I was at my favorite Gelateria and asked one of the owners if she remembered someone. She looked at the photo on my phone and a big smile came to her face.
Oh! The thin one with the golden hair and the gold spoon. She always orders a pint and has all of it in shop with her gold spoon. You can tell the serious ones. They always bring their own gold spoons...
Jheri was partly to blame for my New York gelato quest. She loves the great gelateria of Italy and had made the comment that, except for a few shops in the city, American gelato was very good. That was excuse enough. I made a list of candidate shops from reviews and personal recommendations and had a nice excuse for a treat on most trips to the city. It started in May and by October a clear winner emerged.
Up until then I had not asked for Jheri's recommendation. Flavor is a complex synthesis of several senses making it even more interesting that both of us were in agreement. I was took back my phone and took a seat with my two flavors and thought about gold spoons.
Shops usually provide tiny plastic gelato spoons, but plastic colors the flavor a bit. Gelato purists bring their own spoons. Gold seems to be favored and that raises a few questions.
I had a taste of the questions as a kid. For whatever reason I licked the terminals of a nine volt battery. There is a mild electrical sensation along with a bitter taste. A wiser person would stay away from battery licking, but a twelve year old kid isn't exactly wise. I had to try it at different voltages and different parts of my tongue. Then I tried it along with apple slices to see if it modified the flavor.1 That led me to try tasting metals directly - copper, zinc, tin, steel, stainless steel and my mother's silver. Some of them had strong and disagreeable tastes. It was enough fun for a day - back then my attention wasn't different from Dug's in the movie Up! ...
Iron and steel corrodes in the presence of acid and would be a bad choice for anything acidic - tomato sauce or anything with citrus for example. Copper is used in in some pots and pans. It has a bitter taste, but copper pots and pans usually don't touch your tongue.
The battery gives hints of paths to explore. Metals like copper and zinc are reactive. They react with your saliva and electrons flow. You have made an inefficient battery and the current may be triggering the bitter taste. Stainless steel is very neutral but regular steel leaves a metallic taste.
Metals are so important that ages of civilization take their names - copper, bronze, and iron. They have a variety of useful properties that come from their internal structure. Metallurgy deserves its own post, but you have to go to the microscopic level to sort out what makes them special and see how they differ from each other. It seems odd, but their atoms form a crystalline lattice structure. These crystals are small and broken by dislocations which make metals malleable. It is possible to insert other atoms in the crystal lattices to form alloys which can have very different properties from pure metals. Metallurgy has produced an enormous variety of alloys making our much of our physical world possible.
Steels are iron based alloys. Until the last century creating good steels was something of a black art. The secrets of the fine steels used in swords - Damascus steel and Japanese samurai sword steel - were carefully guarded secrets and, in the case of Damascus, lost until recently. About a century ago metallurgists laboriously searched for better steels. Steels that would be better than the Titanic's that became brittle in icy water, better steels for gun barrels, and specialized steels for the emerging aircraft and automobile industries.
Just before WWI Harry Brearley was conducting such a search at a lab in Sheffield, England. He would make small batches changing the amounts of carbon, nickel, aluminum, chromium and other materials - a very slow and laborious process and not terribly different from what is done today. Quite by accident he found a piece from an old experiment that had been sitting around for some time. It was still shiny when any other steel alloy had started to rust. That shouldn't be. He checked his lab book and found this one had chromium and carbon added to the iron.
Initially the chromium seemed to be a mistake - the steel wasn't harder than good carbon steels so he had initially rejected it. But not rusting was special - even revolutionary. If you expose steel to air and water iron oxide - rust - forms. The trick is chromium reacts with oxygen before the iron gets a chance. It forms a tightly bound transparent layer of chromium oxide on the surface of the material. If you cut or break the material a new layer forms almost instantly - it is self-healing. He called the new steel stainless steel.
When you put a stainless steel spoon in your mouth you are tasting the chromium oxide layer which, compared to normal steel is, tasteless. Assuming you can form it into the appropriate shapes it is an excellent material for cutlery.
Gold is a nobel metal - supremely non-reactive. Some people say it makes some foods taste a bit sweeter, but that may be speculation. At the very least it is probably more neutral than other more reactive materials.
Only a few metals are found in their pure forms - copper, gold and iron. Early on pure iron came from meteorites and was the rarest of the three. Gold is common enough that it is found in many early civilizations, but rare enough to be used for objects of value (if evenly distributed each person currently alive would get a bit less than an ounce). It is soft and melts at comparatively low temperatures making it easy to work with. It alloys with silver. An 18 carat alloy is three quarters gold and is rugged enough for use in watches and jewelry.
Gold is easy to spot. Metals tend to reflect most of the visible light that strikes them. Aluminum, silver, platinum and many other metals absorb very little visible light giving them a silvery appearance. Gold preferentially absorbs light from the blue end of the spectrum making while leaving in the reds, oranges and yellows.2 Our brain processes this as a gold color.
Gold spoons aren't as difficult to own as you might think. While the real thing is far too expensive for most of us, gold plating only uses a few cents of the material and can be durable enough for light use. It would be fun to plate spoons with various metals and have a tasting party with various foods. You might end up abandoning silver as it tarnishes too easily giving it an unpleasant taste. Stainless steel would probably do quite well, but perhaps gold would dethrone it.
I'm nearing my time limit and it is clear something should be said about metals - their strength, malleability, ductility and electrical properties. The alloys, special metals like the supersteels in Colleen's bicycle frame and the transition of metallurgy from an art to a science. Even its sensual qualities. But for now I'll end noting a recent conversation about gold.
There was some speculation on how much gold will be used in the watch. A horologist said gold watches have between a tenth and three troy ounces of gold. The case rarely has over an ounce and is usually closer to a half ounce in fine watches. The alloy is usually 18 carat for durability. If the watch has a half ounce, you aren't going to see it for $1,000 and probably not even $2,000. Horace Dediu speculated the profit margin for the watches could easily be over 50% and I'd agree .. and at the high end it could be much more if conventional high quality watches are a guide.
What if the Apple's gold watch is successful? What if they sell several million in the Chinese market? How much would that impact the gold market? A million watches at fifteen grams each is fifteen metric tonnes. Demand is something like 2,000 tonnes for jewelry and 4,500 tonnes overall. It would take a lot of watches to make a serious dent.
Oh - and I now have a small gold plated spoon for gelato and other deserts.
1 My notebooks would have frightened my mother. I was the sort of kid who fooled around with electricity and can tell the difference between 110 and 220 VAC by touch. It got worse around the age of 14 or 15 with tesla coils and linear amplifiers for the radio transmitter.
2 Metals reflect equally across visible light because quantum mechanics doesn't allow photons to change an allowable energy level in the atom. Gold is special - the nucleus is so dense that relativistic effects come into play and the absorption of short wavelengths is allowed.
Copper also allows transitions, but for a different reason.
I've been away and haven't cooked anything notable since the last post. I did run across a fascinating piece by Hillary Rosner on the modern domestication of wild plants. It turns out we rely on fewer than 150 plants for food while about 50,000 are edible. The last major domestication of a plant took place about 3,000 years ago. There is great room for experimentation and some of this could turn out to be extremely important given the rapid climate change we are currently witness to.
I asked René Redzepi what culinary areas seemed ripe for exploration. Without a pause he said exploring the flavors of wild plants. He's doing some of that at NOMA, but he said the flavor palate was unimaginably large with the potential for fantastic discovery. In his mind we're too dependent on limited cuisines.