Kitchen Project #43: Fig & whipped feta cheesecake

With a walnut oat crust aka my dream cheesecake!

Hello,

Welcome to today’s edition of Kitchen Projects, my recipe development newsletter. It’s so lovely to have you here. We are covering a LOT of ground today and I couldn’t be more excited about this recipe.

Over on KP+, I’ve shared all the details on perfecting caramelised nuts - a really useful technique that you’ll use forever. I launched KP+ earlier this year - subscribing is easy and only costs £5 a month. Over there I share lots of extra content, and when you subscribe, you help support the writing and research that goes into the newsletter:

Love
Nicola

Can you fig it?

Happy halloween everybody. Look: I’m not so good at themed bakes. So although today’s recipe isn’t exactly themed, it *might* appear a little bit spooky. Because, my friends, we are making a feta cheesecake, with figs, thyme and walnuts. Yes, it’s basically a winter salad transformed into a cheesecake. Freaked out? I understand, but bear with me for a min - the feta is there to add depth to the cheesecake, with its unmistakable saltiness and tang. It is divine. Trust me.

Some of the best cheesecakes I’ve ever had have utilised kind of stanky cheeses. One really memorable one (which is still available now) is the cheesecake from Cake & Bubbles, a champagne and pastry shop in Hotel Royal on Regent Street in London, is a particular stand out. Made of baron bigod brie, and a thin, hazelnut marzipan-esque ‘rind’, which perfectly balances the rich tang of the fatty cheese and is borderline savoury. The other standout cheesecake, for me, is the Honey & Co signature dessert - the brilliant kadaif, feta and honey cheesecake. It really is divine - ultra thick and rich, the ingredients are paddled together to achieve a dense, un-aerated texture. It is brilliant.

Today, I want to find a middleground between these two inspiring desserts. I want to build a cheesecake with an additional layer of flavour, a ‘can’t quite put your finger on it’ depth that unfolds as you eat it, but with the lightness of a mousse. 

You know I love a basque cheesecake, and one day I’m sure we’ll cover the glorious, but sometimes tempestuous, land of baked cheesecakes but today it’s all about the set. It has a couple of extra steps, but we’ll break it down together and you’ll be rewarded with a truly stunning dessert and you’ll deepen your baking science knowledge along the way.

How to set your cheesecake

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When it comes to set cheesecakes, there are a few options out there and I’m sure there are cheesecake purists that would argue they aren’t really cheesecakes at all. 

The first category is a simple mixture of whipped cream with sweetened cream cheese, poured onto a biscuit base and set. The second is the type uses gelatine, resulting in a more stable but mousse-like texture. Gelatine stabilised set cheesecakes are really popular in bakeries - we used to make a beautiful cheesecake at Dominique Ansel called the ‘Cotton Soft Cheesecake’ - it was an extraordinarily light, ricotta based mousse that was fortified with gelatine.

So, why do some cheesecakes use gelatine while others don’t? It’s all about the dairy and formulation.

Understanding fat

I know I go on a lot about the curse / luck of our dairy here in the UK, but understanding fat is essential to understand the structure of the desserts. 

Here, we’re so lucky to have dairy that is so high in fat that it is able to hold its shape very well when whipped, much better than cream from other countries that is lower in fat. To compare it for you, heavy cream in the US is around 36% fat and above, whilst double cream in the UK is around 48% fat. The higher the fat content, the more stable your foam is going to be. On the other hand, the more susceptible it is to turn into butter with too much agitation.

This is because cream - unlike oil - can whip without the help of emulsifiers (think about how you need egg yolks to whip oil into mayonnaise) because milk fat is its own stabiliser. As you whisk it,  the fat globules form a network trapping the air, and the more fat globules you have (ie the higher the fat%), the more stable it’ll be.

Although it’s possible to make your dairy proportionally ‘lower in fat’ by mixing in a little whole milk (as we do for a few recipes, including the strawberry shortcake and as I often do when whipping large quantities of cream so it doesn’t over whip), it’s unfortunately not possible to increase the fat content. 

So, in countries where dairy has lower fat content, gelatine is often essential in giving your creamy desserts body and texture, as it acts in the stabilising role that fat does.

Although fat is a great stabiliser for foams like whipped cream, it’s not perfect and it will degrade at room temperature eventually. This is too risky for professional environments, like afternoon teas or beautiful patisserie cabinets, so gelatine is also used as a bit of an insurance policy, since it sets really firm and holds the structure of desserts in place. Gelatine will not degrade or melt until around 35c, meaning it’s a pretty sure bet for longevity.

If you’re not sure how to check the fat content of your cream, take a look at the nutrition label - the (g) fat per 100g will tell you the %!

