NATIVE penicillin was dark and swarthy , greasy-looking, smelt of garlic , carried a stiletto and was unreliable and unpredictable

Well it often was a dark dirty reddish brown and so often did look like dry mustard that had absorbed water from the atmosphere and had darkened and moistened at the bottom of the jar.

And indeed it did reek - but less of garlic and more of a musty basement or newly turned humus-rich soil.

By contrast, white (man-made) penicillin (as yet unseen and in fact never yet seen) was widely/wildly predicted by mainstream scientists to be as pure as a Boy Scout and as predictable, reliable, dependable as clockwork.

Who ever said that scientists don't have a rich fantasy life ... or a privileged access to bad acid ?