A West Coast Mystery: The Butterscotch Tree, aka Jeffrey Pine

Jeffrey Pines
Jeffrey Pines | Source
Diacetyl
Diacetyl | Source

The aroma

We Californians have our very own arboreal enigma: the resin of the Jeffrey Pine. If you hug a large Jeffrey, and put your nose in a deep furrow in the bark, you will smell--believe it or not--butterscotch! What the dickens is in Jeffrey resin that makes it smell so yummy? Perhaps we can get a clue from butterscotch recipes.

If you want to make your own butterscotch from scratch, you'll need three ingredients for that distinctive butterscotch aroma: brown sugar, real butter, and vanilla. Of course, the molasses in the brown sugar is the primary contributor to the aroma. Real butter contributes the chemical diacetyl, and trace trace amounts of free butyric acid. (In higher concentrations, the latter has a very unpleasant smell.) And there are probably other chemical aroma contributors--of which I'm not aware--in the three basic ingredients.

There are some interesting coincidences in the varying olfactory perceptions of my fellow hikers.

I'm in a minority of hikers who smell butterscotch in Jeffrey resin. But most hikers smell vanilla. And vanilla is a key ingredient in butterscotch aroma.

A very small minority of hikers smell pineapple in Jeffrey resin. Interestingly, the butyric acid (in butter) is a moiety of the ethyl butyrate molecule, the essence of pineapple flavor.

Here's a link to Hubpages author DixieMockingbird's recipe for butterscotch filling.

Speaking of recipes... The hiker who smelled pineapple in the Jeffrey resin gave me an idea for a quickie dessert. How about butterscotch pudding with a pineapple slice? No, I have not tried it yet.

Does the Jeffrey Pine produce equivalent chemicals?

Or is there a single chemical in Jeffrey bark that hits all of these receptors in our noses? If so, it's possible that the surface of each region of the mystery molecule contributes a different aroma component, and that together, they all add up to butterscotch. That would be very interesting if true.

A second question: What is the survival value--if any--for the Jeffrey emissions? From my perspective, the Jeffrey Pine is sending out a very clear olfactory message: Eat me! Fortunately for the Jeffrey, Pine Bark Beetles don't have my finely honed olfactory sense.


The range of the Jeffrey Pine.
The range of the Jeffrey Pine. | Source
Jeffrey Pine trunk and bark.
Jeffrey Pine trunk and bark. | Source
Gentle Jeffrey cone
Gentle Jeffrey cone | Source

Jeffrey Pine trivia

As I mentioned earlier, Jeffrey Pines grow mainly in California. However there's supposed to be a very small Jeffrey zone near the SW corner of Oregon.

If you drive East on Highway 50 from the Sacramento metro area, you'll go mostly beyond the oak zone, and then you'll be up in the mixed conifer zone--including Jeffrey Pines--when you get above 5000 feet elevation (1500m).

The bark of the Jeffrey Pine has a dark reddish tinge. And a mature Jeffrey has deep furrows in between large plates.

The ranges of Jeffrey Pine and of the similar-appearing Ponderosa Pine overlap considerably. You can see both species near the Western shore of Lake Tahoe. How does a non-botanist (like yours truly) tell them apart?

According to a hiking friend, the most obvious difference is in the cones that you find under these pines. On Ponderosa cones, the sharp parts point out. On Jeffrey cones, the sharp parts point inward. Here's a memory aid: Prickly Ponderosa and Gentle Jeffrey.

In contrast with the Butterscotch Conundrum, there's a well-known piece of Jeffrey Pine chemistry. The resin contains a very high concentration of n-heptane. Petroleum also contains this hydrocarbon, mixed in with lots of other hydrocarbons. Apparently it's cheaper to extract high purity n-heptane from Jeffrey Pine resin than it is to do repeated fractional distillations from petrol.

N-heptane is useful for calibrations when you're researching octane ratings of various motor fuel formulations. N-heptane is such a poor motor fuel that it's assigned an arbitrary octane number of zero.

Speaking of n-heptane... The Wikipedia article on the Jeffrey Pine suggests--but does not explicitly state--that it's the heptane that contributes the butterscotch aroma to the resin. I'm very skeptical about that. N-heptane is a hydrocarbon skeleton without any meat on its bones. It does not contain any of the 'functional groups'--like the COOH carboxylic acid group--that make organic chemistry interesting.

But the Wikipedia article on n-heptane does not mention butterscotch or vanilla. So much for the inerrancy of Wikipedia. :)

Emerald Bay, Lake Tahoe.
Emerald Bay, Lake Tahoe. | Source
Tree-hugger Larry
Tree-hugger Larry | Source
Mountain Pine Beetle
Mountain Pine Beetle | Source

Speculation

So far, we know two things about Jeffrey Pine chemistry: the butterscotch aroma and the n-heptane. Let's put the two pieces of the puzzle together, and see if we can explain the question about survival value that I raised in the first section. Here's my wild hypothesis: Jeffrey Pine emissions are a means by which these trees communicate with each other.

A reasonable ratio of the butterscotch aroma in proportion to the n-heptane is a message to other Jeffrey Pines in the neighborhood:

Hello world! I'm a Jeffrey, and I'm in reasonably good health.

But if the proportion of butterscotch dips below a threshold value, the message becomes:

I'm a Jeffrey, and I'm under attack by Pine Bark Beetles. You'd better marshal your defenses immediately!

This is in addition to the generic role that jasmonic acid and its derivatives play in plant defenses. I'm guessing that the unique chemicals in Jeffrey resin are useful in defending against Pine Bark Beetles, and for 'alerting' other Jeffreys to the presence of these beasties.

Hey, hold your horses! Trees sending chemical messages? Yes, Hubpages author Nell Rose has written an outstanding article about the senses of trees and other plants. And some of these senses--together with plant pheromones--play a role in simple communication between plants.