How to stabilise *without* gelatine

I prefer not to use gelatine unless it’s absolutely necessary since using it will exclude any vegetarians from sharing in the dessert. So today’s recipe is gelatine free. As well as using whipped cream to stabilise our set cheesecake, we’ll be looking to another major player for support.

Enter: Italian Meringue 

Amazingly, we’ve never actually covered Italian meringue on Kitchen Projects. It got an honourable mention in the HK Milk Tea Tres Leches Cake / Chiffon Cake recipe and in the parfait deep dive, but today we’ll get down to the nitty gritty.

Before we talk about Italian meringue specifically, here’s a reminder of how meringues work:

If you beat egg whites without sugar (aka a 1:0 ratio), a voluminous network of air-trapped-by-proteins will appear but it is prone to over beating (it’ll look kind of chunky). Once sugar is added, a stable chain of proteins will form and create the glossy stable mix that we all know and love.

So what makes Italian meringues special? Well, the egg whites are ‘cooked’, making it safe to eat and ultra stable. To make it, you mix together sugar and water to make a sugar syrup. This is then heated to 118c - 121c (more on that soon) and poured over foamy egg whites, with the whisk still running. The egg white/sugar syrup mixture is then whisked until the mixture is stiff and glossy.

The benefit of using an Italian meringue is that it is safe to eat at room temperature so is ideal for decorating/piping. As well as this, it’s extremely stable thanks to the cooked egg whites - the protein network is pretty much permanently set in place. Therefore it makes the perfect addition to a whipped cream foam, bolstering it’s holding power.

Unlike other meringues which can use lower ratios of sugar to egg white, the Italian meringue really benefits from at least 2:1 sugar to egg white ratio to give the most stable mixture. If you increase the sugar to a 2.5:1 ratio (as Erin Mcdowell does here), you’ll get an even stiffer and more stable mixture.

Italian meringues may seem difficult or too cheffy, what with the whole sugar syrup thing, but I promise they’re actually quite simple and very achievable. You may just need to make them a few times to take the edge off, promise! Here are a few things to look out for:

• Magic ratios

  Although you can play around with these as mentioned above, my go-to ratio for Italian Meringue is 3:2:1, Sugar : Egg whites : Water. So, you want double the sugar to egg whites. Then to make your sugar syrup, use half the quantity of water to sugar. When you mix your water and sugar, you want it to look like wet sand. If you add too much water by accident, don’t worry! It has ZERO impact on the final product, it will just take longer to climb past 100c

• The deal with crystallisation

  When you heat up sugar and water, there is a risk of crystallisation. This is when undissolved sugar crystals create a chain reaction in your syrup, where sugar molecules all stick together and become insoluble in the water. It doesn’t happen that often but when it does it's quite annoying and it is a pain to reverse - I usually just start again.
  
  The first way to prevent this is to simply mix your sugar and water in a calm way so sugar crystals don’t end up on the side of your pan - just mix it gently! You’ve probably seen tips asking you to ‘brush the edges of the pan with a wet pastry brush’ etc but you can skip all of th is fuss and just put a lid on the sugar syrup for the first minute or two. The trapped steam will run down the edges of the pan and dissolve any pesky bits of sugar. Easy.

• Eyes on your thermometer!
  
  The sugar temperature does matter so have your digital thermometer handy. Here’s a recap on sugar syrups from the parfait edition of KP. Pure water, as we know, cannot pass 100c as this is its boiling point. Once you mix in sugar, the boiling point changes and the temperature can climb way past this. The amount of water present will define how the sugar will behave in whatever recipe you’re using. This is why you can achieve different results by taking the sugar syrup to different temps. The more water you evaporate off, the thicker the syrup will become. You continue heating it and evaporating off the water until the concentration of water is so small (less than 1%) it becomes caramel!
  

• The foamyness of egg whites
  
  For best results, make sure the egg whites are only lightly foamy when you pour the syrup on. I usually start the mixer whisking on medium-high speed (around level 6 on the KitchenAid)  when the sugar syrup gets to about 112c. If your egg whites foam is already very developed and aerated when you pour the sugar syrups on, the sugar syrup doesn’t combine as well and you end up with a chunky / flabby meringue. It still aerates and may appear over whipped. You can still use it, it just won’t be glossy and smooth
  

• Turn the whisk speed down and pour slowly!

  If you pour your sugar syrup in too fast, some of the syrup can pool at the bottom of your KitchenAid. This happens to me all the time because I’m impatient! A little bit won’t make much of a difference but if you let too much pool then it will throw off the ratio. The best way to prevent this is to pour slowly, ensuring the syrup gets combined properly.
  
