Crudo in the finished squash sauce.
The first thing you taste in this crudo sauce is squash. Fresh, green squash sits on top, a cooked squash base holds the bottom, allium fills the middle, orange hangs in the background, and fresh pepper runs through the whole without heat. The sauce is sweet, acidic, saline and punchy in the way a good ponzu is punchy, and its acid brightens without tasting of lemon or lime. I built it from nine separate liquids, and every one of them exists because a particular aroma layer needed its own process. A single long extraction gave me the cooked squash base and nothing else. The other layers had to come from somewhere else, so I made each one as its own liquid and then seasoned the base liquid with liquid until the whole thing tasted like a crudo sauce. In this sauce the aroma decides the process: I worked out what each layer should smell and taste like first, then chose the process that could deliver it. The working method is a mixologist’s discipline applied to a crudo: every component exists as its own prepared liquid, and the sauce comes together by measured additions and tasting.
Pouring the squash crudo sauce alongside the crudo bites at the event.
The aroma map
Most crudo sauces lean on citrus. Guests expect lemon, lime or orange over a mild white fish, a few vegetables and maybe some chive, and the sauce delivers that expectation directly. I wanted squash to lead instead, which meant the citrus could not be the loudest thing in the bowl and the acid could not arrive as citrus juice. Once squash leads, the other parts of the sauce have to support it without crowding it.
When I tasted the finished sauce on October 29, the layers sat like this. The squash saline was the top note: green, gourd-like and cucumber-like, the flavor of raw squash. The long squash extraction was the base: cooked, vegetal and almost tea-like. The allium essence filled the middle notes with pungency. The orange essence sat in the background as a floral note I read as linalool, quiet enough that it never announced itself as citrus. The chile liquid disappeared into the whole as fresh pepper flavor. Across all of it, a citric and malic acid solution, a 2:1 sugar syrup and two salines set the taste: sweet, acidic, salty and punchy.
Each layer in that map has its own chemistry and its own weak point in the kitchen. Green squash notes fade with cooking. Allium changes from the moment you cut it. Orange aroma lives mostly in the peel and dissolves readily in oil. Chile heat sits mostly in the tissue around the seeds. Acid, sugar and salt change how you perceive each other and the aromas around them. So the sauce became five aromatic preparations plus four seasoning liquids, each made for its layer, and a base that carries them.
The squash extraction with the allium essence, squash saline, orange essence and 20% saline, labeled before assembly.
The base: a long, low-temperature squash extraction
The extraction bags coming out of the bath, labeled in at 17:00 on October 25 and out at 19:35 on October 26.
The base is kabocha squash held in water at 180°F for a little over a day: the bags went in at 17:00 on October 25 and came out at 19:35 the next evening. I removed the core, cut the squash into pieces that averaged 50 g, and packed 200 g of pieces into each of eight 120-micron filter bags, 1,600 g of squash in all. I split the filter bags between two larger extraction bags, four filter bags and 1,330 g of water in each, and set them in a water bath at 180°F, about 82°C. The filter bags let water reach every piece while keeping the solids together, so at the end I could lift the squash out and keep a strained liquid behind.
Kabocha pieces packed 200 g to a 120-micron filter bag, eight bags in all.
The extraction bags in the water bath, with two immersion circulators holding the temperature.
I chose water at 180°F over roasting on purpose. Roasting dries the squash surface and browns it, and that browning carries the burnt-sugar flavors people associate with roasted squash. Water at 180°F cannot dry the surface, so the squash cooks through and gives up its flavor to the water without a browned crust. When I tasted the extraction on October 27, it was surprisingly sweet, buttery up close, cooked-out and more vegetal than I expected, with an almost tea-like taste on the back end after I swallowed. The nose had a funky edge, though not a sulfurous one; it read as uniquely cooked squash. On its own and without salt, it was unremarkable. I would call it flat, and I mean that descriptively: it is a long-cooked squash with no caramelization, and that is exactly what it is.
The tea comparison has a reason behind it. When I have extracted basil, the leaf went from the spicy, aromatic herb everyone knows to something very close to tea. The squash moved the same way. In my experience, a long time in hot water takes a vegetable’s fresh aroma down and leaves a cooked, steeped, vegetal character, which is why I think “extraction” is the right word for this base.
