If you are using sterling silver, the copper alloy in the sterling
is melting at a different temperature, therefore, you will see the
little wrinkling effect. Varying amounts of copper in silver give you
"reticulation" silver, and the result is a great wrinkling effect.
But that is not what you are trying to achieve here.
You won’t see this in fine silver, if using the true granulation
process; same is with gold granulation.
If you place the heat directly at the bottom tip of your wire, any
dirt or grease can cause an uneven melting. I suggest to flux the
sterling wire, heat the wire up and down about the last 5mm from the
bottom and then concentrate the heat at the tip. This will give the
silver time to heat completely and your result should be a nice
rounded ball at the end. Go fast and hot to reduce the wrinkle
With fine silver, you can just heat the tip and you won’t run into
The term “granulation” is NOT creating a rounded ball at the end of
a wire. Granulation is a delicate fusing of a sphere of metal,
usually gold or fine silver and the bonding they create. The top most
skin of the metal is what is melting and the granulation spheres
adhere to this. In gold, the spheres are coated in copper to create a
"eutectic" bonding. This alloy creates a lower melting temperature
for the spheres aiding the granules adhere to the gold, creating a
"fillet" of gold just underneath the sphere.