By the way, my hypothesis is probably incorrect. I'm open to other ideas on the subject.

The main point is that there are reasons for the butterscotch aroma and for the n-heptane in Jeffrey resin. Proper scientific investigation could unlock the secrets of Jeffrey Pine chemistry.

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Comments 18 comments

Nell Rose profile image

Nell Rose 3 years ago from England

Hi Larry, fascinating stuff! I would never have known the difference between the different pines, and the chemicals in the Jeffrey tree are so interesting. I will put a link from this to mine if that's okay? voted up and shared! nell


Natashalh profile image

Natashalh 3 years ago from Hawaii

There's a tree that smells like butterscotch? Why didn't I move to California years ago? Butterscotch is one of those often neglected culinary greats. It's crazy this tree smells like butterscotch and it's not entirely clear why.


Larry Fields profile image

Larry Fields 3 years ago from Northern California Author

Hi Nell,

It's nice to hear from you, as always. And thanks for the share.


Larry Fields profile image

Larry Fields 3 years ago from Northern California Author

Hi Natashalh,

So you're a butterscotch aficionado too. Great minds think alike. Thanks for stopping by.


Jane Holmes 3 years ago

What a great hub! I enjoyed reading about the Butterscotch Pine and love your sense of humor!


Larry Fields profile image

Larry Fields 3 years ago from Northern California Author

Hi Jane. Thanks for stopping by.


alexadry profile image

alexadry 3 years ago from USA

I think I have to plan a trip to California as this tree is intriguing me. I am sure I would love to sniff it on a hike! Voted up and definitively interesting!


Larry Fields profile image

Larry Fields 3 years ago from Northern California Author

Hi alexadry,

Thanks for stopping by. If you, your husband, and your dogs plan to do a Jeffrey search in the Tahoe region, please let me know. There are a lot of Jeffreys near the lake itself--especially the SW shore.

I'm planning a Silver Fork hike for mid-June. In addition to Jeffreys and other conifers, it features white water (at that time of year), meadows, small granite domes, and gorgeous all-red Snow Plants. There are both medium and short versions of the hike.


moonlake profile image

moonlake 3 years ago from America

I have never heard of a Jeffrey Pine. Is it only the bark that smells of butterscotch or do the pinecones also smell the same? I had already planned to make butterscotch bars tomorrow when I saw your hub. Voted up and shared.


Larry Fields profile image

Larry Fields 3 years ago from Northern California Author

Hi moonlake,

Thanks for the vote of confidence.

To answer your question. The butterscotch fragrance mainly comes from the deep furrows in the bark of the larger Jeffreys. The smell from the smaller trees, which tend to have shallow furrows, is much less.


Whitney Rose Wood 21 months ago

I remember that scent! I always wondered where it came from. I would never have thought that it may be a tree's way of communicating against beetles. It makes sense though. Trees are pretty good at natural self-preservation! I am voting this up. I enjoyed reading this as the tone in your writing is as natural as the trees :)


Larry Fields profile image

Larry Fields 21 months ago from Northern California Author

Hi Whitney,

Thanks for stopping by, and for the vote. I'm glad that you liked the hub. I'm not certain about the anti-beetle communication; that's just a SWAG (scientific wild-assed guess). :)


Sniffing Weasel 17 months ago

My boy scouts gave me this nick name because of my habit of smelling these trees.

I am vaguely award of heptane used as a backpacking stove fuel. Hexane is also used as a fuel. I'm not saying either are as explosive as octane but either could be used as a fuel if oil prices increased enough and growing these trees became more efficient.

From the wikipedia article on Jeffrey pines:

Jeffrey pine wood is similar to ponderosa pine wood, and is used for the same purposes. The exceptional purity of n-heptane distilled from Jeffrey pine resin led to n-heptane being selected as the zero point on the octane rating scale of petrol.

As n-heptane is explosive when ignited, Jeffrey pine resin cannot be used to make turpentine. Before Jeffrey pine was distinguished from ponderosa pine as a distinct species in 1853, resin distillers operating in its range suffered a number of 'inexplicable' explosions during distillation, now known to have been caused by the unwitting use of Jeffrey pine resin.


Larry Fields profile image

Larry Fields 17 months ago from Northern California Author

Hi Sniffing Weasel. It's always nice to hear from a fellow tree-sniffer! Thanks for stopping by.

About explosiveness. So-called iso-octane is a much better motor fuel than n-heptane, because it is considerably less prone to premature detonation under the typical conditions in an internal combustion engine. 'Iso-octane' burns slower under these conditions,. It 'pings' less readily than n-heptane. The use of 'low-octane' fuels accelerates wear in modern internal combustion engines.


Erich A. 17 months ago

Walking on the Emerald Bay hike today and we did smell the butterscotch in the Jeffrey Pine, and not just maybe, all of us in my group could smell it.


Larry Fields profile image

Larry Fields 17 months ago from Northern California Author

Hi Erich A. The West shore of Lake Tahoe is a truly great place for Jeffrey Pine aficionados.

Were you hiking the Rubicon Trail, from DL Bliss State Park? In my opinion, this is THE premier Tahoe hike .

Thanks for stopping by.


Meeeeeeeeeeeeeeeee 6 months ago

We smelt the butterscotch smell on the Goat Trail and The Twin Falls hikes in Northern Arkansas, so..................


Larry Fields profile image

Larry Fields 2 months ago from Northern California Author

Hi Meeeeeeeeeeeeeeeee,

There is at least one other tree that smells a little like butterscotch. I was thinking of Ponderosa Pine. But Jeffrey Pine in Arkansas? Interesting. Supposedly, Jeffreys grow mainly in California. Thanks for stopping by.

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