How to use freeze-dried herbs

THE ANSWER

Measure them 1:1 by volume with fresh chopped. A recipe asking for a tablespoon of chopped basil takes a level tablespoon from the jar — same spoon, same quantity, no conversion. The 1:3 rule you know for dried herbs, a teaspoon dried standing in for a tablespoon fresh, belongs to air-dried herbs. Apply it here and you have seasoned the dish at one third of what the recipe intended, tasted it, and concluded the jar was weak.

The difference is in the drying. Air-drying uses heat, and heat drives the volatile aromatic compounds out of the leaf while the cell walls collapse. Freeze-drying takes the ice straight to vapour under vacuum: no liquid phase, no heat, the cell structure holds, and the aromatics stay in the leaf. What is in the jar is the leaf minus its water. That is why it measures like the fresh one, and why it is still green.

Straight from the jar into anything wet. Nothing to soak, nothing to rehydrate first.

THE NUMBERS

Eight herbs, all $7.99.

Converting a recipe, in both directions

• The recipe says fresh chopped — measure the same volume from the jar. A tablespoon fresh is a tablespoon of ours.
• The recipe says dried — that recipe was written on the 1:3 rule, so convert back to fresh first. A teaspoon of dried means a tablespoon of fresh, so use a tablespoon of ours. Cross out the dried figure on the page and write the fresh one next to it, or you will make the same mistake again next month.

1% salt, which is the benchmark you are under

A finished sauce is seasoned at roughly 1% salt by weight: 500 g of sauce takes 5 g of salt. Home cooks routinely come in under half of that, taste a dish that is technically correct and sensorily dead, and conclude it needs more herb. It does not. It needs the other 2.5 g of salt.

Weigh it. A teaspoon of fine sea salt and a teaspoon of flaked salt are not the same quantity of salt, and every spoon measure for salt in print is wrong for one of them.

WHEN TO ADD

Two things set that table.

Fat carries aroma. Most herb aromatics are fat-soluble, which is why the same teaspoon of thyme tastes stronger in a butter sauce than in a water-based one, and why the first addition goes into the fat rather than into the liquid. Fat in the pan, herb into the fat, then the onion, then the liquid. Herb into the stock is a weaker version of the same dish.

Heat takes the top note. The volatile compounds freeze-drying protected are the same ones a long simmer drives off. A woody herb that went in at the start is still in the sauce at the end — it is just no longer the part of it you can smell.

THE METHOD

Read this as one pass through a pan. Sauce, braise, stew, ragù, tray of potatoes; the sequence is the same.

1. Weigh the salt for the whole dish before you start, into a small dish. Take from that dish at each stage below rather than from the box. This is the mechanical trick that makes the next instruction possible.
2. Season in layers, not once. Salt goes in at each stage — the aromatics, the liquid, the finish — so the seasoning is built through the dish instead of sitting on top of it. This is the single biggest difference between a restaurant sauce and a home one, and it costs nothing but the decision to do it. Acid works the same way: the wine or vinegar goes in early and cooks down, and a measured teaspoon goes in at the end — step 7.

One caveat, and it is the reason people get burned by layering: if the dish reduces hard, salt at the end. Water leaves, salt does not. Reduce by half and the seasoning you laid down at the start has doubled in concentration. Layer the salt in anything that simmers gently; hold it back in anything that reduces.

1. Fat in the pan. Woody herb, first addition, straight into it. Rosemary, thyme or sage before the onion, before the garlic, before anything else. Wait until you can smell it across the kitchen. If you cannot smell it, the pan is not hot enough yet, and the aroma is still in the leaf where it does you no good.
2. Garlic and red onion into warm fat, not a screaming pan. If the pan is ripping, pull it off the heat until the sizzling settles. The pieces are small and they carry sugar, so they colour far faster than a fresh clove does. They should sizzle and take colour. Never a dry pan — garlic straight into dry heat goes from pale to black while you are looking at something else, and the whole pan tastes of it.
3. Liquid in. Cook it out. Salt from the dish.
4. Off the heat, and the second addition goes in. The same woody herb you started with, again — this is the top note the first addition has already cooked off. Pan off the burner, herb in, stir, and leave it 2 minutes before it goes to the table. Any leafy herb — basil, parsley, cilantro — goes in at this point too, and only at this point. Residual heat brings them back. Watch the parsley: it goes in pale and comes back green, and when it stops changing colour it has taken up all the water it is going to.