Published work on cooked pumpkin describes the same direction. In a 2026 study of three pumpkin cultivars, Xue and colleagues found that boiling, steaming and baking all lowered the green and earthy aroma compounds that sit above their odor thresholds in raw pumpkin: 1-octen-3-ol, hexanal, (E)-2-hexenal, (E)-2-nonenal and (E,Z)-2,6-nonadienal. Steaming and boiling lowered them the most. Cooking also raised compounds with sweet, bread-like and spicy-smoky character, including furfural and 4-vinylguaiacol, and baking pushed furfural far higher than boiling did. A second 2026 study of thirteen Cucurbita maxima pumpkins found the same shift through a sensory panel: raw pumpkin smelled mainly green and cucumber-like, while steamed pumpkin smelled of chestnut, cream, sweetness and potato, with 2,3-butanedione and methional standing out as the drivers of the creamy, sweet and potato notes. Both studies cooked squash for minutes, and both describe the direction my day-long extraction took: green notes down, creamy and cooked notes up, browned notes kept low by keeping the squash wet. The buttery note I smelled up close belongs to that creamy family.
That chemistry sets the job for everything else in the sauce. The base supplies sweetness, body, the identity of cooked squash and a tea-like finish. It cannot supply the green top note, because the process that made it is the process that removes green notes. It also arrives without salt, acid or pungency. Every other liquid answers one of those gaps.
The top note: squash saline
The strained squash saline.
The fresh layer comes from raw squash, and raw winter squash is a flavor almost nobody tastes. You can eat zucchini raw, but the dense squashes that most American cooks buy for roasting are too fibrous to eat raw in any pleasant way. So the green, gourd-like, cucumber-like flavor of raw kabocha never makes it to the plate. The squash saline gets it there without the fiber.
I made it from the squash trimmings, peel and seeds included: 738 g of squash with 75 g of salt, 300 g of water and 30 g of sugar, vacuum-sealed on October 25 and refrigerated until I needed it four days later. Then I strained and pressed it through a 120-micron filter bag. My goals for it were salinity, sweetness, a floral character and the gourd and cucumber notes of raw squash. In the finished sauce it sat on the very top, the first thing I noticed after the squash itself, and to my taste it put back the fresh vegetable notes the long extraction had lost.
The chemistry runs opposite to the base. Cutting or crushing fresh plant tissue lets enzymes reach the fats in the cell membranes, and a lipoxygenase pathway turns those fats into short-chain green aldehydes. In cucumber, Spyropoulou and colleagues identified the enzymes that convert those aldehydes into (E)-2-hexenal and (E,Z)-2,6-nonadienal, two of the major flavor volatiles of cucumber. (E,Z)-2,6-nonadienal is one of the green compounds that Xue’s team measured in raw pumpkin and saw fall with cooking. Cutting makes the green notes; cooking takes them away. A raw saline keeps the cutting half of that story, and salt pulls the liquid out of the cut tissue and carries that raw flavor into something I can pour.
Salt also makes the saline a seasoning liquid. Every gram of squash saline adds salt to the sauce along with flavor, so it did the first part of the salting. I used all of it, 285 g in four additions, and when it ran out I finished the salt with a plain 20% saline. The full story of the saline, including what salt and sugar do to cut squash, is in Squash Saline: Raw Squash Flavor Without the Fiber.
The middle: allium essence
The allium essence blended, before straining.
The allium essence is the heavy hitter. I blended 400 g of onion, skin on, with 35 g of garlic cloves, skins on, and 700 g of water, then strained it through a 120-micron bag. Tasted on its own, within about ten minutes of blending, it was incredibly spicy, or more accurately zesty, with the kind of bite you get from biting into raw ginger. Once I stirred it into the squash base, it mellowed and gave the sauce a roasted impression it had not had before. Squash plus allium tasted like a liquid version of the cooked squash dishes an American cook might make, with the allium now soft and familiar.
The decision behind this liquid concerns the garnish. A crudo usually gets its allium from the top of the plate: fried garlic, fried onion or a scatter of fresh chive. I wanted the allium in the sauce itself, so the guest gets it in every spoonful whether or not a topping lands on that bite. The pungency of the essence gives the depth a fried garlic or fresh chive topping would. Toppings can still accentuate what the sauce already carries, but the sauce no longer depends on them, and the garnish is free to do another job.
The zest in the neat liquid comes from chemistry that cutting starts. Crushing garlic sets off an enzyme reaction that forms allicin and related thiosulfinates, sulfur compounds that give raw garlic its bite; Lawson and Hughes showed that the rate and products of that reaction depend on pH, time and temperature. Onion runs a related pathway with a twist: a second enzyme steers much of the reaction toward the tear-inducing lachrymatory factor, and when Eady and colleagues silenced that enzyme, onions made more thiosulfinates instead. Onion and garlic in one blender therefore give a mixed and moving sulfur profile, and Løkke and colleagues tracked the aroma of freshly cut onion changing over two hours.
