The second half of the rosetta is the more difficult part to execute. The fishtailing technique is required to form the reversing zigzag of petals that form the slender top of the rosetta design. Most of the challenge with fusing the bottom with the top half of your rosetta occurs in the process of switching seamlessly from shaking to fishtailing. There are many ways to develop this technique.
Usually, trainee baristas pour good bases to their rosettas but find that their latte art design ends up missing many petals. Another tendency is for a barista to end up with a significant imbalance between the number of petals in the base compared with the top. Often, baristas will pour more petals in the base and then rush the fishtailing section of the design.
The most elegant shapes appear to have an equal number of shaken and fishtailed leaves. But the number of leaves is cup-size dependent. For the 240-ml cups we use at Barista Hustle, working to achieve six leaves in the base and six leaves in the top is a great starting point.
Troubleshooting: Missing or Merging Petals
Missing petals: If you have missing petals but you know you are pouring from within the 1-cm range, the issue is likely to be your wavelength. You are probably moving back too far between leaves (i.e., between oscillations). If you use a 240-ml ceramic cup, you will need to move back a distance of approximately 5 millimetres per pair of petals. Remember, you are pouring at a relatively high flow rate of around 20 mL/sec, so this movement will still encourage the northwards movement of each preceding petal you lay down. You don’t need to worry about the lines blurring together.
Merging petals: If your petals do not show good separation between each line, this is probably caused by an insufficient flow rate. If the flow rate drops below 20 mL/sec,