Split the total the recipe calls for in half: half into the fat at step 3, half off the heat at step 6. In the sauces I write, a pan sauce for four takes 2 teaspoons of rosemary — 1 teaspoon and 1 teaspoon.

Two additions of one herb is not a chef's flourish. It is what happens at the pass — the station where every plate is tasted and adjusted in the last seconds before it leaves the kitchen. Salt, acid, and a final hit of the aromatic go in there, on every plate, which is why a restaurant sauce arrives smelling of the herb it was built on and a home one smells only of having been cooked.

Here is why this is worth doing at home with these particular jars rather than in theory: the second addition costs you nothing. No board, no knife, no second bunch bought for two teaspoons. The herb comes back in the time it takes to stir it through. When the second addition is free, you actually do it.

1. Taste. Then fix it in this order: salt, then acid. Salt to the 1% benchmark. Then, if it still tastes heavy, dull or muddy, it is short of acid, not short of salt — 1 teaspoon of lemon juice or wine vinegar into a sauce for four, stirred in and tasted again before you add any more. Acid lifts a sauce without making it taste sour, and this is the correction most home cooks never make.
2. Dry application? Bloom it first. A rub, a seasoned salt, a finishing sprinkle over roast potatoes, a compound butter. There is no water in any of those for the herb to take up, so it stays papery and tastes of very little. Stir it into oil or lemon juice — 1 tablespoon / 15 ml of oil per 1 tablespoon of herb — and leave it 2 to 3 minutes, until it has gone from crisp to soft and the smell has come up. Then it goes on the food.
3. Dry spoon into the jar, every time. Never a spoon that has been in the sauce, and never the open jar held over a steaming pan. There is nothing in there but the herb, and it will clump.

WHAT THEY WON'T DO

They are not a substitute for a fresh leaf where the leaf itself is the point.

No caprese. No whole basil over a pizza. No herb salad, no tabbouleh built on parsley as a green, no coriander sprigs on a bowl of noodles. A freeze-dried leaf has the flavour but not the structure: there is no water in it, so there is no bite, no snap and no gloss, and the moment it touches anything wet it softens. As a garnish carried by texture and appearance it will fail, and it will look like it failed.

Buy a bunch for those. Use the jar for everything you were going to cook the herb into, which is most of what anyone actually makes on a Tuesday.

WHAT GOES WRONG

You used a teaspoon where the recipe said a tablespoon. The 1:3 rule applied out of habit, and now the dish is seasoned at a third strength. Same volume as fresh chopped, every time.

The sauce is flat, so you added more herb. Almost always salt. Weigh the sauce, weigh the salt, aim at 1% — 5 g per 500 g. If it is properly salted and still tastes heavy or muddy, it is short of acid: 1 teaspoon of lemon juice or vinegar, stirred in, tasted.

It smells of nothing at the table. The herb went in once, at the start, and simmered for the whole cook. Everything the freeze-drying protected, the simmer took. Split the herb into two additions and put the second one in off the heat, 2 minutes before serving.

The garlic went black. Dry pan, high heat, garlic in first. Fat in the pan first, moderate heat, garlic after. If it is already black, start again — burnt garlic cannot be seasoned out.

The rub tasted of nothing. No water in a rub, so nothing rehydrated. Bloom it in oil for 2 to 3 minutes first.

WHAT TO MAKE WITH IT

A butter pan sauce for chicken or pork. Thyme into the butter at the start, deglaze, reduce, then the second teaspoon of thyme and the salt off the heat.

Tomato sauce that tastes cooked rather than assembled. Garlic and thyme into warm oil, tinned tomatoes, salt in layers, basil stirred in only after the pan comes off.

Roast potatoes with rosemary that you can smell. Half the rosemary into the fat before the potatoes go in the oven, half bloomed in 1 tablespoon / 15 ml of oil and tossed through the moment they come out.