Sunday, April 17, 2011

Caramel E150

Spirit caramel (E150) is allowed as a colouring agent in Scotch whisky production. There are four different types of E150, labeled from a to d, or from class I to IV, according to the manufacturing process used. E150a (plain caramel) is "prepared by the controlled heat treatment of carbohydrates (commercially available food grade nutritive sweeteners which are the monomers glucose and fructose and/or polymers thereof, e.g., glucose syrups, sucrose, and/or invert syrups, and dextrose). To promote caramelization, acids, alkalis and salts may be employed" (not ammonium compounds or sulphites). Sulphites are allowed in the production of E150b (caustic suphite caramel), ammonium compounds are allowed in the process for E150c (ammonia caramel) and both suphites and ammonium compounds are allowed in the process for E150d (sulphite ammonia caramel). Common raw materials for caramel colourings are corn syrups, wheat, glucose syrup or sucrose. Additives may include a variety of acids, alkalis and salts. Different raw materials produce different caramels and the use of additives influences the resulting color, viscosity, ionic charge and pH and there are hundreds of different spirit caramels available from several producers.
Caramels from DD Williamson. 570 is their most used spirit caramel.

Caramel samples from Sethness. Typical spirit caramel is 0.075-0.110
Most caramel colourings are very dark in color and are usually used in tiny quantities. Fructose produces the darkest color, probably because it starts to caramellisate in 110ºC, as sucrose, glucose and galactose caramellisate in 160ºC and maltose in 180ºC. Viscosity varies, but in general low viscosity caramels are used in beverages. The ionic charge of caramel is important because of possible flocculation. For example, if negatively charged caramel is added to positively charged beverage, there will be some flocculation or even percipitation. Correctly selected caramel colouring has some emulsifying properties, in other words it helps the oils to mix with the water. In fact, the Coca Cola Company first patented the caramel colouring as an emulsifying agent, not as a colourant. Whisky and most soft drinks are negatively charged, but beer, baked goods and herbal liqueurs have usually a positive charge. E150c is positively charged and used in breweries and never in whisky. E150a has the best stability in high proof alcohols, especially when the raw material has been sucrose. Wheat and corn based syrups are widely used, but they are usually less stable in alcohol. E150a can tolerate up to 75% abv as most E150d is guaranteed to work up to 50% or 60% abv. E150b is used in the presence of tannins, especially in sherries, wines and some brandies and the residue sulphites of E150b probably also help to preserve the wine from excess oxidation. The amount of caramel varies, in spirits it is usually about 0,1-0,5% or about 1-5g/litre as in comparison some 0,4% of E150d is used in cola soft drinks, 0,01-0,3% of E150c in beers and up to 10% of E150d in (cheap) cocoa powders. EU (EFSA) recently lowered the acceptable daily intakes (ADI) for caramels; 300mg/kg/day for E150 and 100mg/kg/day for E150c, so a man weighing 80kg is allowed to consume 24g of caramel color a day. Hopefully not many of us get that from blended whisky, but probably some will get those amounts from cola and bakery stuffs.

Most producers give caramel colors a two year shelf stability guarantee, if stored in room temperature and protected from sunlight. Sunlight fades the caramel colors rapidly, in matter of weeks to months. E150a is the most resistant to fading and it fades evenly in all wavelenghts, as E150d usually fades more of the higher wavelenghts (red fades first).
Loch Dhu, mit farbstoff

The majority of single malts and virtually all the blends are coloured with E150a. The Scotch Whisky Association (SWA) published The Scotch Whisky Regulation in 2009, which states that only "plain caramel" (E150a) is allowed. This is just a guideline for the members of SWA and in fact the UK and EU laws permit the use of "spirit caramel", which is not exactly defined in law and can be any E150 and so at least some E150b and E150d have been used in Scotch whiskies.

