Kilned caramel malts vs. roasted caramel malts
Kilned caramel malts are considerably different than their roaster produced cousins. At Cargill Specialty Malt we carry both – our own kilned products and the imported roasted products we bring in from overseas. Both methods make excellent malt, excellent but different. The type of beer you are producing, and the subsequent malt flavor profile you desire, will determine which product is most suitable for you.
Green malt is transferred to a cylindrical kiln. In the initial stages of heating, the moist air is re-circulated through the grain bed in what is called the “stewing “ phase. At high moisture levels, amylase enzymes convert a portion of the endosperm starch into sugar. After stewing, the moisture of the air is gradually decreased while the temperature is increased. Eventually 100% fresh air is drawn through the heat exchangers to facilitate final moisture removal. The temperature in the latter stages of the process is sufficient to caramelize the sugar liberated during stewing - hence the name caramel malt.
Green malt is transferred to a drum roaster. Heat is applied while the drum rotates. The roasting process begins at high moisture levels, as in the kilning process. Moisture is gradually decreased and temperature is substantially increased as the drying/color development phase proceeds. Much higher temperatures are used in a roaster, resulting in faster color development and shorter process times.
Product characteristics – kilned vs. roasted
As far as color intensity goes, C60 is C60. Regardless of the production method used, the color intensity, or the amount of color contributed by both malts will be the same. There is a difference however in the hue. Where the intensity measures how much color the malt will contribute, the hue measures which color the malt will contribute. As one would expect, the higher temperatures of the roaster contribute darker tones resulting in an overall hue one might describe as burgundy. The kiln product tends to be more of a “pure red” tone in comparison.
Given the rotating motion of the drum and the maintenance of higher stewing moisture levels, the extent of caramelization is considerably higher in roasted products – as high as 90% or more. The kilned product is more typically 30% or 40% glassy, with the balance being described as mealy. The range of caramelization within a batch of kilned product is also more variable due to the mixing dynamics of a cylindrical kiln. One can be assured that both products will be consistent in flavor and color contribution, as the overall color will be within the specification range.
The kilned product tends to contribute a caramel/toasted malt flavor. The roasted product tends to contribute caramel/sweet/very slightly roasted flavor. The one objectively beneficial flavor characteristic of the kilned product is a comparatively lower astringency contributed to the finished beer. This is primarily thought to be a result of lower process temperatures.
Product specific application
Defining the flavor and color you are looking for in your beer is the first step in choosing the most appropriate product. If one were looking for a caramelly/sweet/slightly roasted flavor and a burgundy color, a roasted caramel malt would be the best choice. If one were looking for a subtler toasted/caramel malt flavor and a distinctly red hue, the kilned product would be preferable. Distinctiveness may arguably be enhanced with the former (roasted), whereas smoothness and drinkability would be favored with the use of the latter (kilned).
Some Cargill products are only approved for use in certain geographies, end uses, and/or at certain usage levels. It is the customer's responsibility to determine, for a particular geography, that (i) the Cargill product, its use and usage levels, (ii) the customer's product and its use, and (iii) any claims made about the customer's product, all comply with applicable laws and regulations.