  As well as this, if the whisk is going too fast then it can splatter the syrup all over the edges of the KitchenAid bowl - this again can throw off the ratio, so turn the speed down a little bit and just dribble the syrup in gently, avoiding the moving whisk

All of the properties of Italian meringue make it the perfect backbone for our cheesecake today. As you need quite a lot of sugar to make an Italian meringue stable, the cheesecake will be solely sweetened by the meringue. 

The cheeses 

To make the base of this recipe, we need to blend our feta and cream cheese. Sounds simple enough, but this bit can actually go wrong quite easily.

When you food process feta, it first turns into a pile of cheesy rubble. In the Honey & Co recipe, Sarit Packer calls for ‘creamy feta’ and in this video, it seems to come out of a tin. I couldn’t find anything like this anywhere at short notice so I used the standard feta from Odysea.

After about 3 minutes of continuous processing, the crumbly cheese rubble will turn into a thick creamy mix, however you need to regularly scrape down the side of the food processor to reintroduce the cheese lumps. Mantra: No lumps left behind.

Next, you add in your full fat cream cheese. When it comes to cream cheese in the UK vs US, the roles are reversed: UK cream cheese is nowhere near as thick and lush as US cream cheese. In the US, it literally comes in blocks - it is so firm. It’s GLORIOUS. In the UK, our Philadelphia ain’t bad, but it is definitely more sensitive.

When I was making this recipe the other day, I popped the cream cheese into my blended feta and walked away. The food processor was churning away until suddenly… the sound changed into a wet smacking sound. I returned to the food processor and the cheese mix had liquified. Oops:

Smooth but NO body!

I continued on with the recipe and you know, it wasn’t bad. But the cheesecake was very fragile and not as stable at room temperature as I’d like. The only way around this is to simply watch it like a hawk - you only need to blend the cream cheese with the feta for around 30 seconds until its combined, no longer!

Adapting biscuit base

Ok guys, even though a biscuit base is often heralded as ‘the easiest pie crust EVER’ I’ve always struggled with them! Whether its too much butter, or not enough, I’ve often failed to get the proportion just right, especially if it’s a home made crumb.

Of course you can use digestive biscuits for today’s recipe if you like, but we’re incorporating additional flavour and texture by making our own biscuit crumbs and these are absolutely addicting: Walnut versions of my 3pm oat biscuits!

To adapt this recipe, I started by just removing half of the flour and replacing it with slightly chunky ground walnuts and using dark brown sugar, instead of light brown sugar. This was pretty good, but the biscuit was too oily - this makes sense because my chunky ground walnuts were not absorbing the butter. Since I’d also be mixing with MORE butter to make the crust, I made a few tweaks for the next round and reduced the butter by 20%. Success! Also, since this is going to be ground up, I did away with the half rubbed in/half melted method and simplified it to using all melted butter.

Because my hand made biscuits already have a fairly high proportion of butter, you need a relatively low percentage of butter to moisten the crumbs to set the crust. Plus, I hate a crumb crust that is too homogenous and claggy with butter - yucks! I still want to have the character of individual crumbs. Compared to a base made with digestive biscuits, which uses a 40% butter to biscuit crumb weight, we’re only using 10%-15% for ours today.

The reason I give you a range is because ingredients vary so much. The exact brand of oats I have may not be available where you are, or we may be using different brands of flour. All of these small details do matter, so the range takes this into account.

The question of whether you need to bake your base is really up to you: Since we bake our biscuits quite dark in the first instance, I don’t think it’s necessary to re-bake the crust - I simply mix my crumbs then stick in the freezer to chill whilst I prep my filling. I can understand if you’re using shop bought digestives that you might want to add some additional toasty flavours.

Minimising faff

One thing I really hate about making cheesecakes is the faff of moving them from place to place. De-moulding a set cheesecake and getting it off the base is basically my nightmare. So today we’ll be building our cheesecake directly onto the plate we’ll be serving it on - FAFF FREE! We will put a bit of paper on the base we can loosen and slide off so the base doesn’t totally stick to the plate, but that’s it. Easy!

Quick word on Figs

Figs are wonderful because they are basically already jam. A properly ripe fig is a total jewel. Although you can get them all year round, It’s fig time at the moment so go and enjoy them at the peak! In order to get the thyme and honey flavours to meld, I will be roasting a few figs but I’ll also be using fresh ones, so you get the whole spectrum of fig magic.

The crowning glory: Caramelised nuts

There was WAY too much to fit into one newsletter, so I’ll be sharing my method for caramelising the walnuts on KP+ - right here! Adding caramelised nuts is definitely an extra final flourish and adds a wonderful extra crunch for the cheesecake, but toasted walnuts would work well too.

Alright, let’s do this!

