Cooking with dried herbs vs fresh herbs
Many chefs discovering authentic Australian ingredients for the first time ask me for fresh herbs rather than dried herbs; pure leaves rather than blends; and freshly picked fruits rather than frozen fruits.
In this blog, I’ll address just some of the issues of using dry herbs over fresh herbs and come back to the other questions in future blogs.
Firstly, some fresh herbs from the Old World are definitely superior when just picked to when they are dried, even if that drying is in subdued light, milling is at sub-chill temperatures and the product is stored at low temperature.
Basil, parsley, sage, mint or coriander and similar herb plants are botanically classed as herbs or forbs due to their growth forms: They are small plants with delicate, thin leaves which only need to be brushed to smell their highly volatile aromatic oils.
Other more twiggy herbs or those that grow on more robust plants such as thyme, rosemary and bay (a small tree) tend to be more able to retain their aromatics once dried. On a cellular level, the oil glands of these tougher leaves are buried deeper within the leaf or protected by waxy coats and drying does little to reduce the oil concentration. Milling these herb leaves once they are dry actually enhances delivery of the flavor principles.
The same can be said of Australian herbs.
Some, including river mint and sea parsley are better as fresh herbs than dried herbs. These are small plants, typically no more than 300mm high and have delicate leaves like their namesakes.
However, most of the Australian herbs which could be considered as more commercially significant come from the leaves of woody bushes (mintbush), small trees (mountain pepper), large eucalypt trees (peppermint gum, forestberry herb) and rainforest giants (lemon myrtle and aniseed myrtle). Trees are generally more adapted to cycles of wet and dry growing conditions while delicate herbs can only survive in conditions which are less variable. As a means of adapting to dry conditions, even in a rainforest where actual precipitation or surface run-off may be seasonally negligible, Australian aromatic leaved trees have evolved with the above protective advantages of deep tissue oils glands and/or waxy leaf coatings etc.
These herbs are best dried (in the dark), milled (to better deliver the flavour) and stored cool or frozen (to preserve the aromatics). Naturally, cooking methods are also important as high temperatures during deep frying or grilling, extended stewing or reducing and open flame cooking can also reduce the potency of flavors from essential oils.
What this means for chefs is that the Australian herb collection needs to be compared with relevant equivalent herbs from the Old World. The generally tough Australian herbs are better used dried and milled or the essential oils are left in the leaves rather than delivered to the diner. This makes them overly expensive as flavour yields can be only a few percent per herb added.
On the other hand, if discerning chefs;
1. start with quality ingredients and I refer readers to my previous blog on the benefits of using products including Lemon myrtle sprinkle, Alpine pepper, Fruit spice, Forest anise etc and not just their base herbs;
2. if they source the most brightly green herbs they can find (this reflects the care that the supplier has taken during post-harvest handling);
3. if they understand the nature of the particular herbs they are using; and
4. add sufficient herbs towards the end of cooking or trapping them in wraps, pastry, fillings, stuffings etc;
then the results will be impressive.
I have seen lemon myrtle, aniseed myrtle or even mountain pepper stewed for ages as sauces are reduced or flavours blended but the result is that the kitchen smells great for a while but the food ends up tasteless.
Alternatively, I have seen insufficient herbs added to dishes or attempts to flavour up a whole plate of sauced food rather than creating highlights and interest. Both generally end up in a lack of any discernable flavour – an underwhelming result.
As I said, comparing or understanding the similarities of Australian herbs to their Old World counterparts is the solution to these challenges. I hope that as authentic Australian ingredients grow in popularity and culinary colleges and cookbooks teach appropriate handling and usage of our herbs, there will be many more restaurants gaining patrons who refer their friends and acquaintances after enjoying the great tastes of Australia.