What Is Leather Spew?

It’s a substance that rises to the surfaces of the leather hides, this is oils and fatliquors that have risen to the surface leaving behind a crystal-like effect, almost like a white or brown powder effect. It’s known as Leather Spue or Spew and can also be called Fatty Bloom.

People often mistake Leather Spue for mould as its characteristics are very similar to a damp mould growth like a white thin film.

Leather Spew On The Surface

Fatty Bloom or Spew Migrated To The Surface Of The Leather


Due to people mistaking Spew or fatty bloom as mould, you can tell if it’s mould or Spew by carrying out a very simple test using a hairdryer. Spew will melt when heated up, so always heat up what appears to be Leather Spew or mould with a hairdryer If it’s Spew it will melt as it’s fat that has migrated to the surface.

A normal cleaner will remove the Leather Spue but this will return again, you need to use specific cleaners to remove Spew.

Once you have cleaned the area with the Spue Remover, allow the item to sit for a few hours before cleaning as normal. Delicate leathers like Veg Tanned, Bridle Leather and Aniline Leather have to have great care taken when cleaning.


Spue or Spew its known by both names, there is no standard what name is used, as some use both or either one of them.

in Leather Tags: leather spewmigrationspue