A tannin stain is a term to describe a group of “wetside” (water-based) stains that have their source in vegetable matter (with the exception of vegetable oils, which are classified as “dryside”). Tannin stains result from the spillage of foodstuffs such as coffee, tea, ketchup, fruit juices, wine, hard liquors, some soft drinks, food coloring, as well as other non-food related staining substances such as grass*, water-based inks, water-based dyes, some types of adhesives, as well as some types of non-topical medicines such as cough syrups.

Tannin stains are usually soluble (in water) when fresh, but quickly become insoluble if they oxidize from age and (or) their exposure to heat. Therefore, an oxidized tannin stain can become more difficult to remove once it has oxidized. Tannin stains are removed with the application of acid-based stain removal chemicals. The removal of a tannin stain will become more difficult if it comes into contact with an alkali. If you cannot identify this type of stain, do not use a protein formula in an attempt to remove it.  Furthermore, since a tannin stain will oxidize from its contact with heat, keep the spotting gun at least 3 inches from the fabric when flushing it. Tannin stains are more difficult to remove if the fabric contains a protein fiber such as silk or wool.

Identification of a Tannin Stain. Tannin stains may be absorbed into the fabric if it is a liquid (such as coffee, tea, or wine). They may appear to be tan to dark brown, depending on the age of the stain or whether it has oxidized. An absorbed tannin stain usually has a smooth outer ring that will darken as the stain ages or oxidizes. Some tannin stains may be built-up (have a surface) on the fabric. Some types of tannin stains that contain pulp or purees such as ketchup, some sauces, and tomato paste will build up on the fabric. These types of tannin stains will develop a hard or crusty surface as they dry, that may or may not be surrounded by a faint absorbed ring.

Work Method

1.      Flush with steam

2.      Apply a tannin formula (neutral lubricant + 28% acetic acid can be substituted)

3.      Mechanical Action- Tamp with a spotting brush a work it with a spatula (“spotting bone”)

4.      Repeat if necessary

5.      Flush and Feather if the stain is removed

If the stain remains:

1.      Apply Oxalic Acid or a Rust remover that contains oxalic acid (do not use a rust remover that contains hydrofluoric acid since they are extremely corrosive and may damage many fabrics and dyes. Consult the manufacturer’s safety data sheet for chemical content). Test with heat from the spotting gun on an unexposed area of the garment before working on the stained area)

2.      Apply heat with the spotting gun-no mechanical action

3.      Apply General Formula (test with heat from the spotting gun on an unexposed area of the garment before working on the stained area)

4.      Mechanical Action

5.      Flush

If the stain remains:

1.      Apply 3% hydrogen peroxide (test with heat from the spotting gun on an unexposed area   of the garment before working on the stained area)

2.      Apply heat from the spotting gun- No Mechanical Action 

If the stain remains:

1. Apply 3% hydrogen peroxide + 26% ammonia (test with heat from the spotting gun on an unexposed area of the garment before working on the stained area)
2. Apply heat from the spotting gun- No Mechanical Action
3. Neutralize with 28% acetic acid, oxalic acid, or a tannin formula
4. Flush and feather

*Green Vegetation such as grass contains chlorophyll. This type of tannin stain can be more easily removed by this procedure:

     1.   O.T.P.R (Oily Type Paint Remover) or P.O.G. (Paint Oil and Grease Remover) + amyl acetate (do not use amyl acetate on polyurethane or spandex)         

     2.   Mechanical Action

     3.   Flush and feather with Volatile Dry Solvent (V.D.S.)

     4.   Tannin Procedure