Vegetable tanned leather is embraced by leather connoisseurs, skilled artisans, and us (we incorporate it into some of our products for sale). We like to discuss this multi-faceted topic, which certainly deserves your attention. Therefore, we decided to dive deep into the world of vegetable leather - covering key issues from the vegetable tanning process to sustainability in the leather industry. 
We'll start with the basics. The process of turning animal hides into leather is called tanning. Vegetable tanning is among the main leather production methods used today: approximately 10% of leather is vegetable tanned. The technique involves using natural plant tannins to alter the protein structure of leather, turning it into leather. Essentially, these organic substances perform three functions: preserving, strengthening, and coloring the leather. Tannins are commonly found (in varying concentrations) in other fruits, plant species, and seeds, where they are easily recognized due to their strong flavor. But when it comes to vegetable tanning, the barks, leaves, and roots are often preferred for their extremely high tannin concentration. A list of trees commonly used to make tan leather includes:
- Birch
- Cachou
- Chestnut
- Mimosa
- Oak
- Willow
The history of vegetable tanned leather is intertwined with the larger story of human development. One of four prehistoric tanning techniques, first used by our ancestors in Sumer (modern Iraq and Kuwait) around 5,000 years ago, the process was soaked in water filled with bark and mimosa leaves. 
The resulting leather was then used to make primitive types of clothing that kept warm and provided camouflage for hunting and bags for carrying items. Later civilizations, such as the ancient Egyptians and Babylonians, continued to make advancements in vegetable tanning, but the Romans first standardized the industry. This allowed Tuscan artisans to perfect the art of making leather sandals. The region retains a rich socio-cultural history and is still considered the heart of leather in Italy. Of course, contemporary artisans who continue to practice vegetable tanning rely on thousands of years of human experience. Stages of the vegetable tanning process:
- Curing: The skins are salted to prevent bacterial growth.
- Lime: The skins are soaked in lime milk to remove hair and greasy residue.
- De-liming: To lower the pH of hides and leathers, they are soaked in another chemical solution.
- Tanning: For 30 to 60 days, the hides are periodically moved to buckets with different concentrations of tanning solutions.
- Drying: The skins are removed from the barrel and dried for a few days.
- Treatment: The leather is oiled, stretched, cut, and measured. Other finishing treatments may also be applied depending on the use of the leather.
Hides used in leather production are a by-product of the meat industry. Once they arrive at the tannery, they should be immediately salted to prevent bacterial growth. 
The next is to remove wool, hair, and grease residue. This is achieved by "liming," which involves soaking the hides in large rotating buckets filled with natural chemicals such as milk or lime (calcium hydroxide). Before tanning begins, the pH of the hides must be lowered again. The rehydration step - called "scaling" - sends them back to the barrel, where they are treated with another chemical solution. Now that the hides are ready, they are put into buckets filled with tanning agents and water. The combination of tannins in the solution varies by tannery, and the secret is closely guarded and passed down from generation to generation. A master tanner carefully processes the mixture of tannins according to the type of leather they will produce, considering factors such as color, strength, and feel. For about a month, the skins are periodically turned in barrels containing a slightly higher concentration of tantric acid. As they absorb more and more vegetable tanning agents, the leather begins to acquire new physical properties. Once tanning is complete, the wet skins are removed and left to dry. Since all-natural fats have been lost, lubricate the leather with a mixture of conditioning oils and waxes must be lubricated. This increases color concentration and improves overall durability, reducing the risk of leather cracking in the future. Once oiled, the leather is stretched, cut, and measured. