Cost of revenues of Shiitake increased by $4,953,975, or 39.1%, to $17,639,983 for the year ended September 30, 2021 from $12,686,008 for the year ended September 30, 2020. The increase was primarily attributable to the increase in sales volume from 1,227 tons for the year ended September 30, 2020 to 1,515 tons for the year ended September 30, 2021, which resulted in an increase of $3,154,787 in cost of revenue of Shiitake. Also, the increase was caused by an increase in average unit cost of Shiitake from $10,327 per ton for the year ended September 30, 2020 to $11,642 per ton for the year ended September 30, 2021, which resulted in an increase of $1,799,188 in cost of revenue of Shiitake. The increase in sales volume of Shiitake was mainly attributable to the recovery of market demand for our Shiitake products since the containment of major COVID-19 outbreak in PRC in April 2020 as well as an increase in one new customer which contributed $2.6 million in cost of revenues of Shiitake. The increase in average unit cost of Shiitake was mainly due to the increase in the raw material price as a result of lower harvest in 2021 and, since July 2021, we have been purchasing packaged Shiitake instead of raw materials from our suppliers, the cost of purchasing packaged Shiitake tends to be higher than raw materials.
Cost of revenue of Mu Er increased by $4,289,277, or 42.4%, to $14,406,483 for the year ended September 30, 2021 from $10,117,206 for the year ended September 30, 2020. The increase was primarily attributable to the increase in sales volume from 1,000 tons for the year ended September 30, 2020 to 1,205 tons for the year ended September 30, 2021, which resulted in an increase of $2,258,549 in cost of revenue of Mu Er. The increase in sales volume of Mu Er was caused by the increase in market demand for Mu Er as a result of the recovery of market since the containment of major COVID-19 outbreak in PRC in April 2020 as well as an increase in one new customer which contributed $3.1 million in cost of revenue of Mu Er. Also, the increase in average unit cost of Mu Er from $10,106 per ton for the year ended September 30, 2020 to $11,948 per ton for the year ended September 30, 2021, which resulted in an increase of $2,030,728 in cost of revenue of Mu Er. The increase in average unit cost of Mu Er is in line the increase in the price of raw materials due to lower harvest in 2021 and, since July 2021, we purchased packaged Mu Er instead of raw materials from our suppliers, the cost of purchasing packaged Mu Er tends to be higher than raw materials.
Cost of revenue of other edible fungi and agricultural products increased by $1,224,877, or 134.7%, to $2,134,204 for the year ended September 30, 2021 from $909,327 for the year ended September 30, 2020. The increase was mainly attributed to the increase in sales volume from 43 tons for the year ended September 30, 2020 to 5,587 tons for the financial year ended September 30, 2021. We sold 5,572 tons of corn to two new customers and the cost of revenue was $1.8 million for the financial year ended September 30, 2021.
Gross profit
The following table sets forth the breakdown of the Company’s gross profit from continuing operations for the years ended September 30, 2021 and 2020, respectively:
| | | | | | | | | | | | | | | | |
| | Years Ended September 30, | | Variance |
| | 2021 | | % | | 2020 | | % | | Amount | | % | |
Shiitake | | $ | 2,854,379 | | 55.9 | % | $ | 2,412,869 | | 51.9 | % | $ | 441,510 | | 18.3 | % |
Mu Er | | | 2,118,240 | | 41.5 | % | | 1,965,159 | | 42.2 | % | | 153,081 | | 7.8 | % |
Other edible fungi and other agricultural products | | | 136,662 | | 2.7 | % | | 273,394 | | 5.9 | % | | (136,732) | | (50.0) | % |
Total | | $ | 5,109,281 | | 100.0 | % | $ | 4,651,422 | | 100.0 | % | $ | 457,859 | | 9.8 | % |
Overall gross profit from continuing operations increased by $457,859, or 9.8%, to $5,109,281 for the year ended September 30, 2021 from $4,651,422 for the same period of the last year. Gross profit from sales of Shiitake increased by $441,510, or 18.3%, to $2,854,379 for the year ended September 30, 2021 from $2,412,869 for the year ended September 30, 2020. Gross profit from sales of Mu Er increased by $153,081, or 7.8%, to $2,118,240 for the year ended September 30, 2021 from $1,965,159 for the year ended September 30, 2020. Gross profit from sales of other edible fungi and agricultural products decreased by $136,732, or 50.0%, to $136,732 for the year ended September 30, 2021 from $273,394 for the year ended September 30, 2020. The increased overall gross profit was caused by increased sales for the year ended September 30, 2021, as compared to the prior period.
Overall gross margin from continuing operations decreased by 3.4 percentage point to 13.0% for the year ended September 30, 2021 from 16.4% for the year ended September 30, 2020. Overall average unit margin decreased from $2,061 for the year ended September 30, 2020 to $615 for the year ended September 30, 2021. The decrease in overall gross margin was mainly attributable to gross margin of corn was 3.2% and gross margin of Shiitake and Mu Er was 0.7% for a new customer which caused the decrease in overall gross margin.