Tag Archive for cake


Chocolate! Oh my god, chocolate. Chocolate! Master/mistress of our hearts! Emperor/empress of all sweet things! Ruler of our minds! Don’t you know, it has chemicals that make us happy! It has compounds that are the ones that also flood your brain when you’re in love! Or during moments of passion! Chocolate contains chemicals of passion! And love! And happiness! And joy! And all of that! Right? Right?

(Can you just imagine my withering gaze right now? You should get a chill up your spine.)

It’s not right, actually. Of course it isn’t. Of course. It’s never that simple. But saying that chocolate contains happy/lovey-dovey/alluring chemicals is a nifty thing to say, even if it’s not necessarily true, or not true to the extent we think it is. It plays into our beliefs, seems to confirm our existing expectations, and makes us all feel warm and fuzzy and comforted – chocolate will always be there for us, to hold us and nurture us and to spur us to neglect urgent work in favour of going on an epic mission to find chocolate, to console ourselves in its melty embrace, to search desperately through the pantry until we are totally convinced there’s not any chocolate in there, and then to search again just to make sure, and then to walk or drive or ride in a horse-drawn carriage to an appropriate vendor of chocolate-related delights.

But what say you, Science? (Science should be the true master/mistress of everyone’s hearts, OK?)

Science says things just aren’t that clear. Unsurprisingly. Oh, Science. Oh, oh, Science.

Firstly, the most widespread inaccuracy: that a chemical in chocolate – phenylethylamine – is the chemical that also responsible for the feeling of love in the brain, or the feeling of passion, or whatever the latest churnalism article in the Daily Mail (yeah, I’m not even in the UK and I’m going to point my finger at it) or whatever hobbling excuse for a newspaper has regurgitated.

While it is true that chocolate contains phenylethylamine, and that phenylethylamine may have effects on cognition, mood and emotion, very little of the chemical could ever get to the brain, since when it is consumed, most of it is converted into a different chemical by the protein monoamine oxidase-B (Suzuki et al. 1981). Barely any phenylethylamine makes it into circulation in the blood and from there into the brain.

Oh and high levels of phenylethylamine are associated with psychosis, particularly in certain individuals with paranoid schizophrenia (Janssen et al. 1999). Just out of interest.

So everyone can quit jabbering about phenylethylamine. It is really not the magical aphrodisiac love-drug that people make it out to be.

Right, moving on. Theobromine! That’s the next chemical to which people ascribe chocolate’s beautiful, bewitching powers.

There’s actually a little bit more validity in that one, although it’s still not totally resolved and is open to debate.

In one study (Smit et al. 2004), participants were given either:
a) pills containing an amount of cocoa power that would have the same theobromine and caffeine amounts as a 50g bar of chocolate
b) pills containing the same amount of theobromine and caffeine as a 50g bar of chocolate (plus some inactive cellulose as filler)
c) pills containing just inactive cellulose as filler (the placebo condition, naturellement)

Participants in conditions (a) and (b) had faster simple reaction times and reported feeling more energetic than those in the (c) condition. That certainly suggests that theobromine and/or caffeine could be having psycho-active effects: they’re doing something to the brain. But it remains unclear whether it’s just theobromine that’s responsible for the effect, just caffeine, or a combination of both.

To make the conditions of the study a little more relevant to the real-world, doses of theobromine/caffeine were also administered in a second experiment using actual pieces of chocolate. The chocolate was made so that it either had no theobromine/caffeine in it (like white chocolate), a small amount of theobromine/caffeine (the same as milk chocolate), or a larger amount of theobromine/caffeine (the same as dark chocolate). When participants ate the chocolate with the large amount of theobromine/caffeine, it greatly improved reaction time. Chocolate with the small and large amounts of theobromine/caffeine improved working memory (tested by getting participants to press a button when they saw 3 odd or even numbers flash up in a row in a constant stream of numbers on a computer screen). The large and small doses of theobromine/caffeine did not result in participants feeling more energetic compared to the chocolate with no theobromine/caffeine or compared to placebo.

Both of the experiments also found, or rather, didn’t find, something rather interesting: there was no strong, clear effect of theobromine/caffeine on “hedonic tone”, a measure of the participants’ levels of contentment and pleasure. So it seems a bit tenuous that theobromine is this magical chemical that so many people assume must be in chocolate in order for chocolate to exert its effects upon us. But people want there to be a chemical in chocolate that explains why so many people love it – I think people get a kick out of imagining that they’re messing with their brain chemistry in order to elevate their mood or to experience enjoyment, thereby associating chocolate consumption (rather loosely) with illicit drug-taking and getting a kick out of the fact that they’re doing something vaguely taboo like that, albeit on a very diluted scale.

