Note 4 - Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($)	Aug. 31, 2023	May 31, 2023
Property, Plant and Equipment, Gross	$ 71,351,309	$ 70,527,909
Less: Accumulated depreciation and amortization	(38,738,203)	(37,343,203)
Net Property, Plant and Equipment	32,613,106	33,184,706
Machinery and Equipment [Member]
Property, Plant and Equipment, Gross	66,846,425	66,068,625
Plant Buildings and Land [Member]
Property, Plant and Equipment, Gross	2,364,089	2,364,089
Leasehold Improvements [Member]
Property, Plant and Equipment, Gross	1,598,738	1,553,138
Furniture and Fixtures [Member]
Property, Plant and Equipment, Gross	$ 542,057	$ 542,057