Garlic and onion for the allium essence.
Tasted on its own, within about ten minutes of blending, this onion and garlic liquid was incredibly spicy. Zesty is the better word: it had the agitated, sharp bite you get from biting straight into raw ginger. Then I stirred it into the squash base of my crudo sauce and it changed character. It mellowed, it gave the sauce a roasted impression, and squash plus allium suddenly tasted like a liquid version of the cooked squash dishes an American cook might make. The essence became the middle layer of the sauce, the pungent band between the cooked squash base and the fresh squash top note. That shift, and the decision to carry allium in the liquid instead of on top of the fish, come down to what cutting starts in onion and garlic and what the sauce does to it afterward.
Why the allium went into the liquid
A crudo usually gets its allium from the garnish. The expectation is a crispy topping of fried onion or fried garlic, or a green, vegetal topping like fresh chive. Those toppings work, but they tie the allium to whatever lands on a particular bite, and they lock the garnish into one job.
I wanted the allium in the sauce itself. The pungency of the essence gives the sauce the depth a fried garlic, fried onion or freshly chopped chive topping would give, so the guest gets allium in every spoonful. The toppings become optional. I can still use them to accentuate what the sauce already carries, but the sauce no longer depends on them, and the garnish is free to add texture, color or another flavor. The allium arrives in liquid form, already part of the bite.
What goes into the essence
The essence has three ingredients: onion, garlic and water. I weighed them straight into the blender jug: 400 g of onion with the skin on, its papery tunic intact, then 35 g of garlic cloves pulled from the head with the core removed and their skins left on, then 700 g of water. Then I blended them and strained the liquid through a 120-micron filter bag.
The onion going in with its tunic intact.
The garlic as it went in: cloves off the core, skins on.
The ratio puts onion in charge. There is more than eleven times as much onion as garlic by weight, and the water outweighs the onion and garlic together by about 1.6 to 1. Blending breaks the cells of both, and straining leaves a cloudy, pale liquid that carries what the water picked up and leaves the fiber behind. I add no salt to it; the sauce gets its salt from the salines.
The blended onion, garlic and water before straining.
What cutting starts
Onion and garlic build most of their pungency when you damage them. The bite comes from reactions that start when a knife or blade breaks the cells and lets an enzyme meet the sulfur-containing compounds stored in the tissue. The two alliums run that chemistry differently, which is why a blend of both behaves differently from either one.
In garlic, crushing sets off an enzyme reaction that forms allicin and related thiosulfinates, the sulfur compounds responsible for raw garlic’s sharp bite. The reaction does not run at one fixed speed. Lawson and Hughes followed thiosulfinate formation in garlic preparations and found that it depended on pH, time and temperature, with different thiosulfinates forming at different rates and low enough pH holding formation back.
Onion uses a related pathway with an extra branch. A second enzyme, lachrymatory-factor synthase, takes the reactive intermediate and turns much of it into the volatile compound that makes your eyes water. When Eady and colleagues silenced that enzyme in onion, the cut onions made more thiosulfinates instead, a sulfur profile closer to garlic’s. So when onion and garlic go into the same blender, I get two related reaction systems running side by side, each making its own mix of sulfur compounds.
The first minutes after blending
That mix keeps moving after the blade stops. Løkke and colleagues measured the volatiles released by freshly cut onion in real time over two hours. The early signals linked to the tear-inducing compound gave way to a different profile, with other sulfur compounds peaking later. The smell of cut onion keeps shifting through its first two hours.
I tasted my essence within about ten minutes of blending, early in that window, and that is the taste I described as zesty and ginger-like. That early tasting is useful as a calibration of how strong the essence is. To learn how it reads inside the sauce, I judge it again there.
Why it reads mellow in the sauce
In the sauce, the same essence read mellow and added a roasted impression. Several things can produce that change, and only some of them involve losing pungent compounds.
Dilution is the first. I added 340 g of essence to a sauce that came to roughly 3.6 kg of combined liquids, so the essence ended up at about one part in ten. A liquid that bites hard neat can sit comfortably at that level.