Maybe we should, then, look at what other possible ways chocolate could have established its lauded position as reliable and beloved comforter to many. Is it the chemicals? Or is it something else? Or is it the chemicals and something else?

But maybe I’ll get into that next time.

(See, if I leave you with this tremendously epic cliff-hanger, I’ll feel bad for not following it up again soon, so that will give me the impetus to blog again. It’s like training a puppy! But not really like that at all.)

The photos in this post are of the birthday cake I made for Dr Tash PhD last year, and I tried to make said cake as sour as possible (per her predilection for sourness). I can’t actually remember how I made this cake – I think it was a lemon drizzle cake sandwiched in between two layers of white chocolate mud cake, but I could be wrong. I also have no idea what the purple stars are, except that they were some sort of sour agar gel I made and are not, contrary to appearances, slices of beetroot. Just so you know.

Suzuki et al. 1981. Oxidation of beta-phenylethylamine by both types of monoamine oxidase: examination of enzymes in brain and liver mitochondria of eight species. Journal of Neurochemistry, 36(3), 1298-1301.
Janssen et al. 1999. Does phenylethylamine act as an endogenous amphetamine in some patients? International Journal of Neuropsychopharmacology, 2(3), 229-240.
Smit et al. 2004. Methylxanthines are the psycho-pharmacologically active constituents of chocolate. Psychopharmacology, 176(3-4), 412-419.

Up with this sort of thing

Here’s a pint of Guinness. Now, slán go fóill, y’all, because I’m off to Ireland!

Well, not immediately. (And why yes, I did bake a cylindrical Guinness chocolate cake and carve it into the shape of a pint glass and top it with Guinness foam. Because Guinness cake has been done a million times before so it was time to take it up another notch. BAM!)

But I leave in a bit under two weeks to go and work with collaborators in Dublin for a couple of weeks to analyse the data I’ve been collecting over the past 16 months. Could I have even hoped for better-located collaborators? I think not. After that, my boyfriend Chris and I will be hanging around in Ireland for a few extra days before hopping over to London and taking in as much of the UK as we can over the course of several weeks.

So, any suggestions for particular places we should go? Seriously, anywhere in Ireland or the UK is up for consideration, especially if there is food involved. Leave a comment or e-mail me with suggestions, as they will be greatly appreciated.

Also, since we’ll probably be, you know, hopefully, sort of, kind of busy, it means that once I leave I probably won’t be updating the blog very much until I’m back next year. I’ll do what I can, but alas – I can’t make any promises. I won’t be blogging about my travels since I think of this as more of a food/science blog than a personal blog (if I do come across anything particularly amazing in terms of food and/or science, I’ll certainly try to post it).

However, if you want to follow along with my travels, leave a comment or send me an e-mail to let me know and then when I start uploading photos to the online photo album I use, I’ll send you the link. Last time I was overseas, in April this year, I was pretty good at uploading photos every day.

Sweet sounds

These yuzu chocolate mud cakes with fizzy yuzu icing may be my favourite thing I’ve baked in a long time. The texture of the cakes is ridiculous (it’s kind of like peanut butter, in that it sticks to the roof of your mouth in a delightfully and irritatingly luxurious way). And yuzu, well, I currently pay $40 for a 300ml bottle of yuzu juice (weep!) but I’ve just tracked down Australia’s only yuzu grower, who just happens to be about a 2-hour drive south from here, so if I had a car I would probably be there right now (and possibly passed out amongst the rinds of the dozens of yuzu fruit I had gorged on) but I’ll have to wait a little longer until I can beg/borrow/win a car. Then… everything I cook will have yuzu in it.


Alright, so. Enough yuzu, more science.

Eating food is a multisensory experience. (Hurr durr derp derp that’s pretty obvious.) It’s all pretty damn important when it comes to the perception of food and the enjoyment of eating: the look, the smell, the taste, the texture. But who’s the lonely sense who’s been left out of the party? It’s hearing! Poor, neglected hearing. He wants to come to the party too. He wants to consort with the other senses with reckless abandon. Why won’t you let him? Why won’t you letttt himmmm?

