The congener of “TCP” is parts of the “medicinal” sub category as part of the “peaty” head category.

For an overview one can look at this page on the “the good scents company” website. This website does not have a “peaty” congener, but it does have one for “medicinal”. This page lists many chemical compounds that are considered to describe the congener of “Medicinal”.

TCP” is a congener that is chemically linked to not to many chemicals. In fact this one is linked to a very specific one : Trichlorophenylmethyliodosalicyl


Or at least it was until the 1950’s. Then it got changed to an aqueous solution of Phenol 0.175% w/v and halogenated phenols 0.68% w/v. Other ingredients: glycerol, concentrated phosphoric acid, quinoline yellow (E104) and purified water.

Other sources give a composition of TCP as a liquid antiseptic 40% w/w (chlorine 0.4% w/w; iodine B.P. 0.055% w/w; phenol B.P. 0.063%; sodium salicylate B.P. 0.052% w/w with partial elimination of ionisable chlorine); 2,4,4′-trichloro-2′- hydroxydiphenyl ether 0.1% w/w; water miscible creambase 59.9% w/w. But this could be explained the Chlorine combining with the iodine and phenol to end up as the composition of mentioned in the previous paragraph.

TCP is also known in the computer industry as TCP / IP or Transmission Control Protocol / Internet Protocol. This is a computer communications protocol and it really doesn’t do anything for your whisky, accept maybe help bring this blog onto your screen.


According to the book ‘Whisky Technology, Production and Marketing”, Elsevier, 2003 the medicinal congener is credited to o-cresol. This is based on a figure shown which is taken from this article : “Analytical Strategies to Confirm Scotch Whisky Authenticity”
Ross I. Aylott, Angus H. Clyne, Anthony P. Fox and David A. Walker, Analyst, August 1994, Vol. 119.


The article itself does not link the word medicinal to o-cresol. Please note that spike 4 is o-Cresol and spike 1 is Phenol. Phenol is one of the compounds of TCP.

One makes the observation that o-cresol does not seem to be a chemical component of TCP. Here too, just like with “kippers” and “smoked cheese” the people that made the flavour wheel choose to describe a household scent.

Quote from “Origins of Flavour in Whiskies and a Revised Flavour Wheel”: a Review By K.-Y. Monica Lee, Alistair Paterson* and John R. Piggott. Volume 107, No. 5, 2001

On drinking a glass of whisky, consumers employ pattern recognition processes, using sensory data to develop a holistic mental image in specific regions of the brain. Flavour recognition involves matching of information from long-term, short-term and sensory memories. Whisky maturation influences volatile congener release into head spaces through modifications of spirit liquid phases, and agglomerates. Complex changes in congener partitioning replace immature notes in new distillates with matured whisky characters.

The revised flavour wheel specifies a vocabulary that defines consensus deconstructed attributes of whiskies to meet industrial needs. Each attribute is demonstrable by a flavour standard and terms suitable for training of sensory assessors for quality assurance, new product development and similar purposes.

Is phenol or o-cresol a component of whisky. Yes it is. The article written by Ross I. Aylott, Angus H. Clyne, Anthony P. Fox and David A. Walker clearly shows this.

I am left with the un-satisfaction of not making a direct link between a chemical component in TCP that is directly linked to 0-cresol. Phenol yes, but not o-cresol.

Aww well, I will probably life!