Several things can soften that bite inside a sauce, and only some of them involve losing the pungent compounds. Dilution is the simplest: 340 g of essence went into roughly 3.6 kg of combined liquids, about one part in ten. The surrounding food can change the chemistry too: Lawson and Gardner mixed blended garlic into different condiments and found that what happened to its allicin depended strongly on the food. And perception can change without the chemistry changing: in an oil-containing garlic paste, Qiu and colleagues measured lower perceived pungency even as the oil slowed allicin loss. Any of these could be part of why the essence read mellow in the sauce. In practice, the lesson is to judge the allium at its use level, in the sauce, after each addition. I added 340 g in three portions, 81 g, 175 g and 84 g, and used only part of the stock. The allium essence article covers the preparation, the chemistry and the topping decision in depth.
The background: orange essence
The strained orange essence: 363 g, the whole batch.
The orange essence is there to sit behind the squash. I blended 31 g of Cara Cara orange peel, with the white pith removed, into 300 g of sunflower oil at maximum speed, then added 175 g of Cara Cara juice and blended again. I let it rest, pulled it under the vacuum machine’s maximum setting for 60 seconds, refrigerated it, and strained it through a 120-micron bag. All 363 g of the strained essence went into the base, the first liquid I added.
In the finished sauce the orange disappeared into the whole in the way I wanted. It was subservient to the allium and to the squash, a floral background note. Crudo sauces usually carry citrus up front because guests expect it. This sauce gets its acidity elsewhere, so the orange only has to add a background.
The preparation follows where orange aroma lives. The colored outer peel carries the orange’s aromatic oil, the spray you see when you bend a strip of zest, and blending that peel into oil first gives its aroma a fat to dissolve into. Li and colleagues tested vegetable oils as solvents for the aroma of dried basil and found refined sunflower oil performed best among the oils they compared. The juice goes in second and adds the orange’s juice character, its sweetness and sourness.
The orange molecule present in the largest amount does not decide how orange smells. When Högnadóttir and Rouseff analyzed a commercial orange essence oil, limonene made up 94.5% of the instrument signal, yet trained assessors sniffing the separated compounds found much smaller constituents among the most aroma-active. And the food around an aroma changes how much of it you need before you notice it: Plotto and colleagues measured the thresholds of key orange compounds in an orange-juice base and found them higher than in water, by amounts that varied from compound to compound. My sauce is a sweet, acidic, salty, squash-heavy liquid with allium in it, so the orange has plenty to compete with there, which suits a background note. The orange essence article goes deeper into the preparation and the chemistry.
Fresh pepper: a salted freeze–thaw chile liquid
The salted güero after freezing and thawing, liquid already drawn out into the bag.
I wanted fresh pepper flavor in the sauce without heat. The chile liquid started with 114 g of güero chile with the veins and seeds cut out. I salted it with 2.29 g of salt, about 2% of the chile’s weight, vacuum-sealed it at full pressure for 60 seconds and froze it. After thawing, I blended it and strained it through a 120-micron bag. The finished liquid tasted of fresh, vegetal pepper, and to me it had no heat at all. All 43 g went into the base, and in the finished sauce the chile sat baked into the whole as fresh pepper flavor.
The 43 g of chile liquid going into the squash extraction.
Trimming is the first control on heat. Capsaicinoids, the compounds behind a chile’s burn, concentrate in the placenta, the pale tissue that holds the seeds; Zamljen and colleagues found the placenta a major capsaicinoid reservoir across several species and cultivars, with large differences from fruit to fruit. Cutting it out removes the main reservoir. The walls can still hold some: Sugiyama found capsaicinoid-producing cells on the inner wall of the very hot Bhut Jolokia, and Hernández and colleagues measured capsaicinoids moving into brine from habanero slices that had already lost their seeds and placenta. So the mildness of this liquid reflects this chile and this trim, which is why I taste the trimmed chile before committing it. Freezing and salt open the walls. Ice crystals damage the cells; Schudel and colleagues froze sweet bell-pepper tissue, thawed it and measured the liquid that drained out, which depended on how they froze it. With its cells already broken, the chile gives up its watery, green flavor readily when I blend and strain. The chile article covers the preparation and the heat question in full.
Building the balance: acid, sugar and salt
Talking with guests at the event. One guest loved the dish and came back six times.
With the aromatic liquids in, the base tasted of its layers but not yet like a crudo sauce. When I eat a crudo I want something pungent like a ponzu: sweet, acidic, punchy and salty. The last four liquids build that taste.
