Midwest Perlite expands perlite for a wide range of applications including horticultural, construction, industrial, and filtration. We are a family-owned and operated company since 1956. Our perlite is use by many commercial growers, agricultural companies, building material manufacturers and filtration industries and more. With our strategic location we can easily serve customers in the Midwest and central Canada.

What is Perlite and how does it work?

Perlite is a amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. 

Raw perlite ore is mined in volcanic areas, crushed, and screened into different sizes before being sent to a perlite expansion furnace. The crushed ore is then brought to a temperature (1,500°F-1,700°F) where the glass softens, and the trapped water molecules turn into steam-making the small rock particle “expand” in the same manner that popcorn expands in an air popper. The result is a particle that reveals itself under a microscope as a cluster of tiny, volcanic glass bubbles-both whole and broken.

The expanded particles that result are actually clusters of minute, lightweight, insulating, glass bubbles. Broken bubbles and surface openings on the particles provide for water and air holding capacity especially important in horticultural uses.

Sophisticated manufacturing techniques allow the expansion and collection of individual perlite bubbles, which are used as fillers or extenders for a wide variety of products.

Perlite is a versatile mineral that is mined and processed with negligible impact on the environment. When perlite ore is expanded or “popped” by rapid, controlled heating, it expands up to 15 times its original volume and takes on a foam-like cellular appearance – essentially clusters of microscopic glass bubbles, creating a porous structure. This physical transformation makes expanded perlite an extremely effective aggregate.

Many in the green community recognize perlite-enhanced products as high-performance solutions drawn from a natural material of nearly unlimited supply throughout the world.


Keith Hoople


Keith started at Midwest Perlite in high school helping his father, Gene. His early role taught him the basic principles of the manufacturing process. After high school he continued his apprenticeship full time expanding his knowledge of the comprehensive procedures of manufacturing expanded perlite. 2005, he and his wife, Julianne, purchased the company following Gene’s retirement in 2003. 

Naomi Hoople Kasuboski

Office Manager/Sales 

Naomi also started working in the family business in high school.  She started working in the office with their mother, Robyn, doing basic office duties. She left the business and worked as a dental assistant for 15 years. In 2014, she returned while she attended college to obtain associated degrees in Business Management and Marketing. After receiving her degrees, she continued to work at Midwest Perlite full time.

Joe Steiner

Plant Manager

Gene hired Joe right after high school.  Joe worked with Keith and Gene learning the ins and outs of manufacturing process. He assumed the plant manager role in 2005.  His excellent ingenuity skills make him a valuable assist to Midwest Perlite. 


4280 W. Parkway Blvd

Appleton, WI 54913

Phone: 920-731-2671

Email: sales@midwestperlite.com