Mfcttrf

What is the measurable difference between dry basil and fresh?

Is cooking with fresh herbs different than cooking with dry herbs?

In addition to the great answer by M.K: Most industrially dried and fresh herbs are not even of the same exact kind.

Taking basil as an example: Most basil species don't preserve their aroma well during the drying process. So while you can use any kind of basil for fresh use, you can maybe only use certain kinds for drying, because they preserve the aroma a little bit better. This will of course lead to a different flavor profile, because they are different kinds of basil.

You can basically divide herbs kind of into "hard" and "soft". "Hard" herbs would be something like rosemary and thyme, which are quite dry and hard, even when fresh. They preserve very well during the drying process and can be used almost identical fresh and dried. "Soft" herbs, on the other hand, wilt easily and many of them become almost tasteless during the drying process. This includes basil, chives, certain kinds of oregano, and to a certain extend parsley. For these herbs freezing is a better preserving method!

Fun fact: there are plants that only get fragrant when dried. Woodruff is a common example of that (although, no one would call that a herb as far as i know). It starts giving of its distinct flavor only when wilting.

Dry herbs in general last longer and have the "advantage" of better conservation. But they take more time to release their flavours, so you want to cook them earlier and for longer time (for example, adding dry oregano when you are cooking onions, later on adding the tomato sauce, as liquids will also help to release flavour).

With fresh herbs, you want to add them as lastly as possible to the dish. Check out this answer on dry herbs. For a pizza, for example, you want to add your fresh basil (or fresh herbs) right after its out of the oven, while the dry herbs, you want to add them while cooking the sauce or behind the tomato layer sauce, so they get all the flavour out and don't burn out.

IN TERMS OF MEASURING: Use less dried herbs than you would with fresh, because they are more concentrated when cooked.

If ⁠— by "measurable" ⁠— you are referring to a quantified chemical analysis, then sweet basil (Ocimum basilicum L) consists of 26 different compounds, of which terpenoids
linalool and 1,8-cineole make up the majority of them¹. I haven't seen any research data that specifically quantifies the impact of dehydration process on aroma profile, but this paper appears to quantify differences between various processing methods; I don't have a subscription to the journal myself and am unable to see the full text, but there may potentially be further data relevant to your inquiry.

If you mean quantifiable difference, the salient difference between fresh and dry basil is the amount (parts per million) of fragile, aromatic organic compounds (including some volatile organics; these are what you smell.) In basil (in the mint family), I distantly recall reading that those tasty chemicals are mainly terpenes. A chemist could quantify which ones using chromatography -- and even tell the difference between Italian and Thai basil(!) If you want more perhaps ask on Chemistry/biochemistry stacks?

Just to turn my rather frivolous comment into a bit of an answer...

Expanding on the soft vs hard herbs - basil has got to be one of the 'softest'.

Dried, you can barely tell you put any in the food. Fresh is so punchy it can transform any dish from average to wow.

Try a really simple Tricolore, or Caprese salad. It has only three ingredients, tomato, mozzarella & basil. Dress with a small amount of oil & vinegar [ideally balsamic but any will do at a push].

With fresh basil it's one of the most amazing salads you could make. With dried... it isn't.

^{pic from tablespoon.com}

The same for herbs like coriander [cilantro] & parsley.

4 tomatoes, one onion, chunk & drop in a bowl. Add a little oil & vinegar.

Then add either coriander or flat-leaf parsley for a taste explosion.

You can buy all these in supermarkets - growing in pots.

Keep the soil damp & put them on a sunny window-sill. Coriander & parsley you can keep a week or three that way, basically until you've used it up. Every stalk you cut means really the end of life for that stalk. It's theoretically possible to keep it growing, but in practice it's quite hard to achieve.

Basil, on the other hand, if you only ever cut just above the third leaf-pair down each stalk, you can keep it growing for years. I've got supermarket basil I've had for over 3 years now. If I can do it, anyone can.

well the most obvious easily measurable difference would be water content.