussels sprouts and chestnuts. Sadly the flavours are not so sparkling – Prue calls it ‘a bit bland’ and Paul says it’s ‘a let down’. Julia’s asparagus, chicken, blue cheese and pear pie also fails to rise to the occasion as she manages to achieve overcooked filling and undercooked pastry.

It’s a race against time for Stacey as she battles to fill her softening pastry before it collapses. Rapidly spooning in lentil curry, eggs, spinach and cubes of paneer she candidly confides she’s worried about her ‘leaking crack’, then realises she’s also stuffed her crust with a circle of baking parchment intact. Confessing this to the judges, they extract the soggy paper and admit her effort ‘looks homemade’.

Good flavours just manage to save Stacey from a swift exit and it’s Julia whose time is sadly up. Beaming Liam phones home to proudly announce he’s Star Baker.

Next week Sandi promises us ‘the most demanding pastry showstopper the Bake Off has ever seen’. Firstly, one wonders why this didn’t feature as part of pastry week and secondly… well, it’s the kind of superlative statement that just gets on the wick of any graduates of the Bake Off tent. We’ve all had some pretty difficult challenges over the years. As for the most demanding ever? I think we’ll be the judge of that.