Bread was a staple of army life. Each soldier was rationed 18 ounces of bread per day. There was no standard bread recipe until 1879 when the Manual for Army Cooks was released. The only regulation related to bread that appears in the 1847 regulations states that:
The troops will bake their own bread when practicable; and as the difference between bread and flour is about 331/3 percent, in favor of flour, the saving produced thereby will, with the assessment on the sutler, as mentioned above, be carried to the credit of, and constitute the post fund.
What this meant was that 18 ounces of flour was rationed to each soldier per day. But it didn't take all 18 ounces of flour to make 18 ounces of bread, so the extra flour was sold and the profits were put into the post fund.
Another guideline regarding the distribution of bread, although not officially appearing in the army regulations, was that bread was not distributed to the soldiers until it was a day old. The reason for this was that fresh bread was considered unhealthy because the yeast was still active. The army felt that the yeast would retain its activity once consumed and wreak havoc on a soldier's digestive system. After a day of sitting, the yeast would die and the bread would be fit for consumption.