We might not think much about hearing’s contribution to food (beyond the pleasing crunch of crunchy things — more on that in a future post) but it turns out that the brain doesn’t exclude hearing from the party completely. In fact, our brains make implicit associations between tastes and sounds. We might not be aware of them on a conscious level (is a sweet taste high-pitched or low-pitched?) but with the right sort of task, as provided by experimental psychology, we can get a look at the furtive, illicit dalliance between hearing and taste. How thrilling.

So the task is like this. You sit at a computer with your hands on the keyboard. Words are going to flash up one after another on the screen, and they’ll either be sweet words (words like sugar, honey, maple syrup) or salty words (words like salt, crisps, pretzel). Sometimes you’ll also hear sounds played over some headphones (2 seconds of sound played on an instrument such as a violin, piano or bassoon). The sounds will either be high-pitched or low-pitched. You and some other participants start off the experiment on Condition 1, then change to Condition 2 (while other participants will start on 2 and change to 1).

Condition 1
Press the A key if: you see a sweet word or hear a high-pitched tone.
Press the L key if: you see a salty word or hear a low-pitched tone.

Condition 2
Press the A key if: you see a sweet word or hear a low-pitched tone.
Press the L key if: you see a salty word or hear a high-pitched tone.

You as a participant probably won’t notice anything amazing during the experiment. But when the researchers look at your reaction times (i.e. how fast you were at pressing the correct key after you saw a word or heard a sound) they’ll notice something very interesting. You responded significantly faster in Condition 1 than in Condition 2.

For some reason, you’re faster when a sweet word and a high-pitched tone are associated (Condition 1) than when a sweet word and a low-pitched tone are associated (Condition 2). Likewise, you’re faster when a salty word and a low-pitched tone are associated (Condition 1) than when a salty word and a high-pitched tone are associated (Condition 2). Somehow, the sweet-high and salty-low combinations just make more sense to your brain, enabling you to react and identify them more quickly — and more accurately, since participants made fewer errors in Condition 1 (although the error rates in Condition 1 and 2 weren’t significantly different statistically).

Another study using the same kind of experiment found a significant association between sour words and high-pitched sounds, and between bitter words and low-pitched sounds. However, these researchers have also tested sweet, sour, salty and bitter altogether using a different task, and the pitch associations for salty and bitter disappeared, although the associations between sour words and high-pitched sounds and between sweet words and high-pitched sounds were still there. Hmm.

And it seems like we don’t really have a good explanation for why the brain does this. There are plenty of ways of drawing parallels between properties in different senses — for example, when comparing hearing to vision, the loudness of a sound might be thought of as the equivalent of the brightness of a colour, since increased loudness and increased brightness are both experienced by us as being more “intense”. So maybe we just don’t have a good enough grasp of the properties of taste to be able to figure out something like why sweet is somehow a parallel for high-pitched. Is there a biological basis to the association? Or is it cultural somehow? Do people from different cultures experience the same associations? Would the results be any different if actual tastes were used (e.g. a bit of sugar on the tongue) instead of taste-related words?

And… and… can we influence the perception of taste by using sound? If the basis of the association is biological, maybe closely connected or overlapping brain regions are responsible for sweet tastes and high pitches. There certainly is overlap between the hearing and taste sensory pathways, not just at later stages of cortical processing but in the early stages too, as the primary taste cortex (which I discussed in my previous post) is located partly in the insula, which also plays a pretty big role in auditory processing (Bamiou et al. 2003).

So it’s a big and tenuous jump, but… can we influence the perception of taste by using sound? If the association is due to neuronal connectivity, would something taste sweeter if we played high-pitched music compared to low-pitched music? Or would something just taste wrong somehow if sound that wasn’t associated with it was played? Intriguing possibilities…

Recipe for yuzu chocolate mud cakes with fizzy yuzu icing under the cut. Recommended serving suggestion: high-pitched sounds, naturellement.

Black tea red velvet cake and fear of the unknown

I made this cake for Father’s Day (which was only a week ago for Australia, New Zealand, Papua New Guinea and Fiji, in case you thought I was posting a recipe I made in June… or any other of the assorted dates Father’s Day falls on around the world) and, being the calculating and malevolent character that I am, I forced everyone to guess what this particular red velvet flavour was and refused to tell anyone until they guessed its exact identity. NO CLUES! And if they didn’t guess it, well, they would just have to live with never, ever knowing, and it would be all their own fault.

