Next week we are getting together TWICE with Rachel Khoo; foodie and chef extraordinaire, to discuss (and savour) craft chocolate.
We’ll be trying six different chocolates together with you and using these to illustrate everything from her Parisian adventures to her latest TV programme (see here and below for more details). Whilst savouring these bars with Rachel, we will explore how you can savour craft chocolate in some slightly odd ways, including spitting out some craft chocolate after you’ve allowed it to melt and chewed it a bit.
Even if you can’t join either of these events with Rachel, we’d still invite you to chew, and then spit out a small part of your next craft chocolate bar. Please read on below for the logic and science behind this.
Snap, Sniff, Swirl, Savour
As we’ve learnt through our virtual tastings with wine and coffee experts, the first step to savour a wine or coffee is to ‘sniff’ and then to ‘slurp’. A HUGE variety of aromas and flavours immediately emerge as you sniff (otherwise known as orthonasal olfaction). Then, when you slurp, a whole load of new flavours, tastes and sensations are revealed. And yes it is definitely worth slurping air over the coffee and wine (for a FANTASTIC example of how to do this, please see the Japanese movie Tampopo which demonstrates this for both wine and ramen, see the picture above and video below).
Whilst in your mouth, the flavours here are detected by what is called retronasal olfaction (i.e. the flavours and aromas are detected by your olfactory bulb via the back of your mouth). At the same time, tastes are detected by receptors all over your tongue and mouth (and down to your gut, and possibly even further). Plus various sensations are felt by other nerves via chemical reactions in your mouth (for example, we immediately detect texture or bubbles, and then tannins in wine, coffee and chocolate dry out your mouth (astringency) via chemesthesis).
Chocolate savouring is a bit different. We recommend first looking at the chocolate, then ‘snapping’ it, then you can try to sniff. But, unless the chocolate has melted a bit, it’s hard to get much smell (orthonasal olfaction). If you heat the chocolate by scratching a bit off and rubbing it between your fingers, some flavour aromas and smells (volatiles) can be released. The real delight with chocolate happens once you put it in your mouth and the chocolate starts to melt. Wait for a few moments, and then the world starts to pop as flavours emerge from the melting, masticated chocolate. Note: this assumes that the chocolate has a good snap – ie it’s properly ‘tempered’ so it will melt. If you’ve stored your chocolate in the fridge, or left it out in the sun etc., it may well have ‘badly tempered’ to crystal structure 6 which won’t melt in your mouth (but it’s fine for cooking with…). Read about this elsewhere on our blog.
What causes these different flavours?
If you’ve ever had the (mis)fortune to try a cacao seed straight from a cocoa pod you’ll know the sensation is a million miles away from chocolate. A fresh cacao seed is incredibly bitter tasting and astringent. It has none of the flavours, or mouthfeel, of chocolate. It’s not pleasant. Indeed, it’s amazing to think that chocolate bars come from these bitter, astringent seeds.
But through the magic of fermentation, drying, roasting, grinding, conching and then tempering, these seeds are transformed into chocolate. Each of these steps breaks down and transforms the cocoa into its constituent amino acids, sugars and pyrazines. And the end result is CHOCOLATE, with myriads of flavours, tastes, textures and pleasures.
Please see Harold McGee’s “Nose Dive” for a fantastic description of the complexities.
And here is a detailed overview of how each step from bean to bar impacts flavour:
Cocoa Bean Varieties
- Different cocoa varietals have different pyrazines, amino acids (including in particular methylbutanal, with its chocolatey smell) and sugars. Just as different grape varieties can yield distinctive flavours and tastes, the same is true for different cocoa varietals.
- Once the cocoa pod is opened, the pulp starts to ferment as it reacts with different yeasts and bacteria, creating ascetic acids (technically microbial enzymes break down the sugar in the cocoa pulp into alcohol and thence acetic acid). These acids in turn break down the seeds into different amino acids, sugars and pyrazines. And then it becomes even more complex; the various pyrazines in different cocoa varieties react in various ways to the myriad of yeasts and bacteria in each growing ‘terroir’, creating even more flavour potential.
- Most beans are ‘sun dried’, but in very rainy cocoa growing areas (Papua New Guinea and Indonesia for example) fires are needed to dry the beans and the smoke from these can permeate the beans. Drying needs to be done really carefully; failing to dry fermented beans will cause them to go mouldy and over-drying them destroys many aromas and flavour volatiles.
- Roasting the beans creates a series of Maillard reactions that further develop the pyrazines in the cocoa (roasting also changes the colour of the chocolate). Mass produced chocolate generally roasts the nibs (i.e. the beans separated from its shell) as this is more efficient, however it drastically diminishes flavour development potential.
Grinding and Conching
- Grinding turns the beans into a paste where other ingredients (for example sugar and other flavourings) can be added. In addition, the heat generated can create a Maillard reaction. Most ground chocolate is then ‘conched’, where a surface scraping mixer and agitator (called a conche) distributes the cocoa butter within the chocolate whilst also ‘polishing’ the chocolate so it moves from being grainy (as in stone ground chocolate) to being smooth and polished. Conching also promotes more flavour development, releasing more flavour volatiles, acids and oxidation. To make some sweeping generalisations about conching:
- Air flowing through the conche removes some unwanted acetic, propionica and butyric acids from the chocolate and reduces moisture.