Toasting a barrel (
Due to the variety of raw materials and additives, the chemical structures of caramels are complex and there are lots of variations even between caramels of the same subgroup. In the production the main reaction is dehydration as water (hydrogen and oxygen) is extracted (boiled) out of the sugars. This results first to sugar monomers as polysaccharides (for example sucrose) are divided into glucose, fructose, galactose, xylose and maltose. As the heating continues, the monosaccharides lose water and react with each other producing big polymers, mainly caramelans (C24H36O18), caramelens (C36H50O25) and caramelins (C125H188O80), which give the caramel most of its color. Additionally some residue sugar may be left in the product and several flavour components are produced, for example different furans, diacetyl, maltol, esters and lactones. Furans are probably the most influential flavour components in most caramels, they are formed especially from fructose or sucrose (containing fructose) in acidic encironment. They also form during the toasting of oak barrels, but the relative amounts of different furans are different as the raw material are either lignin and (hemi)cellulose in oak or simple sugars in caramel. Caramellisation of simple sugars produce less furfural (almond, walnut, grainy) and more 5-hydroxymethylfurfural (butter, musty, waxy, caramel) than caramellisation of oak (there are also significant differences between different oak species, see previous blogs). 5-HMF is not produced if sulphites or ammonium are used in the process (E150b or E150d), but is formed in large quantities in the plain caramel (E150a). 5-HMF is also used as a flavour enhancer in milkpowders, honey, juices and even cigars. Furfural acts as a reactant with various compounds in the spirit; it has some antioxidative properties that slow the oxidation reactions and help to stabilize the color from antocyanins (in especially wine), it also reacts easily with H2S (rotten eggs, nasty sulphur) producing furfurylthiol (strong coffee), decreases the volatile sulphur compund concentrations and potentiates the odor of oaklactone (vanilla,coconut). Some other furans such as hydroxyacetylfuran (sweet), hydroxydimethylfuranone (also known as furaneol, additive in baked bread, coffee and chocolate) and dihydroxydimethylfuranone are also produced. Diacetyl imparts a buttery (butterscotch) flavour and maltol (aka E636) gives freshly baked bread aromas. Esters and lactones (here from sugar, not oak) are usually fruity. Also increased levels of E2-nonenal (cardboard, stale beer) and less hop flavour are also found in caramel coloured beers, but this possibly results from changes in fermentation process and is not studied properly in spirits.

So, caramel does affect the flavour and it is not inert in whisky, but are the quantities used in Scotch whisky industry enough to affect the overall flavour significantly? No reliable scientific fact exists, but my guess is that they probably are significant. Does caramel impair the flavour? It could, but then again in some cases caramel might even improve the taste.

References and further reading:
Abalos D et al. The use of furfural as a metabolic inhibitor for reducing the alcohol content of model wines. Eur Food Res Tech 2011;232;663-669
Blanchard L et al. Formation of furfurylthiol exhibiting a strong coffee aroma during oak barrel fermentation from furfural released by toasted staves. J Agric Food Chem 2001;49;4833-4835
Boscolo M et al. Spectrophotometric determination of caramel content in spirits aged in oak casks. J AOAC Int 2002;85;3;744-750
European Union Directive 95/45
Furukawa Suarez A et al. Impact of colour adjustment on flavour stability of pale lager beers with a range of distinct colouring agents. Food Chem 2011;125;850-859
Laws DRJ, Peppard TL. The stability of flavour constituents in alcoholic beverages. Food Chem 1982;9;131-146
Quesada Granados J et al. Influence of aging factors on the furanic aldehyde contents of matured brandies: aging markers. J Agric Food Chem 1996;44;1378-1381
Ratsimba V et al. Qualitative and quantitative evaluation of mono- and disaccharides in D-fructose, D-glucose and sucrose caramels by gas-liquid chromatography-mass spectrometry di-D-fructose dianhydrides as traces of caramel authenticity. J Chrom A 1999;844;283-293
Rodriguez Dodero MC et  al. Phenolic compounds and furanic derivatives in the characterization and quality control of brandy de Jerez. J Agric Food Chem 2010;58;990;997
Scotch Whisky Regulations. Scotch Whisky Association 2009.
Sousa A et al. Isolation and structural characterization of antocyanin-furfuryl pigments. J Agric Food Chem 2010;58;5664-5669
Tsai PJ et al. Interactive role of color and antioxidant capacity in caramels. Food Res Int 2009;42;380-386 (DD Williamson)


  1. Great article, Teemu, even if some of the chemistry was over my head. Very thorough.

  2. I love this blog, Teemu. It hits just the right balance of technical knowledge and casual tone; not dry like reading academic work on the subject but not fluff filled like most Scotch info. Thanks a lot.

  3. Fabulous piece Teemu. I once did some testing with E150a and when used for blending the stuff works like a glue on the taste. It stiches them together, makes them round. I'll will add a link to this from my blog. Thanx!

  4. Tervehdys Teemu, blogissasi on paljon mielenkiintoista tietoa. Sen verran toivoisin, etta merkitsisit selkeasti ne osiot tekstista, jotka ovat suoraa lainausta (ja myos sen, mista artikkelista tarkalleen), kuten on tapana tieteellisessa tekstissa. Muuten lukija jaa miettimaan, kuinka suuri osa on sinun omaa tekstiasti, ja kuinka suuri osa suoraa lainaa muista artikkeleista, jotka listaat blogikirjoitustesi alla. Ilman selvia viitteita voisi luulla, etta esim. yllaoleva teksti on taysin sinun tekemaasi.

