Wednesday, December 16, 2020

Medlars, Australian Finger Limes, and Chinottos Oh My! Harvest Season is here!

Medlars embody the exotic and wonderful fruit time of Autumn! This year we are still processing (and picking) three of the fruits I had to grow myself just to have the opportunity to taste them.

Even in a year such as this one, the plants have managed to follow the flow of the seasons and do what they do so well - grow amazing fruits.

The Medlar


The Medlar is still a minor enigma to me - five hundred years ago in England this was one of the most popular Winter fruits. Admittedly, that is a pretty sparse competitive space, yet these mild flavored and strange to ripen fruits are a delight. The golden foliage of Autumn even looks wonderful on a murky, smokey day:

The enigma comes from my trying to adapt recipes for other fruits to the Medlar. It needs its own recipes, its is not an apple, nor a pear, nor a persimmon, all of which it has been compared to in some way or another. 

Medlars are picked when the leaves turn, while still essentially hard as rocks. My son eats them like this and enjoys them - I certainly can eat them like this, though they are much crunchier than I really prefer and the flavor has not fully developed.

Then, Medlars must be bletted. This is essentially over-ripening them until they are soft. Experimentally, I've determined this is hard to get the timing exactly right on, so instead of setting them on shelves in a single layer to slowly soften, I put them in a large pot, cover them with water, and bring to a simmer for about an hour until they are soft. 

At this point, skins need peeled off, and the soft pulp pushed through a strainer or collander to separate it from the large seeds in the center of the fruit. Collect the paste, and freeze it until you need it.

Australian Finger Limes

What is fantastic about the rainforests of Australia? Lots! In that list near the top, at least for me, is the Australian Finger Lime. It almost makes up for the very existence of things like Arboreal Leeches in the same forests...

Australian Finger Limes actually come in a wide range of fruit and juice sack colors, though I've only got one that is green (pink when very ripe). They also have kin in the area, like Blood Limes.

Something I did not appreciate when I planted these trees is exactly how spiny they are - picking the fruit is work, mostly because of the effort to deal with the long, sharp thorns these trees bear abundantly. Still, there is room to be creative, especially when my son helps invent prickle-free picking tools.

One problem I faced in previous years is a short harvest season starting around the beginning of October and only lasting through December. This year, we are experimenting with freezing whole finger limes. To use them, take them out of the freezer and allow them to thaw for about an hour. Then cut open and allow the juice sacks to come out just like in the fresh fruit. I wish I'd run across this idea a few years ago!

The Chinotto

This is how Switzerland lays claim to being a Citrus-growing nation! It is also part of the flavor of an Italian drink of the same name, and can be candied, juiced, or the rind grated into dishes to add a rather distinct flavor not too far from Oil of Bergamot.

This is a ridiculously slow growing tree. Ours is five feet tall and wide, and nearly twenty years old. Still, it bears glowing orange-yellow fruits on the ends of the branches, on display for many months, and holding well on the tree right through the Winter, snowfall and all.

I'll  be honest - aside from candied and as a really lovely bush for the Winter (and a spectacular source of Vitamin C), I don't really know what to do with these fruits yet. I feel there is more to them than I've yet coaxed from them. 

Now the rains have finally started, the next event will be Mushrooms!

Saturday, November 14, 2020

Kukumakranka - the wonderful edible fruits of Gethyllis bulbs

Kukumakranka - except the "K" letters represent clicks in the seemingly extinct Southern African language of the Koina people instead of the normal consonant sounds - besides being a name I cannot reliably accurately pronounce, names a group of bulbs, or rather their fruits. In botanical latin, the species below is Gethyllis verticillata.

My son describes the taste of this, the very first fresh fruit of this group I've managed to grow in California thus: "watery and tart, with a fruity fragrance". The fragrance of the fruit is intense and pleasant. To my spouse it is like "fruit cocktail in sweet syrup but with a slightly perfume-y strong strawberry component added to the flavor". 


The fruit has about the texture of a very ripe strawberry, with a lot of seeds that are soft and easily chewed - and which taste like the rest of the fruit.

A note about plant names - the useful part of the plant seems to most often be named first, then the rest of the plant gets that name applied, often with a nod to it denoting the rest of the plant rather than just the interesting bit. Examples are "Apple" and "Apple Tree", or "Walnut" and "Walnut Tree".

In rare cases, the plant has more than one amazing or useful bit - for example, the Oak Tree bears Acorns, not "oak tree nuts". In Hawaiian, the 'Ohia tree has the Lehua flowers.