- Cocoa butter is generally used to clean the machines (instead of water) to increase the mouthfeel and viscosity of the chocolate.
- Oxidation also occurs, with the heat in the conche often ‘mellowing’ various flavours.
- Tempering is a term used in chocolate (and metallurgy) that describes the process of heating and cooling chocolate like steel, to achieve a desirable crystal structure. For chocolate, this is to melt in your mouth (and the chocolate needs to be at crystal structure 5). For steel it’s about creating properties such as consistency, durability or hardness. Chocolate’s physical structure is largely down to cocoa butter (which itself comprises mainly of oleic, palmitic and stearic fatty acids). Cocoa butter is a six-phase polymorphic crystal, and it’s the application of heat (tempering) which enables the cocoa butter to form crystal structure 5, which literally melts in your mouth, and releases all the flavour volatiles and aromas.
Note: this list is an overview only; it leaves out the impact of adding milk, ageing bars, and much more.
And what’s all this got to do with salivation?
When you put chocolate in your mouth, its flavours are revealed in two very different ways:
- Firstly the heat from your mouth and tongue releases many of the flavours and volatiles in the chocolate.
- Secondly the enzymes in your saliva react with the chocolate to release even more of what are called ‘bonded flavours’.
Chocolate: The Unique Solid which Melts in Your Mouth
To illustrate the way heat reveals chocolate’s flavours just try holding your nose and popping a morsel of chocolate in your mouth. Wait for 10 seconds and then release your nose, and breath in through your mouth.
As you release your nose, you allow your olfactory system (sense of smell) to start working again, and because the chocolate has now melted, a wave of flavours should bombard you.
As anyone who has been to a virtual craft chocolate tasting will attest, this is quite easy to do (you will NOT suffocate!), and it’s fun to watch people’s jaws drop as the flavours hit them.
Saliva and Spitting
The saliva in your mouth has a set of magic to perform on chocolate (and other foods and wines).
For the last couple of decades, more and more work has been done to understand the process by which when we cook foods we ‘bind in’ flavours and aromas that we can later release through microbes in our saliva. Arguably the first industry to really work this out was the wine industry, where back in the 1980s, the wine chemist Emile Peynaud noted how wines “smell more of the flavour of the fruit than the grapes themselves”. He went on to describe how saliva amplifies and catalyses flavours: “saliva reacts with and releases the (herbaceous .. bruised leaves) in Sauvignon which is present in the grapes in a relatively odorless form”.
And this is what happens when we savour chocolate. As anyone who has ever savoured craft chocolate can attest, the flavours just keep evolving. This is more than simply melting the chocolate to release flavour volatiles, it’s because you need to allow more time for your saliva to break down these ‘bound volatiles’ (created by fermenting, roasting and grinding the cocoa), and ‘liberate’ them for your olfactory bulb.
There is a simple trick to illustrate the power of saliva’s microbes: Chew some chocolate in your mouth for ten to twenty seconds. Then spit it all out. Wait for another ten to twenty seconds and you should be able to detect a whole load of new flavours. Even though you’ve spat out the chocolate, the microbes in your mouth will continue to release aromas and flavour volatiles from the chocolate you’ve spat out. Note: you can do the same by swallowing the chocolate, but it’s not quite so graphic an example of ‘saliva in action’.
The Flavour Wave
As anyone who has been to a virtual tasting will know, the first thing we do at a craft chocolate tasting is have you hold your nose when trying a piece of chocolate. This is a pretty fast way to explain the difference between taste and flavour, and how melting releases some of the flavours in chocolate.
Then we present a “Flavour Wave” which we developed along with Professor Barry Smith (philosopher and more), James Hoffman (coffee expert) and Rebecca Palmer (wine expert). The wave helps in a number of ways, including the impact of saliva.
- It provides a useful crib sheet of descriptions for what you are sensing. This solves the challenge many of us have in not being well-versed in articulating flavours or tastes. Unlike, for example, colours, there aren’t clear definitions and we lack vocabulary and practice, so very often the words are “on the tip of your tongue”, and a gentle nudge can then work.
- It provides an interesting foil to the Laing Limit – the limitation we all have in identifying more than 3-4 flavour notes at any one time.
- Having you repeatedly search for different flavours and tastes as they evolve so you can detect more.
- Seeing what other people are sensing also helps you identify some of these flavours, tastes and sensations as they bring them to your attention.
- It slows you down, and allows your saliva to do its work, liberating all the bound flavour volatiles.
Please see here for a downloadable PDF of the wave.
One final thought. As lockdown continues to ease, and the weather continues to improve, and as we look forward to Mayday bank holiday here in the UK, more and more people are enjoying barbecues, picnics, beer gardens and the like. Please do consider bringing along a couple of craft chocolate bars to these festivities. Bars are very portable and great for sharing! And you can show off your credentials as you snap, savour and (sometimes) spit.
Please see below for a few more pairs of bars that we’ve selected to go with a smokey barbecue (smokey bars from New Zealand), picnics (some all time favourites) and some ones for the beer garden (a couple of fruity numbers).