While an attempting on a creation of a latte art, there are few major parameters that anyone has to concentrate on. Because, those wonderful creations will not rise just upon luck.
Any barista, who creates latte arts, has to understand the behaviour of the milk, against temperature and conscious or unconscious perception of milk and its chemistry. At texturing the milk there are few things that help to understand the structural or otherwise physical attribute of milk by looking at the predominant chemical compounds within. Such as proteins (whole -3.4/100ml, skimmed- 3.6/100ml) help the suspension of the air molecules in the milk while fat (whole -4.0/100ml, skimmed-0.3/100ml) helps to stable the micro foam. Above understanding will creates the ability to introduce the right techniques at milk texturing or foaming.
Proteins help to suspension of air particles within milk therefore; skimmed milk is easier to foam. At the same time hydrophobic and hydrophilic parts of fatty molecules, will help to create inter molecular bonds and surface tension with air particles. Thus higher fat levels will decrease the production of foam. Therefore; baristas have the ability to control the formation of foaming milk rather easily when whole milk is being used.
Profound understanding about fat and protein levels of milk, allow baristas to plot the changes of structural and chemical behaviour while milk is being heated. Above understanding will create the ability to pour milk while it has been heated up to its sweet spot rather than pouring a latte art with milk which has rotten egg yolk flavours.
Let’s talk about the sweet spot of the milk. While milk is being heated, most of the lactose (C12H22O11 – molecular mass 342.29 g/mol) will separated into sub group of sugar;Such as galactose(C6H12O6-180.15g/mol) and glucose(C6H12O6 -180.16 g/mol). Therefore hot milk is sweeter than cold milk. Optimum temperature of this happening is around 60’C (140’F), is known as the sweet spot of the milk.
Even though there is no any right way or wrong way to tilt the milk pitcher at texturing or cup at pouring, significance of the tilting angle of above situations to Y-axis, will become a major parameter depending on the choice of the latte art.
Roasting profile of the bean, the amount of the lipid concentration (Arabica- 17%of dry weight , Robusta-11% of dry weight),average density(Arabica-1.01g/ml,Robusta-1.02g/ml), viscosity(Arabica-1.65-1.70mPa.s , Robusta-1.75mPa.s), surface tension (Arabica-46 mN/m , Robusta-49 mN/m)of the extracted yield will force baristas to adjust their pouring at creation of latte art as above parameters can bring a latte art to an unsymmetrical finish across the cup. As mentioned above, perceptions of this little details and numbers consciously or unconsciously (by practical experience), can extend the probability of producing a fine latte art.
Tilting angle, wrist positions, pressure on pitcher of pouring hand, right understanding on extracted yield, velocity of the milk while it is contacting the yield, equilibrium of contrast of milk within the yield, simple harmonic motion of pouring and symmetrical finish; are few of the controversial calculations or rather theses that understand by a baristas within their own mind, in order to complete a fine latte art.
Therefore, Exquisite latte art can be created, when simple harmonic motion of the jug is unforced at pouring, as I believe latte art always be a catalyzer where balanced espresso has been percolated.
Along the scale of the time, profound understanding of coffee science and latte art can bring the manufacture of coffee to a beautiful level. Because, when science meets arts, miracles are born.