In the case of Kukumakranka, the fruit is the bearer of the name, with the name of the plant or the bulb from which it arises seemingly lost.

These bulbs are from Winter rainfall/Summer dry deserts of South Africa, Botswana, and Namibia (with the exception of two species from the Summer rainfall areas of the Nama Karoo).

There are about 32 described species of Gethyllis. While many of them are rare, mostly due to being quite localized and/or habitat conversion, many remain abundant enough for the fruits to be made into brandy and show up in local markets when in season.

The flowering is day length triggered - flowers appear about one week after the longest day of the year. As these bulbs live in the ground, they must have some sort of clever strategy to keep aware of day length changes. (See light pipe leaves). The flowers push right out of the bare ground without any leaves. In fact, when in flower, only the flower is above ground. When in fruit, only the fruit is above ground, and when in leaf, only the leaves are above ground. At no point in the growth cycle do I get two of these at the same time!

  This is Gethyllis villosa, named for its hairy leaves.


Sunday, November 8, 2020

Hemihyalea edwardsii and and the Tanoaks

Around the first day of Fall, several things happen in a usual order. The Brunsvigia josephinae and B. littoralis flower, the Haemanthus coccineus flower, and the Edward's Glassywing moths appear on our front deck.

Arctiinae: Hemihyalea edwardsii


This year, the question is: how many more years will they grace our evening lights?

Edward's Glassywing moth is the adult phase of a woolybear caterpillar that eats Oak leaves. The deaths of massive numbers of oaks is one of several factors fueling, literally, the unprecedented fires in the Coast Ranges, including our Santa Cruz Mountains.

Our own oaks are in trouble. About one third of our Tanbark Oaks (Lithocarpus densiflorus) have died of Sudden Oak Death in the past year. The forest I fell in love with is fading into the past.

The area above our driveway is shown here - this is literally on the ridgeline of the Santa Cruz Mountains at around 2300'. 

Thursday, August 20, 2020

Our evolving wildfire story #CZULightningComplex

We are rushing to protect what we can. At present, we are not under any wildfire evacuation warnings or orders but we are taking things very seriously.

We safeguard rare and extinct species on our acreage.

The storms that unleashed the lightning and thunderstorms igniting over 360 wildfires in California are more common due to a warming climate. 

Please take a moment to consider how you can take direct action or provide monetary support to scientists and organizations working to understand and build a low carbon future for human civilization.

Thank you.

Donate to Puente Pescadero to support Coastside evacuees.

#CZULightningComplex #SaferatHome #globalpandemic #WildfireSafety #climatechange

Sunday, August 2, 2020

Plasma-Braised String Beans

We grow pole beans. Due to an invasion of cutworms (which of course are not actually worms, they are caterpillars that turn into moths), we have a lot fewer plants bearing beans than we intended. However, our son is very diligent in watching, watering, and harvesting the beans when they are ripe.

This has led to a dilemma - how to best prepare three individual string beans?

This time I didn't have something where we could just add them with the other vegetables - so I cut them to length and arranged them in a bowl in the microwave.

I gave them about 30 seconds expecting uneventful cooking. The loud sound and bright orange light that erupted almost immediately from the microwave put an early end to that exercise.

It turns out the beans had been cut into bits that were well separated - except where two had rolled back into each other. At that point, something like the grape in a microwave event developed (for a decent YouTube video go here, for an actual peer reviewed paper in the Proceedings of the National Academy of Sciences go here).

For the record, the beans were delicious. I'm suspecting that there was a bit more chemistry in the small burned areas where they were in contact than in a normal dry-braising cooking protocol, so I don't intend to make a habit of this particular method.

However, in my roughly half century, this is the first time I've cooked my food with ionized plasma as the primary thermal source... My son now wants the plant to grow even more beans so we can do this again...

Saturday, July 18, 2020

Bonsai Lightning!

We live in a residential space - there are limits to exactly what magnitude of lightning we can tolerate in the kitchen, after all. Why not make a dwarf kind of lightning?

I recently ran across a $9 miniature Tesla Coil kit. It seemed too good to be true, but it works (there were a few missing or helpful but absent parts: a nut for the screw to hold the transistor to the heat sink, and a hot glue gun really helps!).

This is not a link that generates any kickbacks or credits, I include it for those who are interested:

My son and I assembled the kit in about an hour (teaching the whole way, and making several repairs to self-inflicted damage to a few parts along the way). It worked on the first try when we were done, so I rate this as a decent design.

Key notes:

1. The secondary coil has a tendency to unwind - a drop of hot glue at each end of the winding saved a lot of rewinding time.

