controlling umami through temperature

I wrote about an umami-intensifying oven made by Hitachi over a year ago.  A recent web search shows no new information about this appliance being made available in the United States.  It pains me to know that after so much time (over a century now), we have not embraced this concept in our western world country.  So many of us frequent drive-thru's to get processed nourishment that food scientist lace with special ingredients to increase our satiation for certain flavors, yet we don't apply that technology to any sort of real food or real cuisine.  The science for pushing natural umami producing amino acids in food is already commonplace in other parts of the world, but not for us.  It's simply a matter of knowing what amino acids are inherent in the ingredients you are using, and then knowing what way to coax them out to the forefront of flavor.  Umami cravings are ancient in all of us.  They have directed our mouths to nourishment long before civilization ever existed... long before we had any reference as to what classified as food and what did not.  Those umami receptors are still very plentiful on our tongues, and knowing how to satisfy them can make good food into great food... if we only take the time to learn and accept umami as a taste sensation.  It's not just about MSG, so drop the old school stereotypes if you have them.  Umami (brought to us by glutamic acid, inosinic acid, and guanylic acid) is a natural component of many of the foods we eat on planet Earth.

Hope shines through!  At the March of Dimes event in Miami that we participated in recently, I was able to break away from our cocoa butter poached shrimp and our glass tower of basil bubbles to check out some of the other food.  There was the usual array of dishes common to these events.  My excitement peaked when I saw the booth for David Bouley's Evolution restaurant from the South Beach Ritz Carlton.  Chef Pierre explained the homemade tofu and dashi dish (similar to the one Bouley did at the ICC in New York) and how the kombu and bonito flakes were added and removed at different temperatures as the broth cooked.  This is similar to the traditional Japanese way that dashi broth is made.  In the classic method, the kombu is placed in cold water, and the fire brings the temp up to almost simmering (that happens around 180F), and the bonito flakes are dropped in.  Why?

Here are some facts to explain why this works.  Dashi broth is made of 2 main components (not including the water)...  kombu seaweed which is rich in glutamic acid and shaved bonito which is rich in inosinic acid.  Glutamate increases tremendously when cooked at temperatures below 80C (176F) and inosinic acid decreases tremendously at temperatures below 50C (122F).  This means that the seaweed and fish flakes are not happy at equal temperatures in the broth.  These temperatures are mapped out in the explaination of the Hitachi oven.

In essence, the kombu may be added in the initial heating.  The broth must never be brought above 80C.  The bonito should be added once the broth crosses the 50C point, which is right before simmering.  Bringing dashi up to a boil will either prevent umami from developing or destroy it.  That's why the Japanese do not boil the dashi.  By staying within the proper temperature ranges, the broth will be remarkably more savoury.  This is a traditional Japanese method.  Did the Japanese chefs who discovered this many years ago have access to amino acid measuring equipment to test the 'waters' of their broths, or did they just rely on their tongues and make interesting observations?  I vote for answer number 2.

Now if the concept being pushed at Bouley's restaurants spreads into American household kitchens, then maybe we can finally eventually buy an umami oven.  I still want one.  Kampai!