Comparing Bay Leaves

California Bay (left) and True Bay (right)

Living here in the San Francisco Bay area, I find that there is a lot of confusion about the difference between the leaves of our native “California Bay” (which many locals call “Bay Laurel”) and the leaves of true "Bay Laurel”. This isn’t an esoteric distinction, as each of these plants' leaves are used as culinary herbs. I was misinformed about them when I first moved here. Someone told me that the trees growing in the hills were “Bay trees” and that the leaves were great for cooking. Another friend said that they were the same plant from which we get “Bay leaves”, though they were more pungent than the ones grown around the Mediterranean - because of location, not species. Though I understood that gourmets prefer the more refined taste of Mediterranean bay leaves, it only made sense to use the abundantly available leaves of “bay” trees growing right here in the “Bay Area.”

It turns out that “Bay Laurel”, or “True Bay” - the Mediterranean tree from which we get the bay leaves that most people use for cooking - is actually Laurus nobilus. “California Bay” is Umbellularia californica. Both plants are in the same family, Lauraceae, but, as the Latin names show, they are not just different species, they come from different genuses. Being in the same family, it is not surprising that they share a number of physical features and their leaves include similar flavonoids that make them comparable in cooking - but they are not the same.

For the food chemists out there, the Journal of Agriculture and Food Chemistry (J. Agric. Food Chem. 2013, 61, 12283−12291) tells us that 1,8-cineol is the primary essential oil in Laurus nobilus. Laurus nobilis contains 57% of this compound, but it makes up only 20% of the essential oil in U. californica. Conversely, Umbellulone is 37% of the essential oil in U. californica, but it isn’t found in L. nobilis at all. Methyleugenol, thymol, and α-terpineol make up 8.4%, 7.8%, and 6.5% of U. californica but are mostly or entirely missing from oil of L. nobilis. There are many other differences in the composition of oil extracted from leaves of these two plants. I have reformatted the table from the JAFC article and provided it for your enjoyment at the bottom of this post.

What’s really important for Californian cooks is the awareness that these are different plants with different flavors. Both leaves are equally edible and both can be used in cooking, but substituting one for the other could produce different results. You can think of it like using Italian basil in place of Thai basil, or, possibly, like replacing lime juice with lemon. If the ingredient is a minor element in a recipe, the results might be indistinguishable. But, if it is a key component of a dish, substitution could create a very different taste.

Though L. nobilus is not native to the area, it grows very well in our Mediterranean climate, so one might run into both of these trees. If you're not up to the task of nibbling on a leaf and saying "ahhh, yes, I definitely sense 8.4% methyleugenol", how do you tell them apart? Here are some of the major physical differences between their leaves.

The photo on the left shows the tops of the leaves, the image on the right is of the undersides. In each picture, a leaf of Umbellularia californica is on left and Laurus nobilus is on right

The leaves of Laurus nobilus:

• Wider than Umbellularia californica
• Pointier
• Deeper green
• Have a slightly wavy edge
• Thicker and more brittle than those of U. californica

Umbellularia californica leaves:

• Narrower than those of Laurus nobilus
• Have rounded tips
• Are lighter green
• Have a smooth edge
• Are thinner, softer, more supple, and more readily bent than those of L. nobilus.

[Note: These differences apply to mature leaves. The young leaves of both trees are light green and soft, making them much harder to distinguish.]

Umbellularia californica in bloom

Umbellularia californica bearing fruit

Umbellularia californica fruit and nut

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The following table lists the compounds found in L. nobilus and U. californica. It is from from The Journal of Agriculture and Food Chemistry. It has been edited for format, not content.

