OSU Mini Malter Project


Customer Requirements (Updated 12/06/2010)

Malter shall steep barley (Weight 10 pts.)
Steeping is the first main process in malting barley. Steeping is important to increase the moisture content of the barley so that it can begin to germinate. Steeping is conducted by immersing the grain in water for a period of time and then draining the water off for a period of time. This cycle is repeated until the moisture content of the barley is around 45%. An example steeping regime is below, but these times are adjustable.

8 hour immersion followed by a 6 hour couch (drain). Barley moisture percentage after cycle: 33%-35%
6 hour immersion followed by a 10 hour couch. Barley moisture percentage after cycle: 38-41%
4 hour immersion followed by a 2 hour final couch. Barley moisture percentage after cycle: 44-47%

Malter shall aerate steeping water (Weight 20 pts.)
Aerating the steeping water is important to remove excess carbon dioxide produced by respiration of the barley. The barley grains can also suffocate if the water is not aerated.

Malter shall allow control of inflow water temperature (Weight 20 pts.)
By changing the temperature of the inflow steeping water the time spent in the steeping phase can be shortened or lengthened. This is something that large malters cannot do, and so the sponsor is interested in seeing the effects of temperature on steeping times.

Malter shall keep steeping water temperature below 73F (Weight 20 pts.)
Keeping the steeping water below 73F is essential. If the barley reaches a temperature of 75F it will die. If the barley is killed by high temperatures the grain would have to be thrown away and the process restarted. The weighting reflects the importance of this requirement.

Malter shall couch barley (sit without water) (Weight 20 pts.)
Couching barley is important so the barley absorbs the moisture in its surroundings. This is where the barley absorbs the most moisture and so this is weighted more heavily.

Malter shall keep germination temperature below 73F (Weight 25 pts.)
The germination temperature should also not rise above 73F. Just like during steeping if the barley gets too hot it will die. Germination is when barley tends to heat up so this is an important requirement.

Malter shall keep germination temperature above 58F (Weight 5 pts.)
Keeping the germination temperature above 58F is needed so the barley can effectively germinate. If the air is too cold then the barley will not germinate. The malter will operate in room temperature surroundings and so low temperatures aren't likely.

Malter shall turn/mix barley during germination (Weight 25 pts.)
Mixing/turning the barley during germination allows for even moisture and temperature distribution. Turning also prevents the germinating barley from forming a thick mat of roots. The barley should be turned every eight hours after the initial 24 hours of germination. This first period of rest is to allow the barley to strengthen after steeping to prevent damage to the grain. Germination can take anywhere from one to four days. Mixing/turning is a critical requirement for producing a consistent malted barley and is weighted accordingly.

Malter shall allow ample adjustment of air flow rate through the grain bed (Weight 20 pts.)
Being able to vary the air flow rate is important as the germination phase and kilning phase require different air flow rates. During kilning it is also important to adjust air flow rate so that different barley malt types can be produced.

Malter shall allow ample temperature adjustment of air (Weight 20 pts.)
When kilning the malted barley, it is important to slowly ramp up the air temperature. This stops the enzymes within the barley from activating. Also, higher temperatures can be used to produce different malted barley types. Pale malts are kilned for a longer time at lower temperatures, approximately 24 hours at 100F to 120F, and darker malts are kilned at higher temperatures for shorter times.

Malter shall allow for air flow recirculation (Weight 15 pts.)
Air flow circulation will make the kilning phase more efficient in producing highly kilned (darker) malts.

Malter shall be easy to load and unload barley (Weight 10 pts.)
The customer does not want loading and unloading to be hard or take a long time. They also do not want to put any unnecessary or stress on their body.

Malter shall be portable (Weight 10 pts.)
The customer would like the malter to be somewhat portable so it can be used in classroom demonstrations, as well as moving it to other places on campus. The malter should be able to be transported by a forklift and able to pass through a standard double wide door.

Malter shall produce at least 150 lbs of malt per run (Weight 15 pts.)
The customer would like the malter to have a minimum barley processing capacity of 150 pounds. This is to allow enough malted barley to be produced to brew a batch of beer in the pilot brewery.

Construction and testing of the malter shall not cost more than $20,000 (Weight 10 pts.)
We are given a $20,000 budget and it is important that we work within this limit.