The acid is a 5% solution of citric and malic acids, 2.5 g of each in 95 g of water. Lemon or lime juice would give the same kind of sourness, but it would also add lemon or lime flavor, and that would pull the sauce back toward the citrus profile I was avoiding. A clean acid solution brightens the squash without announcing a fruit. It also lets me add acid in exact small steps.
The sweetness comes from a 2:1 syrup, two parts sugar to one part water. Sweetness and sourness work against each other on the tongue. In a study of 259 Chinese and Danish consumers, sucrose suppressed the sourness of citric and tartaric acid solutions. Sugar can also lift aroma: Green and colleagues found that sucrose enhanced the retronasal odors they tested, while salt and citric acid did not do so consistently. And acid strength in the mouth depends on more than grams. Sowalsky and Noble showed that sourness rose with lower pH at the same acid concentration and with higher concentration at the same pH. In practice, I adjust acid and sugar together and taste them together, in small steps, because each addition changes how you read the last one.
The salt comes from the squash saline first and from a plain 20% saline (20 g of salt in 80 g of water) once the squash saline runs out. The extraction tasted unremarkable without salt, and I expected salt to lift it; in the finished sauce the salinity met the mark I wanted for a crudo.
The two salines, plain 20% and squash, stacked with the orange essence.
I seasoned in rounds over about 100 minutes. The photographs I took at each addition show acid going in 5 g at a time early on and 10 to 12 g later, syrup at 15 g and 16 g before larger additions of 41 to 100 g, and squash saline in four portions between them. By the end the sauce had taken 112 g of acid solution, 412 g of syrup, 285 g of squash saline and 45 g of standard saline. The acid solution carries about 5.6 g of acid and the syrup about 275 g of sugar, roughly 49 parts sugar to 1 part added acid by weight, which explains the sauce’s sweetness: this is a sweet crudo sauce, like a ponzu, and the acid keeps that sweetness bright. Because sucrose suppresses sourness, the brightness depends on the whole balance: the squash base, the orange juice in the essence and the salines all bring their own sweetness, acidity or salt, and I set the acid by taste against the whole base.
The squash extraction before seasoning.
The same base after seasoning, with all nine liquids in.
Texture
The finished sauce needed a little body to cling to the fish. I had two options. The spent squash from the extraction was watery and faint, with a washed-out, apple-like note, but its fiber had a good texture, and a few grams at a time could thicken the sauce. Larger amounts would have cost the sauce clarity and, worse, made it mushy against raw fish. I wanted the extraction to work as part of an ensemble, so I used a pre-hydrated xanthan stock instead.
For that batch I blended 2 g of xanthan gum into 100 g of water, held the mixture under maximum vacuum for 45 seconds to pull out air, and strained it through a fine mesh. I added 19 g of stock in seven additions of 2 to 5 g. That stock carries about 0.37 g of xanthan into the whole sauce, a very small amount added for a little cling. Thickeners can also change how aroma reaches the nose. In a mayonnaise study, van Eck and colleagues found that the higher-viscosity version released less limonene and tasted less lemony at the same fat level. Adding the stock in small steps, tasting after each, lets the sauce gain body without dulling the orange and allium.
What the finished sauce tastes like
Pouring the squash crudo sauce during service.
Squash leads. If someone asked what the flavor was, I would have to tell them squash, because the saline and the extraction together make the sauce squash-forward from top to bottom. It is squash vegetal and squash cooked. I hesitate to call it roasted, because roasted implies caramelization and there is none; it has no browned depth, and that is what it is. The roasted impression I noticed when the allium went in is an association, and moist heat can supply that kind of note on its own: Xue’s team found boiling and steaming raised 4-vinylguaiacol, a smoky, clove-like compound, in pumpkin. The allium gives it pungency and familiarity, the orange gives it a floral background, and the acid gives it brightness without lemon. It is fairly sweet, which suits a crudo and still depends on the fish and the chef’s taste.
Against the crudo targets I set, it met the expectation on salinity, acidity and sugar, and it is punchy. You could put it on a salad and it would be very good. What I want as a chef is for someone to taste it and say that this is a good crudo. The extraction, the separate liquids and the seasoning of liquids with liquids are for me and for other cooks who like that kind of thing. The guest only needs the bite to work.
Recipe and method
Squash Crudo Sauce
Ingredients
- 56 g squash extraction
- 10 g orange essence
- 9 g allium essence
- 3 g 5% citric–malic acid solution
- 11 g 2:1 simple syrup
- 8 g squash saline
- 1 g 20% standard saline
- 1 g chile freeze–thaw liquid
- 1 g pre-hydrated xanthan stock
Instructions
Assemble 100 g sauce
- Put 56 g strained squash extraction in a container large enough to stir.