Compound	RRI-a	RRI-b	U. cal %	L. nobilius %	ID method
α-pinene	1032	939	0.1	3.8	tR,MS
α-thujene	1035			0.4	tR,MS
β-pinene	1118	979	0.1	3.6	tR,MS
sabinene	1132	975	0.1	5.7	tR,MS
myrcene	1174	991	0.2		tR,MS
α-terpinene	1188	1017	0.2	0.2	tR,MS
dehydro-1,8-cineole	1195			0.9	MS
limonene	1203	1029	0.1	1	tR,MS
1,8-cineole	1213	1031	19.5	57.4	tR,NMR,MS
γ-terpinene	1255	1060	0.3	0.3	tR,MS
p-cymene	1280	1025	2.1	2.2	tR,MS
terpinolene	1290	1089	0.1	0.1	tR,MS
α,p-dimethylstyrene	1452		0.1		MS
trans-sabinene hydrate	1474	1098	0.1	0.6	MS
camphor	1532		0.2		tR,MS
linalool	1553	1097	0.4	0.3	tR,MS
cis-sabinene hydrate	1556	1070	0.1	0.6	MS
trans-p-menth-2-en-1-ol	1571	0.1	0.2		MS
pinocarvone	1586			0.3	tR,MS
bornyl acetate	1591			0.2	tR,MS
terpinen-4-ol	1611	1177	6.6	4	tR,MS
cis-p-menth-2-en-1-ol	1638		0.1		MS
trans-p-mentha-2,8-dien-1-ol	1639			0.5	MS
thuj-3-en-10-al	1642			0.5	MS
myrtenal	1648			0.8	MS
umbellulone	1657	1171	36.7		tR,NMR,MS
trans-pinocarveol	1670			0.5	tR,MS
δ-terpineol	1682	0.6		0.9	MS
α-terpineol	1706	1189	6.5	3.8	tR,MS
α-terpinyl acetate	1709			7	tR,MS
borneol	1719		0.1		tR,MS
β-bisabolene	1741	1506	2.2		MS
phellandral	1744		0.1	0.4	MS
(E)-α-bisabolene	1784		0.5		MS
ar-curcumene	1786		0.1		MS
myrtenol	1804			0.3	tR,MS
nerol	1808		0.1		tR,MS
trans-p-mentha-1(7),8-dien-2-ol	1811			0.3	MS
p-mentha-1,5-dien-7-ol	1814			0.2	MS
2-tridecanone	1815		0.1		MS
trans-carveol	1845			0.1	tR,MS
p-cymen-8-ol	1864		0.2	0.2	tR,MS
cis-p-mentha-1(7),8-diene-2-ol	1896			0.3	MS
cuminyl acetate	1981		0.1		tR,MS
caryophyllene oxide	2008	1583	< 0.1%	0.1	tR,MS
methyleugenol	2030	1404	8.4	0.9	tR,MS
(E)-nerolidol	2050	1563	0.3		tR,MS
p-mentha-1,4-dien-7-ol	2073		0.3		MS
elemol	2096	1550	0.4		MS
cumin alcohol	2113		0.5	0.1	tR,MS
cis-p-menth-3-en-1,2-diol	2184		< 0.1%		MS
eugenol	2186	1359	0.4	0.1	tR,MS
γ-eudesmol	2185		0.2		MS
thymol	2198	1290	7.8		tR,MS
carvacrol	2239	1299	< 0.1%		tR,MS
elemicine	2245	1557	0.1		MS
α-eudesmol	2250	1654	0.1		MS
β-eudesmol	2257	1651	0.2	0.3	MS
chavicol	2353		0.2		MS
dodecanoic acid	2503		0.3		tR,MS
hexadecanoic acid	2931		0.1		tR,MS

RRI-a: relative retention indices calculated against n-alkanes on polar column.
RRI-b: relative retention indices calculated against n-alkanes on apolar column (Adams, 2001).

U Cal %: % of compound found in Umbellularia californica.
L. Nobilius %, % of compound found in Laurus nobilius

[each of these % calculated from FID data for polar column]

Identification method: tR, identification based on the retention times (tR) of genuine compounds on the HP Innowax column; MS, identified on the basis of computer matching of the mass spectra with those of the Wiley and MassFinder libraries and comparison with literature data.  NMR spectra were recorded on American Varian Mercury plus 400 NMR spectrometers.

Are we not our memories?

