A Tour of the Hermann Oak Tannery
A Tradition of Craftsmanship and Quality
Welcome to Hermann Oak Leather, where tradition meets craftsmanship in the art of leather tanning. For over 125 years, spanning four generations, Hermann Oak has been producing premium vegetable-tanned leather at our tannery in St. Louis, Missouri. The above video is a guided tour that offers a rare glimpse into one of the few remaining leather tanneries in the USA that still practices the traditional vegetable leather tanning process—using tannins extracted from tree bark to produce leather renowned for its firmness, workability, and natural beauty.
A Legacy Rooted in History
Hermann Oak began in 1881 as a domestic tannery supplying leather harnesses for the horse-drawn wagons heading west. While the world has changed, our tanning process as a traditional leather tannery has not strayed far from its roots. Vegetable tanning is one of the oldest chemical processes known to humankind, predating metalworking. Historians estimate that it was likely discovered by accident and refined through centuries of experimentation. At Hermann Oak, this ancient craft is carried on with care and attention to detail, producing what many high-quality leather manufacturers and artisans consider to be the best leather for equestrian gear, leather tooling, and custom crafts.
The Production of Leather: The Tannery Process
Step 1: Raw Hide Preparation
Cattle hides are removed at the packing plant, salted to preserve them, and transported to the tannery. Each hide is selected from the top 1% of available U.S. steer hides, selecting only non-branded, native, and heavyweight American hides to ensure quality. On arrival, hides are soaked to remove salt and rehydrated to their original water content.
Step 2: Cow Hide Liming and Hair Removal
The hides are treated with lime and sulfide to break down hair and open the fiber structure. This crucial step prepares the hide to absorb tannins later in the process. Excess fat is removed, and hides are then trimmed, weighed, and sorted.
Step 3: Bating and Splitting Leather
Next, hides are cleaned with traditional enzymes that were originally developed as a tanning chemical for leather processing, however they are now also used in many modern-day laundry detergents. Some hides are then split on band knife machines to achieve uniform thickness and may be shaved again later to level the grain.
Step 4: Vegetable Tanning Leather
In the heart of the hide tanning process, hides are immersed in a tanning pit filled with a custom-blended tanning solution made from tree bark extracts (oak, chestnut, hemlock). This stage, lasting four to six weeks, allows the tannins to gradually bind with the hide fibers. It is here that the unique qualities, such as firmness, molding ability, and carving potential, are permanently embedded in the leather. Unlike chrome tanning leather, which uses metal salts and takes a day, vegetable tanning is slower but results in a superior, more natural product.
Step 5: Leather Drying and Conditioning
After tanning, the leather is wrung out and stretched flat using traditional setting-out machines. Then, it is dried in temperature and humidity-controlled rooms. Known for its water resistance, harness leather is made using a special stuffing process that incorporates beef tallow in rotating drums. The tallow-rich leather is hand-set and dried for over a week, much like it was even in medieval leather tanning.
The Hermann Oak Difference
After drying, leather is trimmed, measured, and graded. Each side is pressed multiple times to smooth the grain and may be embossed or dyed depending on its intended use. For products requiring precision, hides are dry-split to exact thicknesses. The fiber layer provides strength, while the grain offers visual appeal.
Grading and Quality Assurance
Leather is graded based on its intended use. The prime area—usually the butt—is graded most strictly, as it provides material for saddle seats, holsters, and reins. Hermann Oak grades include A, B, and C, excluding poor-quality or heavily branded hides. Even top-grade hides can include minor natural imperfections such as wrinkles or healed scars—proof of the leather’s authenticity and character.
Commitment to Craft and Customer
Each order is fulfilled according to specific customer requirements, including the type of leather, grade mix, and thickness. Orders are measured with calibrated machines and hand-checked for accuracy before shipping. With over 1,000 steps and more than 100 chemicals involved in the tanning process, quality control is paramount at every stage.
The Hermann Oak Tannery is a living legacy of producing high-quality, USA leather. Our commitment as one of America's largest tanneries is one of tradition, sustainability, and unmatched quality. Whether you are a leatherworker, craftsman, or simply a lover of heritage trades, we hope these insights into our leather production process have answered any questions you might have about how leather is made.