The surrounding food is the second. Lawson and Gardner blended fresh garlic with water, mixed the blend into several different condiments, refrigerated them, and tracked the garlic’s allicin over time. What happened depended strongly on the condiment: in one, allicin fell quickly as related disulfides rose, while others kept far more of it. The squash sauce is its own food, sweet, acidic and salty, with an oil-containing orange essence in it, and it can have its own effect on the allium chemistry.
Perception is the third. Pungency is something you feel, and the food around the compound changes how you feel it. Qiu and colleagues made a garlic paste with blended oil and found that it tasted less pungent and smelled less of garlic even as the oil slowed its allicin loss. Lower perceived bite and lower allicin are different things.
Concentration is a fourth factor, and it cuts both ways. Wang and colleagues found allicin more stable in more concentrated aqueous garlic extract, while Zhou and colleagues found that purified allicin broke down faster at higher concentration. The two systems differ, and together they say that you cannot predict how an allium liquid will hold up from its strength alone.
Any of these can contribute to the mellowing I tasted. The roasted impression is a sensory association: the combination of a distinctly cooked squash base and a suddenly mellow allium reads like cooked squash with onion and garlic, the way an American kitchen might prepare it. The practical rule follows directly. Judge the allium at its use level, in the sauce, after each addition.
Dosing it into the sauce
I added the essence in three portions: 81 g, 175 g and 84 g, 340 g in all. That used only part of the stock I made. The essence went in after the orange essence and the chile liquid, the quieter layers, and before the acid, syrup and saline rounds, so the seasoning that followed could account for its pungency.
The strained allium essence up close.
The target was the middle of the sauce. The squash had to stay in front, with the fresh squash saline on top and the cooked base underneath. The allium filled the space between them with pungency and familiarity. Three portions, 340 g, put it there, with stock left over.
The allium in the rest of the sauce
The allium went in before the seasoning, and everything that came after it changed how it reads. The acid rounds came next. Lawson and Hughes found that low enough pH holds back the formation of thiosulfinates in crushed garlic, but by the time the essence meets the citric–malic solution, blending has already set that reaction going in the blender jug. In the sauce, the acid shows up as brightness against the allium’s pungency.
The syrup rounds bring sweetness, and sweetness changes aroma as well as taste. Green and colleagues found that sucrose enhanced the retronasal odors they tested, the aromas you perceive from the back of the mouth while eating, while salt and citric acid did not do so consistently. The sauce took about 275 g of sugar through its syrup, so the allium sits in a sweet liquid, a setting that suits the cooked-squash association I tasted. Salt arrived through the squash saline between the acid and syrup rounds and from a plain saline at the end. A dose that tastes right before the acid and sugar go in can read differently after them, so taste for the allium again as the seasoning rounds go on.
Method
Allium Essence
Ingredients
- 400 g onion skin on
- 35 g garlic cloves pulled off the core, skins on
- 700 g water
Instructions
- Weigh 400 g onion, skin on, into a blender jug. Cut it into pieces small enough for the blender.
- Add 35 g garlic cloves, pulled off the core with their skins left on, and 700 g water. Blend until smooth.
- Strain through a 120-micron filter bag into a clean container.
- Taste a small amount neat soon after blending. Note how sharp it is and how long since you blended it.
Notes
- Weigh 400 g of onion, skin on, into a blender jug. Cut it into pieces small enough for the blender.
- Add 35 g of garlic cloves, pulled off the core with their skins left on.
- Add 700 g of water.
- Blend until smooth.
- Strain through a 120-micron filter bag into a clean container.
- Taste a small amount neat soon after blending. Note how sharp it is and how long since you blended it.
- For 100 g of squash crudo sauce, add 9 g of the essence to the base after the quieter aromatic liquids, tasting as you go. The allium should fill the middle without covering the main flavor.
The neat tasting tells you the strength of the batch you made today. The tasting in the sauce tells you how much to use.
Where it sits in the sauce
The allium essence is one of five aromatic liquids in the squash crudo sauce. The main sauce article explains how the layers fit together. The squash saline supplies the top note, the orange essence sits in the background, and the chile liquid adds fresh pepper flavor. The allium is the band in the middle that makes the squash taste familiar.