Five or six years ago my neighbor Bill suffered a very unusual stroke. The stroke destroyed his ability to form new memories. I am told that this is extremely rare. I don’t know how long he is able to remember anything, but it appears to be no more than a couple of minutes. Interacting with Bill is very strange.

A while back Bill visited with me for a couple of hours. At the time I did not know about his condition. It was disconcerting as Bill told me the same stories from his life over and over again. He told me about the salon where he works (or, as I later learned, "worked") as a hairdresser. As soon as he finished describing the salon, he started over again telling me about the salon and his job. He told me about his kids, then about the salon, then about his kids, then about his first wife, then his kids, then the salon, then the salon again, then his first wife again… and on and on. On the first couple of repetitions I was completely confused. I wasn’t sure if he was repeating himself for emphasis, or if it was some sort of a peculiar joke, or the world’s worst case of egotism. Eventually I realized that there was some pathology involved. It was later that I learned from another neighbor about Bill’s stroke.

On another occasion I was in my garden when Bill came up and asked if he could use my phone. He told me that his car was at the local gas station being repaired. He wanted to call them to ask when his car would be ready, but his phone wasn't working. Of course I invited him in to use the phone. He called a number that he had written down on a piece of paper, but the number was wrong – God knows how old the piece of paper may have been or what that phone number really was. I helped him look up the correct number for the nearby gas station. When we reached them, they told him that his car had been done and delivered the day before. They said he would find his car in his garage. Fortunately they must have been aware of Bill's condition, so they took it in stride. I wondered how Bill remembered having his car serviced at all, or if he brought his car to them years earlier and now calls them every day to check on its status. After hanging up the phone, Bill thanked me and went home. I watched him walk back towards his house desperately hoping that he would forget about his car completely. I would hate to think of him trying to drive.

I see Bill walking around my neighborhood several times a day with a care-giver. Sometimes they are walking side-by-side chatting, sometimes the care-giver is trailing behind. Every time I see Bill I have the peculiar experience of deciding whether or not I feel like bothering to interact with him. After all, we’ll just have the same conversations over again, and he won’t remember that we’ve ever met. I could be nice to him, or I could call him insulting names, or I could just walk right past as though he was a total stranger. As far as Bill is concerned, a minute later it would make no difference.

The other day I was walking my dog when I ran into Bill. I said, “Hi Bill, how are you doing?” Of course he didn’t recognize me, so I introduced myself and pointed out that I lived in the house around the corner. We talked a bit.

I said to him, “Wow, Bill. You really do walk a lot. I see you walking around the block all the time.”

“No, you must be mistaken,” he replied, “I only walk once in the morning and once in the evening.”

Of course it was he who was mistaken. He just didn’t remember that he does his morning walk three or four times, and his evening walk three or four times.

As strange as it is to experience Bill from the outside, I can’t begin to imagine what it would be like to be Bill. What must it be like to wake up each morning and look in the mirror to discover that you are much older than you thought? How shocking it must be to brush your teeth, shower, shave, and dress to get ready for work, then learn that you haven’t worked for years. I can’t imagine the conversation that must ensue each day as a total stranger enters Bill’s home and explains that he is the care-giver, that he has been taking care of Bill for years, and that the last half decade of his life is effectively gone.

What are we if not our memories? Bill has all of his memories from before the stroke. He seems quite happy and he is in excellent health (no doubt from all the walking.) He joyfully recalls his memories from the first 60-some years of his life. But, from a purely philosophical standpoint, I find myself wondering what it means to be alive if you cannot create new memories? In some abstract sense, is Bill alive?

This is the strange imponderable that I am pondering this morning. I have no idea what it means. If I should happen to come up with an answer, I can only hope that I remember it.