Whipped feta, fig and walnut dream cheesecake

This makes 1 x 8inch cheesecake

Walnut & oat biscuit

• 40g flaked oats

• 100g plain flour

• 90g ground walnuts

• 45g dark brown sugar

• ½ tsp bicarbonate of soda (2.5g)

• ¼ tsp maldon salt (around 2.6g)

• 1 tsp malt vinegar

• 120g butter, melted

Biscuit base

• 350g walnut oat biscuit crumbs

• 30g - 50g melted butter

Feta cheesecake mix

• 160g feta cheese (I use odysea brand)

• 160g full fat cream cheese (I use philadephia brand)

• 60g egg whites (around two)

• 120g sugar 

• 30g water

• 210g double cream

Roasted figs

• 2.5 figs

• 30g honey

• 3 sprigs of thyme

To finish

• 2.5 figs

• Honey to drizzle

• Thyme leaves to decorate

• Caramelised walnuts

Method - walnut oat crust

• Pre-heat oven to 170c fan

• Process the walnuts into a food processor - I like to leave a few chunky bits for flavour and texture

• Put walnuts, plain flour, bicarb, sugar and oats in a bowl and mix well

• Melt butter and pour into the bowl, and mix well

• Spread the biscuit dough onto a baking tray. Smooth it with your hands or with the help of a dough scraper

• Bake as one giant biscuit for 20 minutes

• Allow to cool then crumble up. I put it into a bag then crush by rolling over with a rolling pin several times. This biscuit is so crumbly, you won’t have to try very hard to break it up

• Melt the butter - mix the crumbs with the butter, bit by bit, until they look moist and you can get a clump of the crumbs to *just* hold together in your hands

  

• Cut a 9inch round of greaseproof paper and place onto your serving place. Place the 8inch springform tin (without the base) on the paper

• Press the crumb into the tin - the sides should be around 5cm tall, this amount of biscuit base does not cover the whole edge of the tin so don’t worry! I use a tall highball glass to help - don’t pack it in too much, as if the crust is too compressed its not as delicious!

  

• Set aside in the freezer or fridge until firm / whilst you prep the filling

Method - whipped feta mousse

• In a food processor, blitz the feta to crumbs and keep processing until its smooth, around 3 minutes. Make sure you scrape the cheese lumps into the mixture so it is homogenous

• Add in the cream cheese and process for about 30 seconds until it’s all combined. Set aside

• For the Italian meringue, dissolve the sugar into water so it resembles wet sand. Heat on a medium heat. To prevent crystallisation, put a lid on your pan for the first minute or so. Have a digital thermometer nearby

• When the sugar syrup reaches 112c, start whisking your egg whites on a medium high speed. They need to be foamy when you pour the syrup in

• When the sugar syrup reaches 118c, take it off the heat. You want your syrup to be in the range of 118c - 121c when it combines with the whites

• Turn the speed of the whisk down a little bit and drizzle the sugar syrup down the side of the bowl, ensuring its combined

• Turn the speed of your mixer back up and whisk until glossy stiff peaks form, around 8 minutes

• Meanwhile, whip the double cream to very soft peaks - you only want it to be *just* whipped (so the whisk is leaving trails and it just about holds itself up) as it will continue whipping as you fold everything together - my tip is always to stop just before you think its ready if possible

• Now it’s time to combine them all - stir a little of the italian meringue into the feta/cream cheese mix to lighten then fold together

• Now gently fold the feta/meringue mixture into the whipped cream - it will be ultra voluminous! I fold a small amount of cream into the cheese/meringue mixture then slowly add more as you go. I don’t like adding all the cream at once as there’s a risk you can overmix it. Just go bit by bit!
  
  You may need to fold it quite a lot to make sure there are no unmixed streaks - as its all the same colour - so just do your best

• Pour the cheesecake mixture into the crust and smooth with an offset spatula. Leave to set at least 4 hours

Method - Finishing

• Pre-heat oven to 200c fan

• Slice the figs into 0.5cm slices and lay onto a baking tray. Drizzle with honey and thyme then cover with another piece of paper. This will prevent the figs from going chewy as it lets them steam

• Bake for 15-20 mins - the figs should be jammy and soft

• Leave to cool completely before using, otherwise the watery liquid syrup might pool in the centre of your cheesecake. 

• To finish the cheesecake, remove the springform tin and slide the paper out from underneath

• Lay the roasted figs around the edge

• Cut the fresh figs into different sizes (approximately sixths) then place around the edge of the cheesecake 

• Finish with some fresh thyme, the caramelised walnuts and a drizzle of honey. A little sprinkle of salt works wonders too!

• Keeps well in the fridge for 3-4 days