Actually the comment is wrong in that case using BigDecimal.valueOf() is better since it could reuse the immutable object, so that is better for memory.
I'll rework the samples to make it more explicit.
0.5% salt by my calculation is still 2.6 teaspoons (10g) of salt - In 2L of water that does not seem insignificant. When written in terms of percentages it does.
FYI: I'm running a 1920x1200 screen rotated, so with my browser (FF32) as full screen I'm just at the point that the annoying #dd_ajax_float element is shown, but it covers the left edge of the first paragraph.