Elderflower Syrup

Sambucus canadensis 'Wyldewood 1'

When I was planning my garden a few years ago, I decided that I wanted to have elderberries. I found a study done by the University of Missouri which concluded that the most fruitful variety of elderberry was a tree named 'Wyldewood 1'. It turns out that the only place to get them is from Wyldewood Cellars in Kansas. At the time, they were not prepared to ship plants to California. After some work learning about the requirements of the California Dept. of Agriculture and several hours on the phone, I was able to convince them to go through the process of having one of their trees inspected and sent to me. Thus, I became the first owner of a Sambucus Canadensis 'Wyldewood 1' in California. Over the years it has grown to become a fine specimen.

Last year when the tree was in full bloom I invited my friend Sean to join me in making elderflower liqueur. I picked a bucket of the most fragrant flowers, then Sean and I each spent an hour snipping the tiny flowers from the flower heads for our batches of liqueur.

We were working from a recipe that we found online at honest-food.net. It indicated that we should infuse Everclear or vodka with the elderflowers for “…at least a few days…” but, the author noted “I typically hold mine for two weeks, although I used to do a month.” After infusion, one strains the liquid and adds simple syrup. Sean took his jar of vodka and flowers home, and I put mine in my root cellar to rest. After two weeks I opened my mason jar and strained it. Not sure how sweet I wanted it, I experimented with small samples, varying the amount of simple syrup. The results were mediocre at best. No amount of variation in sweetness made a product that I particularly wanted to drink. It had more of a vegetable taste than a flowery one. I tried experimenting with various ways of improving the flavor: adding lemon juice, lemon zest, limoncello, water, additional vodka, and so on. I tried everything I could think of with no success. I checked on the St. Germaine web site to see if they had any suggestions, but, unsurprisingly their recipe is a closely held secret. I emailed Sean asking him how his liqueur had turned out. He said that it was revolting, so he had thrown it away.

I didn’t tell Sean, but I was embarrassed about the time and effort we had put in for such poor results. I was also anxious about the possibility that my elderflower tree produced flowers that were unsuitable for culinary use. Perhaps, I worried, all of my effort to get this particular elderberry tree had been not just a waste of time, but actively counterproductive.

This year, with the tree grown even larger, the supply of elderflowers was enormous. I was reluctant to drag anyone else into further folly without having a better idea of how to use the bounty of my tree, so, I proceeded on my own. I decided to start by trying to making elderflower syrup for soft drinks.

As before I gathered a bucket of fresh, beautiful, fragrant flowers. I spent considerable time snipping the flowers from their clusters, trying to get as little of the stems as possible – both to avoid the vegetable quality of my failed liqueur and because the greens are slightly toxic. Part way through I discovered that it was actually much easier to pull the flowers off by hand that to cut them off with scissors. Every recipe I have seen refers to cutting, snipping, etc., but for me, bare fingers were really the way to go. If you are working with elderflowers, I recommend giving the hands-on approach a try.

There are many more recipes for elderflower syrup than there are for liqueur. Most of them are quite similar. I chose to base my syrup on one from The Huffington Post.

Here is my (heavily edited) version of their recipe:

Ingredients:

• 1 Kg (2.2lbs) sugar
• 5 Cups water
• 2 Cups elderflower blossoms
• 1 lemon, sliced
• Optional:
• 1 tsp citric acid
• and/or replace part of the sugar with dextrose and/or fructose (corn syrup)

Method:

Mix the sugar and water, adding either citric acid or dextrose and/or fructose. Bring to a boil over medium heat. If using citric acid, boil for 5 minutes after the sugar has dissolved to invert part of the sugar.

Put the flowers and lemon slices in a non-reactive bowl. Pour the hot syrup over them, stirring gently. Cover with foil or a tea towel and let sit in a dark place for 3-4 days, stirring daily.

Strain the syrup and then filter it through a pre-wetted coffee filter. Note that even with filtering a lot of pollen will remain in the syrup. Though it has no impact on the taste, it settles out and looks unattractive. To make a clear product, put the syrup in bottles and decant repeatedly over several days until it is clear enough for presentation.

If it isn’t going to be used immediately, the syrup should be refrigerated, or it can be frozen or stored using standard canning techniques.

