Field guide

Why so bitter

Fooey! does not claim to be somewhat bitter, quite bitter or remarkably bitter. It holds a registered trademark on the phrase the most bitter stuff on earth, and the recipe behind the brag is refreshingly short.

The first ingredient is grapefruit skin extract. The white pith of citrus peel carries naringin, one of the most bitter compounds found in ordinary food — the reason no animal on earth licks a grapefruit twice.

The second is Andrographis paniculata, a herb so notoriously acrid that centuries of herbalists crowned it The King of Bitters. Where naringin insults the tongue, andrographolides linger — the taste keeps reporting for duty long after the first contact.

Just as important is what the bottle leaves out: no alcohol to sting broken skin or dry a hot spot, no fragrance, no dye to stain the sofa, nothing caustic or flammable. The mix runs pH neutral, which is why the label can say, without flinching, that you may spray it directly on your pet.

That restraint is the practical difference from the classic bitter apple formulas, which lean on isopropanol as a carrier. On furniture the difference is academic; on a bandage edge, a raw lick spot or a bird's cage bars, it is the whole reason to switch.

Purified water, natural bitter principles and preservatives — the entire ingredient deck fits in one line of the label, and every species from ferret to horse reads it the same way: absolutely not.