    Ystavallisin terveisin,

    Mika R. Jansson

    1. Kiitos palautteesta. Pyrin kirjoittamaan tekstini kokonaan itse, yksittäisiä lauseita voi joskus pujahtaa sekaan suoraan lähteestä samanlaisena, plagiointia pyrin kuitenkin välttämään. Lähdeluettelot ovat puutteellisia ja viitteitä en ole tarkoituksella käyttänyt. En pyrikään tieteellisen artikkelin laatuun, sillä sitäkin hommaa tehneenä tiedän, että se veisi turhan paljon aikaa ja vaivaa.

    2. Hyvää tekstiä ja sopivan "kansantajuista". En kaipaa tieteellistä tarkastelua asialle - sille löytyy omat foorumit. Jos jutussa on selkeitä lainauksia merkitse ne, muuten ok. Tämä on kiinnostava asia jonka luulisi kiinnostavan muitakin, quantum satis on jonkun mielestä 1 ja jonkun mielestä 10 - tämän takia tätä termiä ei saisi käyttää. Olli

  5. Would there be a list of Scottish Single Malt producers/brands who do not use ANY caramel in their bottled whisky?

  6. This is great article and explains why I have had gluten reactions when drinking some distilled liquors. While the liquor is clean of gluten they are mixing in caramel coloring which have gluten. Distillers should be marking their products accordingly. Especially since they do not list ingredients.

  7. there's no gluten in the caramel

  8. Come over to Ukraine, we list the ingredients on a separate translated leaflet. I don't know why, but you guys in Europe and USA, seem not to care about the ingredients of alcohol drinks too much. Well... think twice))) In any case, whisky is a licensed hand made spirit. Make your own whisky and do not add any 150a and other E shites. Don't trust producers, they always lie in order to prosper))) you think it's air you're breathing?)))))))))

    1. The USA regulation bans the addition of caramel to it's 'straight' whiskies, like rye and bourbon whiskey.
      Ukraine is part of Europe! Though because it's not in the E.U., it would not have felt influence/pressure from E.U. food regulations, which seem to encourage some additives (natural or not, 'safety' is the issue) and discourgae others. You are right - most of the world do not seem to care about the many unnecessary additives.
      Making your own decent whisk(e)y is a skill and an art; requiring practice, knowledge and equipment, BUT it is not any where near as dangerous or difficult as is promoted by commercial spririt distillers and media alike eg. William Teacher & Sons published a book titled Make Your Own Scotch Whisky in 1972, which basically suggests that it's impossible to make scotch whisky at home by using a cartoon to over emphasize the complexity of each step. Funny reading, but serious propaganda too if you think about it!
      Anyway some caramels have been shown to have decent carcinogenic potency (cause cancer) and as such have been banned in some countries over the years, which is not surprising considering the complexity, number and type of compounds (many proven carcingens) found in caramels.
      You are also right don't trust producers, since their number one goal is to make a profit and many companies see the regulations as just their legal limits, which is all they really are anyway - not guidelines to suggest not to use some additives, but rather defined allowed substances and their limits of addition to food.

    2. I should have added in my reply above that Caramel really is widely used by the Scotch Whisky industry in a fraudulant manner in that it is used to give the impression of greater aging lengths and imply flavour (though it does add a bit itself). Yes the age on a bottle's label is true when it states 20 year or 30 year old (the min age of the whiskies in the blend), but the fact is journal research on barrel aging published decades ago by Hiram Walker & Sons showed that aging in an oak barrel really 'peaks' at something like 8 years, past which point undesirable flavours start to emerge!
      The rate of natural colour increase in the whisky derived from oak of course consistently declines over time and by 8 years is starting to become negligent, hence the IDEA of adding caramel colouring to something that's been aged 20 years, but doesn't look much darker than an 8 yr old!
      Maybe the addition of caramel helps to offset some bad flavour hints picked up in the OVER-AGED & OVER-PRICED 20 year old scotch?

      I truly beleive any spirit aged longer than about 10-12 years maximum is really an overpriced scam. In fact I'd suggest that anyone who's got that sort of money to enjoy on good spririt would do better in buying a bottle of antique whiskey aged for the correct number of years eg. a 50 or 90 year old bottle of 8 year old whisky. In fact I'd guess the caramel addition is a post WWII addition, so the really old bottles probably lack caramel and are actually just whisky - as it should be!