2. The high voltage end of the secondary (the little wire sticking up in air) is literally a tiny strand of copper wire. We hot glued it to a plastic drinking straw that we anchored on the inside of the coil to give it some stability.

3. Solder bridges are easy to make when soldering parts into the circuit board - especially if your assistant is enthusiastic with the solder.

4. Always solder in an area with good ventilation and wash hands after!

5. Put something underneath your soldering area that cannot catch fire - we used some fiberglass fabric (just the glass fabric!).

6. You need a 12V DC power supply that can provide at least 400ma of current, which they do mention but I repeat it here since we forgot.

My son says "The Tesla Coil is a complex circuit, but one of the easiest circuits to assemble. If your parent's say it is ok to build a Tesla Coil by Nikolai Tesla, fire up your soldering iron and get a 12 Volt power supply. Don't use a one-cell battery holder, since it does not work. When things don't work, it is not exciting. If you do have to happen to have a 12V power supply and everything you need in the kit, you can build it."

The lightning that is generated is small and at a very high frequency - the primary frequency of the oscillator appears to be around 200ns, or 5 MHz.

This is a frequency where the electricity will not penetrate deeply into human skin - however - lots of things can change that, so really no touching the high voltage end of the coil!

At 5MHz the skin depth is only about two micrometers, which is enough to be felt and cause pain - though the bigger danger is burns. There is enough power in the output to cause thermal burns from your skin heating up in the area of the spark, which is the more likely injury mode.

Also be aware that this device is a hazard to some electronics if they get too close - smart watches and cell phones come to mind.

Saturday, July 11, 2020

Why are there more lizards along trails in the late afternoon?

Recently we noticed that lizards are often much more abundant in the late afternoon actually on and along trails in the chaparral than in other areas. That brings up the question "Why?".

Turns out you just have to look at the trail the right way and it is obvious - though in this case, "the right way" is a literal type of camera reference - a thermographic camera. The photo above was taken with infrared light (or "IR" for short) between 7 and 14 microns in wavelength, instead of the more typical photos which use light roughly between 0.4 and 0.8 microns in wavelength.

The scene above might look more familiar in ordinary visible light (this isn't exactly the same spot, since the IR photo was taken just after sunset - it does show how the trail is flanked by vegetation and it is nearly the same spot).

Why use such odd light? Because it is the light that we humans give off, as well as pretty much anything else that is near "body temperature". Lizards are generally "cold blooded", which means that to get to their ideal comfort temperature, they have to move into warmer or cooler spots to adjust their temperature. In the heat of the day, they are looking for cooler spots - at least when it as hot as some parts of California get in summer...

Turns out their preferred body temperature is very close to ours (a bit cooler, not much though).

The trail remains warm as the day starts to cool off in the late afternoon and long into the evening. The lizards come to soak up the heat and be more comfortable.

Wait, "the light that humans give off"???

Yes, we all emit light. Lots of it, in fact. It is light that we cannot see with our eyes, but with other sensors we have - try holding the underside of your forearm facing someone else on a cool day and see if you can "feel" the infrared they emit from a few feet away. It is subtle, and most of us can notice it once we start looking. 

Planck's Law of Blackbody Radiation states that the amount of power emitted by and object effectively through thermal means (meaning atoms are vibrating and colliding, which causes the emission of photons at all wavelengths, very roughly) relates to the temperature of the object according to this relationship:

Three of the constants that define this universe are in the equation - I grabbed it from the Wikipedia page.

Astronomers, photographers, and interior decorators all know this to some degree, in the sense that a hotter star appears bluer than its cooler neighbors. "Red Dwarf" stars are cooler than our yellow sun, while Blue Giants are hotter. If you want a "warm" color of light, you go to cooler, redder equivalent filament temperatures (at least that was the case when light bulbs were actual bulbs with actual tungsten filaments...).

Let's look at what the equation above predicts for the light that our Sun gives off versus what we emit.

I had to put the green curve on a separate scale from the blue, red, and yellow curves since the power emitted by people as deep infrared light is really tiny compared to what the sun emits (the red or 5700 Kelvin curve).

The fact that we emit our own light is what makes thermal imaging possible. The slight differences between different areas of our bodies translate to significant changes in the power output by those areas.

I can literally call my son the "light of my life". Of course, that applies even more to the soup he is about to enjoy.... perhaps I should avoid working in the greeting card industry...

The soup is hotter in places than anything else in the photo, even though the "white hot" areas are just about 100 degrees Fahrenheit. His forehead and neck are hotter than his shirt or hair - so they give off more light. It just happens to be light that we cannot see with our eyes.