Apparently that was the wrong thing to do, according to research. According Okamoto et al., when a person knows what they’re tasting, they rate the flavour as significantly more likeable compared to when they’re just given something mysterious and have to taste it without having any idea what it is. Participants in the study were given a range of flavoured liquids to taste. In one condition, the samples were labelled with their correct flavour names (“lemon”, “caramel candy”, “consommé soup” and “coffee jelly”… this interesting selection of flavours may have something to do with the study being conducted in Japan). In another condition, the samples were just labelled with a random number. Participants rated their liking for any given liquid’s flavour on a scale of -100 to +100, and it turns out that they liked a liquid when they knew what it was much more than when they didn’t know what it was, even if it was the exact same liquid.

Moreoever, the average rating for name-labelled liquids was above zero, which meant people liked them, whereas the average rating for number-labelled liquids was below zero, which meant people disliked them — the exact same liquids. You can make someone dislike something that they might otherwise like, just by not telling them what it is! Not telling people what a flavour is is a bad idea! So I issue this public apology to my family, whose experience of red velvet cake may have actually been marred, nay, ruined by my megalomaniacal obsession with forcing everyone to eat the cake and guess what flavour it was.

Then again, I’m not sure if a label with a random number on it was a good control condition for that study. I would say that in the context of food and drink, numbers are usually associated with artificial flavourings and preservatives, and a lot of people like to avoid those wherever possible. Getting a mysterious liquid with a mysterious number on it: yeah, I might not like it so much either. If I liked it, I’d mysteriously number my own drinks to get that thrill of the unknown.

So consider not serving people something like, say, duck surprise, without at least telling them what the surprise is. Otherwise, no matter how good the surprise is (“It’s stuffed with red velvet cake!”), they might not like it.

Okamoto et al., 2009. Influences of food-name labels on perceived tastes. Chemical Senses, 34, 187-194.

Recipe for black tea red velvet cake (full name: Earl Grey black tea red velvet cake, just to get another colour in there) under the cut.

Red velvet cake with raspberry cream cheese icing

Red velvet recipe #8402445, red velvet cake with raspberry cream cheese icing. Made as a large double-layered cake for my mum for her birthday (happy birthday!) but some leftover batter got made into cupcakes as seen in the photo.

I’ve been wanting to make a raspberry red velvet cake for ages, just because apparently that’s one of the more common red velvet permutations in the wider world. Well, I guess in the U.S. maybe, since red velvet is pretty uncommon in general here in Australia… although they’re never going to convince anyone of red velvet’s worth if they don’t try to sell it convincingly.

For example, at the lovely Poppy Cakes a while back, I overheard a rather loud woman shout at the baker “WHAT FLAVOUR IS RED VELVET?” while gesticulating at some red velvet cupcakes, and he replied with “Well… umm… it’s kind of a mix of vanilla and cocoa…” and of course, Rather Loud Woman immediately ordered a chocolate cupcake with chocolate icing.

The baker didn’t sell the mystique, the ineffable, transcendental flavour of red velvet that dares the English language (and probably all other languages ever) to even attempt to describe it. The look on people’s faces when they try red velvet for the first time is remarkable because it’s the look of realisation that language, in this moment, is useless to them.

So if the question is:
What flavour is red velvet?

Then the answer is:
You wish you knew what flavour red velvet is! It’s the flavour that will have you yelling “Where have you been all my life?” in a wounded, accusatory tone after you first try it! Your life is all the poorer for not having tried it, the whole is greater than the sum of the parts, oh just try it already and stop wasting away in pathetic ignorance of its greatness of which you are quite possibly not worthy. Now is your chance to enlighten yourself.

Then either the person will try red velvet, or they will flee. What am I, a customer service representative?

You know the rigmarole with the standard red velvet recipe. And the icing?

Raspberry cream cheese icing
500g cream cheese, at room temperature
100g unsalted butter, softened
1/2 cup icing sugar, sifted
1 tsp vanilla paste
400g frozen raspberries

Put the frozen raspberries in a saucepan and cook them over medium-low heat until they reduce down to a thick liquid. Remove from the heat and leave to cool slightly. (This works best with frozen raspberries, which I only used because I didn’t feel that the fresh raspberries were worth $9 a punnet, but you could use fresh raspberries in a similar way.)

Beat the cream cheese and butter together in the bowl of an electric mixer with a paddle attachment until well combined. Add the vanilla and beat again, then the icing sugar and beat again. Add the slightly cooled raspberries and beat until well combined, then ice your red velvet cake/s.