- Add 10 g orange essence, then 1 g chile liquid. Stir before adding the remaining seasonings.
- Add 9 g allium essence, tasting as you go. The allium should fill the middle without covering the squash.
- Add 3 g acid solution, 11 g syrup and 8 g squash saline in portions, tasting as you go. The sauce should taste sweet, bright, salty and punchy while the squash leads.
- Stir in 1 g xanthan stock and check the cling. Add 1 g standard saline and taste.
Notes
The recipe is a set of preparations plus an assembly, built the way a bar builds from prepped components.
Prepared liquids lined up for assembly: allium essence, squash saline, orange essence and 20% saline.
Each preparation makes one layer. Prepare the components first, then measure the amounts below for 100 g of sauce. The produce-based preparations make larger batches; use the measured portions for the sauce. The sauce amounts use practical whole-gram proportions.
| Component | Amount |
|---|---|
| Squash extraction | 56 g |
| Orange essence | 10 g |
| Allium essence | 9 g |
| 5% citric–malic acid solution | 3 g |
| 2:1 simple syrup | 11 g |
| Squash saline | 8 g |
| 20% standard saline | 1 g |
| Chile freeze–thaw liquid | 1 g |
| Pre-hydrated xanthan stock | 1 g |
| Total | 100 g |
For my original batch, the squash extraction came to about 1,964 g by mass balance: 1,600 g of squash and 2,660 g of water, less 2,320 g of spent squash and wet filter bags, plus the 24 g of the eight dry bags. The combined liquids came to about 3,583 g before tasting losses. Strain every liquid except the xanthan stock through a 120-micron filter bag before it goes into the sauce.
Preparations
Squash extraction. Core 1,600 g of kabocha squash and cut it into pieces of about 50 g, so every piece cooks at the same rate. Pack 200 g of pieces into each of eight 120-micron filter bags; the bags keep the solids together and make straining simple. Put four filter bags and 1,330 g of water into each of two larger bags, and hold them in a 180°F (82°C) water bath for about 26 hours. Water at this temperature cooks the squash through without browning it. Lift out the filter bags and keep the liquid.
Squash saline. Combine 738 g of raw squash trimmings, including peel and seeds, with 75 g of salt, 300 g of water and 30 g of sugar. Vacuum-seal and refrigerate for several days; I held mine four. The salt draws liquid from the cut tissue, and the sugar adds sweetness. Strain and press through a 120-micron bag.
Allium essence. Blend 400 g of onion, skin on, with 35 g of garlic cloves, core removed and skins on, and 700 g of water. Strain through a 120-micron bag. Taste it neat soon after blending so you know its strength, then judge it again in the sauce.
Orange essence. Zest two Cara Cara oranges, leaving the pith behind. Blend 31 g of the peel with 300 g of sunflower oil at maximum speed. Add 175 g of Cara Cara juice and blend again. Rest, hold under maximum vacuum for 60 seconds, refrigerate, and strain through a 120-micron bag.
Chile liquid. Remove the veins and seeds from the güero chile and weigh 150 g of the trimmed flesh. Taste a piece for heat. Add 3 g of salt, vacuum-seal at full pressure for 60 seconds and freeze. Thaw, blend, and strain through a 120-micron bag.
Acid solution. Dissolve 2.5 g of L-malic acid and 2.5 g of anhydrous citric acid in 95 g of distilled water.
Simple syrup. Dissolve 67 g of sugar in 33 g of water for a rounded 2:1 syrup.
Standard saline. Dissolve 20 g of salt in 80 g of water.
Xanthan stock. Blend 2 g of xanthan gum into 98 g of water, hold under maximum vacuum for 45 seconds to remove air, and strain through a fine mesh.
Assembly
- Put 56 g of strained squash extraction in a container large enough to stir.
- Add 10 g of orange essence, then 1 g of chile liquid. Stir so their flavors join the base before the rest of the seasoning.
- Add 9 g of allium essence, tasting as you go. The allium should fill the middle without covering the squash.
- Add 3 g of acid solution, 11 g of syrup and 8 g of squash saline in portions, tasting as you go. The sauce should taste sweet, bright, salty and punchy while the squash leads.
- Stir in 1 g of xanthan stock and check the cling.
- Add 1 g of standard saline and taste the finished sauce.
The sister articles
Each layer in this sauce has its own article with the preparation, chemistry and decisions in more depth:
