Effect of Mashing Temperature on the Processability of Malted Barley
MBAA TQ doi:10.1094/TQ-48-1-0816-01 |
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Reginald C. Agu. The Scotch Whisky Research
Institute, Research North Avenue, Riccarton, Edinburgh, Scotland.
Abstract
The infusion method used in mashing well-modified malt could be a
source of problems associated with malt processing. This study showed that
when well-modified barley malt was mashed at an infusion temperature of
65�C the actual internal temperature of the mash was 63�C (65/63�C). Under
this mashing condition, good results were obtained for both free amino
nitrogen (FAN) products and predicted spirit yield (PSY). Filtration rates
were also encouraging because it was possible to collect up to 250 mL of
wort in record time. Similarly, when malt was mashed at an infusion
temperature of 67�C, the actual internal temperature of the mash was 65�C
(67/65�C). Again, good results were obtained for both FAN products and
PSY, with a marginal increase of 0.5% obtained for PSY. Filtration rates
were also good, because it was possible to collect up to 250 mL of wort in
record time. A very strong correlation (R(^2) = 0.9999) was found
between filtration rates for infusion mash at 67/65�C and 65/63�C. When
the infusion mashing temperature was increased to 69�C, it corresponded to
an internal mash temperature of 67�C. Under this infusion mashing
condition (69/67�C), a marginal drop in FAN product release occurred, it
took longer than 2 h to collect 200 mL of wort, and collection of 250 mL
of wort was very difficult to achieve. Although strong correlations were
found for filtration rates of infusion mash at 69/67�C versus 65/63�C and
infusion mash at 69/67�C versus 67/65�C (R(^2) = 0.975 or 0.973,
respectively), a decline was observed compared with infusion mash at
67/65�C versus 65/63�C (R(^2) = 0.9999). The 69/67�C mashing
experiment resulted in a decrease of 0.6% for PSY. It appears that a rise
in temperature of 2 degrees Celsius in internal mash from 65 to 67�C
caused the release of materials that impeded filtration, as well as the
release of some materials that were not fermentable. Optimum results were
obtained when infusion mashing was performed at 67/65�C.
Keywords: infusion mashing, mash temperature, wort separation
rate
S�ntesis
El m�todo de infusi�n usado en la maceraci�n de
malta bien modificada puede ser una fuente de problemas asociadas con el
procesamiento de malta. Este estudio demostr� que cuando se maceraba
cebada malteada a una temperatura de infusi�n de 65�C, la temperatura
interna real del macerado fue de 63�C (65/63�C). Se obtuvieron buenos
resultados bajo estas condiciones, tanto para productos de nitr�geno
amino libre (FAN) y para el rendimiento de alcohol pronosticado
(�predicted spirit yield,� PSY). Las tasas de filtraci�n tambi�n fueron
alentadoras ya que fue posible recolectar 250 mL de mosto en un tiempo
record. Cuando se maceraba a una temperatura de infusi�n de 67�C, la
temperatura interna real del macerado fue de 65�C (67/65�C), obteniendo de
nuevo buenos resultados tanto para productos FAN como PSY (con un aumento
marginal de 0,5% para PSY). Las tasas de filtraci�n tambi�n fueron buenas,
recolectando de nuevo 250 mL en tiempo record. Se encontr� una muy fuerte
correlaci�n (R(^2) = 0,9999) entre las tasas de filtraci�n del
macerado de infusi�n a 67/65�C y a 65/63�C. Cuando la temperatura de
infusi�n se aument� a 69�C, este correspondi� a una temperatura interna
real del macerado de 67�C (69/67�C), con una reducci�n marginal de
productos FAN y una duraci�n de 2 h para recolectar 200 mL de mosto, solo
alcanzando los 250 mL con mucha dificultad. A pesar de que s� se
consiguieron correlaciones fuertes para las tasas de filtraci�n de 69/67�C
contra 65/63�C, y tambi�n para 69/67�C contra 67/65�C (R(^2) =
0,975 y 0,973, respectivamente), estos eran menores que aquella para
67/65�C contra 65/63�C (R(^2) = 0,9999). En el experimento a
69/67�C se obtuvo una reducci�n de 0,6% para PSY. Al parecer, el aumento
de la temperatura interna real de 2�C, de 65 a 67�C, result� en la
liberaci�n de materiales que impidieron la filtraci�n, as� como la
liberaci�n de otros materiales no fermentables. Se obtuvieron resultados
�ptimos a una maceraci�n de infusi�n de 67/65�C.
Palabras claves: maceraci�n de infusi�n, tasa de filiaci�n de
mosto, temperatura de maceraci�n
