High gravity brewing using low gel point rice adjuncts

Beer brewed from malted barley and having a rice adjunct can be produced at higher gravity cold wort concentrations without excessive viscosity build-up by using low gel point rice.

BACKGROUND OF THE INVENTION 
This invention relates to an improved method of brewing beer from barley or 
malted barley and rice by using low gel point rice. 
In the brewing of beer by using barley or malted barley and rice, one mixes 
a main mash of malted barley and water, syphons a part of that mash into a 
rice cooker where the enzymatic action of the malt works to partially 
break down the starches in the rice while heating takes place in the 
presence of water, then pumps the partially converted rice slurry into the 
main mash tank where the mashing is completed. The insolubles of the mash 
are then permitted to settle to the bottom of the tank and the remaining 
solution or wort is strained through the insolubles, which are then 
sparged or washed and carried to the brew kettle, where sterilization by 
boiling and addition of hops takes place. The boiled wort is then cooled 
and aerated in preparation for primary fermentation. 
In the past, it has been necessary to maintain sufficiently high levels of 
water in the main mash and the rice cooker that the materials have 
workable viscosities. Otherwise, problems develop such as drive motors to 
the rice cooker and masher agitation units continually stalling, as well 
as pumps throughout the system being overloaded. 
The cumulative effect of these problems is a limited brewing capacity. That 
is, the gravity or percent solids of the wort cannot be increased 
appreciably over, for example, 15% in a given system, without encountering 
difficulty. This solids concentration is alternatively measured in what 
are called degrees of Balling. For our purposes, a degree of Balling will 
be used to mean a percent solids in the wort. 
The brewing of beer with a rice adjunct is, for the above reasons, as well 
as for reasons of raw material cost, a more expensive process than brewing 
with other adjuncts such as corn. 
SUMMARY OF THE INVENTION 
It is a main object of this invention to brew beer from malted barley and 
rice at the higher cold wort gravity of 16.degree. Balling or higher 
without cumbersome and expensive equipment modifications and without 
excessive viscosity. 
This object and other objects of the invention, which will become apparent 
from the reading of this specification and the associated claims, are made 
possible by the use of rice varieties having a gel point of 70.degree. C. 
or less. The gel point is defined as the temperature of the first rapid 
increase in viscosity and is measured by Brabender Visco/Amylo/Graph. That 
is to say, the rice is ground so that at least 25% of the material goes 
through 13 mil mesh size. One hundred grams (on a dry basis) of the flour 
is added to a 600 ml. beaker. Then 375 ml. distilled water is added, the 
pH adjusted to 6.0, then the weight is adjusted up to 500 grams with 
distilled water. The slurry is homogenized for about 1.5 minutes on a 
Lourdes homogenizer with the Variac set at 20. The pH is rechecked to be 
6.0, and the material is thereafter immediately transferred to a Brabender 
cup. The Brabender is started and heating is maintained at 1.5.degree. C. 
per minute until the maximum viscosity is reached. 
DETAILED DESCRIPTION 
Regular brew rice is usually a mixture of different rice varieties and may 
contain a large percentage of long grain, high gel point, varieties such 
as Le Belle, Le Bonnet and Starbonnet. The gel point of such rices 
previously was not of concern but is as high as 76.degree. C. 
With our discovery that paste viscosity in rice cooker is directly related 
to the gel point of the rice and that gel points of 70.degree. C. or less 
can facilitate cold wort gravities of 16.degree. Balling or higher, the 
useful rices of this invention become varieties such as Mochi Gomi, 
Brazos, Nortai, Nato and Mars. This is especially surprising in the case 
of certain of these rices such as the waxy rice varieties (Mochi Gomi), 
which are known to have such high viscosity developments that they are 
used as food thickeners and therefore do not seem likely to lend 
themselves to high gravity brewing and resolving the resultant viscosity 
problems. Other short or medium grain rices, naturally occurring, mutated, 
or even hybrids may also be useful. The gel points of rices of this 
invention usually range between 70.degree. C. and 63.degree. C. or lower. 
The rice varieties of this invention may be used alone or in combination 
with one another, or even with minor amounts of higher gel point rices, so 
long as the combined gel point does not exceed 70.degree. C.

The improvement obtained by substituting low gel point rice for regular 
brew rice in high gravity brewing is illustrated in the following 
examples: 
Production of High Gravity Wort Using Low Gel Point Rice Adjunct 
EXAMPLE I 
Preparation of 16.degree. B Wort from Mochi Gomi Rice 
Two rice adjunct brews were made in the brewhouse under identical 
conditions except the following: 
______________________________________ 
Brew A Brew B 
______________________________________ 
Malt, lbs. 24710 26355 
Rice, lbs. 10590 11295 
Rice, Kind Brew Rice Mochi Gomi 
from routine 
shipment 
______________________________________ 
Rice gel point was determined on a Visco Amylo Graph Brabender. Rice paste 
viscosity was determined on a Brookfield RV Viscometer at the end of the 
cooking cycle. 
______________________________________ 
Brew A Brew B 
______________________________________ 
Cold Wort Concentration 
15.0.degree. B. 
16.0.degree. B. 
Rice Gel Point 75.degree. C. 
64.degree. C. 
Rice Paste Viscosity 
3080 cps 80 cps 
______________________________________ 
Rice paste viscosity is not a limiting factor in the production of high 
gravity wort from Mochi Gomi Rice as exhibited by the very low rice paste 
viscosity in Brew B. It is therefore apparent that higher concentrations 
than 16.degree. B could be achieved without surpassing the 3080 cps. of a 
regular brew. 
Production of High Gravity Wort Using Low Gel Point Rice Adjunct 
EXAMPLE II 
Preparation of 16.degree. B Wort from Nortai Rice 
Two rice adjunct brews were made in the brewhouse under identical 
conditions except the following: 
______________________________________ 
Brew A Brew B 
______________________________________ 
Malt, lbs. 21350 22750 
Rice, lbs. 11350 12100 
Rice, kind Brew rice Nortai 
from routine 
shipment 
______________________________________ 
Rice gel point and paste viscosity were determined as described in Example 
I. 
______________________________________ 
Brew A Brew B 
______________________________________ 
Cold Wort Concentration 
15.0.degree. B. 
16.0.degree. B. 
Rice Gel Point 75.degree. C. 
69.degree. C. 
______________________________________ 
The use of Nortai rice at 16.degree. B presented no additional torque on 
the cooker agitator. The power consumption record showed no extra load on 
the agitator.