[Side note: the author of the blog on Huffington Post provides a recipe that works well, but I believe she is slightly mistaken about the purpose of the citric acid. In her posting she says “It acts as a natural preservative, and helps the syrup stay fresh longer.” However that isn’t really an issue here as the sugar and lemon are preservatives. A whole lemon on average contains about 3 grams of citric acid which is almost as much as the 4.5 grams found in a teaspoon of citric acid powder. Also, if you want to store this syrup you must still take further actions to preserve it, such as refrigeration or canning.

What is really happening with the citric acid in this recipe is that it is being used as a catalyst for inverting the sugar. Sucrose, a polysaccharide, is said to “invert” when it is split into its two components: glucose (dextrose) and fructose. You can invert sugar by boiling it with water. The longer it is boiled, the more of the sucrose will invert. Adding acid causes the inversion reaction to happen more rapidly. A sucrose solution will tend to crystallize over time. The presence of other sugars interferes with crystal formation, so, boiling the solution for 5 minutes with citric acid results in a syrup that is less likely to form sugar crystals (“sugaring off.”) If you don’t have citric acid, or choose not to use it, you can add fructose or dextrose, or boil the sugar solution for more than 5 minutes to achieve the same result. Or you can forget about it and just use the syrup before it crystallizes.]

The elderflower syrup thus created is great with soda water for a cooling summer beverage, and is also excellent over crushed ice.

Having succeeded in making a delicious syrup, I got to thinking about elderflower liqueur again. First I tried simply putting some of my syrup into vodka. The result was 10 times better than last years’ liqueur, but I think it tasted more like elderflower syrup in vodka than real liqueur. [More on this later, but I assume that the difference between an alcohol infusion to which sugar-water is added and a sugar-water infusion to which alcohol is added, is a function of which flavinoids dissolve in water vs. alcohol. If you have further insight into this, please let us know in the comments below.]

Next I put a batch of carefully picked elderflowers in vodka. This time I tasted it after 24 hours. It already had a lot of the flowery flavor I was looking for, but there were also already some vegetable notes. I removed half and let the other half go for another 24 hours. The portion that infused for 48 hours had (to my palate) only slightly more flower flavor, but considerably more vegetable elements. After adding simple syrup I judged the 24 hour infusion to be good, and the 48 hour infusion to be just OK. It was clear to me that 48 hours was a bit much and the 2 to 4 weeks suggested by the honest-food.net author was vastly too long. Though the short-infusion liqueur was good, no one would ever mistake it for St. Germaine, and I doubt anyone would choose my infusion experiments over the bottled product.

I can’t help wondering why I succeeded in making a delicious elderflower syrup, but continued to fail to make elderflower liqueur that is worth drinking. I suspect that the core of the issue is that alcohol is too strong a solvent for my elderflowers, but there are a number of possibilities:

• To infuse elderflowers into alcohol, maybe I need to do something special to avoid extraction of flavors from the stems. Possibly this involves a technique for removing 100% of the green material, or maybe the flowers must be dried or otherwise processed first. Perhaps there is a temperature, pressure, additive, or steam/cooking process that allows the flower flavor to come out without the green taste.
• Alcohol and water are both strong solvents. Perhaps pure alcohol extracts only the desired flower flavors, while using vodka allows the flavonoids in the stems to be released as well.
• In making the non-alcoholic syrup, simple syrup is poured over the flowers while hot from the stove, thus partially cooking them. The vodka infusion is a cold process. The hot syrup might influence the way the flavors are extracted.
• Perhaps the flowers of Sambucus Canadensis ‘Wyldewood 1’ are too delicate for alcohol infusion. Or perhaps the stems of this plant contain more or stronger flavors than other varieties of Sambucus. Maybe my plant’s stems include elements that more readily dissolve in alcohol. Or perhaps this variety of elderberry, grown in my terroir, expresses these undesirable flavors in alcohol.

Next year I may try other experiments with different techniques, or flowers from different trees, to see if I can solve the mystery. But, at least I know my tree can produce delicious syrup, the fruits are excellent, and it is wildly productive.