Hey {{first_name|there}},
Welcome to number four of open kitchen. You've seen the videos: someone pulls a container out of the fridge, shakes it, and the bone broth wobbles like jelly. If your stock doesn't jiggle, you're doing it wrong. And they're kinda right hahah. But almost nobody tells you what makes it jiggle, or why we even want that.
So this week we answer that, with the sauce where the jiggle matters most: demi-glace. It takes a whole day, so there's also a 45-minute version at the end that should literally be illegal.
What makes it jiggle
The jiggle is gelatin. It comes out of the collagen in bones, joints and skin when they cook for hours, and it's what gives a stock its body: silky when it's hot, set like jelly in the fridge. That sticky feeling on your lips after a good restaurant sauce is the same gelatin.
The official demi-glace is Escoffier's: brown stock and sauce espagnole (a brown sauce thickened with roux), reduced by half. Most kitchens dropped the flour because it dulls the flavour, so what we call demi-glace today is a brown stock reduced until its own gelatin makes it thick and glossy. Julia Child called that a "semi-demi-glace", honestly the best name in French cooking.
We're going with veal this week, but demi-glace is a way of cooking more than one recipe. You can make it with chicken, venison, duck, and you can mix: chicken feet in a beef stock works great.
Where the jiggle comes from
Young bones melt, old bones don't. In an animal that worked its whole life, the collagen gets cross-linked, like a rope twisted tighter and tighter. Heat softens it, but it never really melts. A calf's collagen turns into gelatin easily, and that's the whole reason it's veal and not beef.
Joints and feet are where it's at. Knuckles, a calf's foot or chicken feet carry way more collagen than a clean marrow bone. Ask your butcher to saw the knuckles in pieces, and get chicken feet at any Asian supermarket for almost nothing.
Bones go in the oven. Roasting gives flavour and colour, and the oven does it evenly, so skip the pan.
Why the tomato paste
Most people think a demi-glace turns brown because it simmers for eight hours. A big part of that colour is the tomato paste: in my experience one spoon more or less changes it more than a few extra hours. You see it best with chicken: a normal chicken stock is amber, the dark chicken stock restaurants use is the same stock with tomato paste.
Cook it first. Smear it on the bones for the last ten minutes in the oven, until it goes from bright red to rusty brown. I love raw tomato paste (I lick the spoon every time), but raw it's sharp and a bit bitter, cooked it turns sweet.
It's an umami bomb from the supermarket. Tomato paste is just concentrated tomatoes, and tomatoes are full of umami. Biggest life hack in your kitchen.
And no, your sauce won't taste like tomato soup. Herbs and spices taste like themselves, a lot of rosemary and you'll taste rosemary. Tomato, carrot and onion build depth instead: lots of ingredients with different notes that together make one big round flavour.
Why these vegetables
The classic, the way Escoffier would do it, is carrot, onion and celery, all in at the start.
Cut them big. For 6 to 8 hours you want mirepoix, pieces about half a thumb. Small pieces are overcooked after an hour and give off the wrong flavours, big ones release theirs slowly all day.
Leave the leek out. It's in most recipes, but after eight hours it turns bitter. Keep it for fish stocks and light chicken stocks.
Peel the carrots. In one of my first restaurants I threw unpeeled carrots in a stock, and my chef walked up: "There's two people in this world. People who peel carrots and people who don't. Which one do you wanna be?" I peeled every little piece I'd already cut hahah. Celery you can leave, it gets strained out anyway.
Halve the onion and garlic. Plenty of restaurants throw in a whole head of garlic cut in two, skin and all, and in 4 to 6 litres it won't turn garlicky. Clean skins are fine, roasted they even bring flavour.
Brown them for this one. For a deep demi-glace, roast or sauté the veg, every bit of colour is another layer. For a clear ramen broth they often go in raw.
Herbs and spices
Peppercorns, ideally toasted. In a Michelin kitchen they'll kill you for skipping that, at home after eight hours you'll barely notice. A bay leaf, for that classic bay leaf flavour nobody can describe. Then a bit of thyme, parsley stems and a little rosemary, and from there play with the season: more herby in winter (sage, tarragon, a lot of rosemary for venison), lighter in summer (lemon thyme). They don't need browning, they go straight in with the water.
My two extras
A bottle of wine. Not classic, just what I like: a whole bottle per 6 litres, right at the start. Red for depth with red meat or a port sauce, white for freshness and acidity. The alcohol cooks off, the flavour stays.
An apple. I picked this up in a restaurant two years ago and never stopped. It adds a soft sweetness and depth, and apples are full of pectin (the stuff that sets jam), which helps the sticky texture. Go easy, the sugar gets stronger as it reduces. A soft red one that isn't too sweet, like a Jonagold, works best, not a Granny Smith or Pink Lady.
Quick one. I'm putting everything I know into proper guides, small ones like 5 habits for better sauces, and bigger ones that go way deeper. Want them in your inbox before anyone on Instagram sees them? Tap a yes below. I'll only send them to the people who said yes, so nobody gets stuff they didn't ask for ;)
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Try it this week
Do the jiggle test: a few spoons of whatever stock you have (homemade, store-bought, last week's fish stock) in a glass in the fridge overnight. If it jiggles, it can become a sauce. If it pours, reducing alone won't get you one that coats. Now we know what's really in your freezer hahah.
Recipe of the week: the 45-minute demi-glace
I'm all for eight hours on the stove, but sometimes there's just no time, and this one has saved me more than once. All from the supermarket, no bones, no chicken feet.
Rank: home cook
Time: about 45 minutes
Makes: about 350 ml, a lot of sauces
What you need: your widest pot and a sieve
2 litres low-salt stock (I usually grab chicken, beef works too)
14 g gelatin powder (or about 6 sheets, weighed dry)
10 g tomato paste
10 ml soy sauce, low-salt if you can
optional: a splash of red wine or port, and any garlic, onion or herbs you have left
Sprinkle the gelatin over a few spoons of cold water (sheets: soak and squeeze). Brown the tomato paste in your widest pot, no oil, on medium heat, stirring until it smells sweet instead of sharp. Deglaze with the wine or port if you're using it, then pour in the stock, the gelatin and your extras. Turn it up high and reduce hard. Once about half is gone, taste and strain it for a clean sauce. Keep reducing until about 350 ml is left and it coats a spoon. Turn the heat low and stir in the soy at the very end, from here no hard boil (soy and heat, that's for another newsletter). Use it straight away or freeze it in an ice cube tray: two cubes is a pan sauce for two.
Why it works
Store-bought stock is mostly salt, flavour boosters and starch, with no depth and no body, so we add those back. Browned tomato paste brings colour, sweetness and umami, soy adds depth and a second layer of salt, and the gelatin gives back the body the bones would have given you.
The full-day version, and a lot more sauces built on it, are going into something I'm building for you guys. More on that soon ;)
Until next Wednesday
That's it for number four. Make the 45-minute one and send me a picture, or a video of your jiggle, I genuinely wanna see it. Questions about demi-glace or anything else? Just hit reply, I read everything myself.
See you next Wednesday ;)
P.S. Know someone who shakes their bone broth for the camera? Forward them this one, now they'll know why it jiggles. They can subscribe here so the next one lands in their inbox too.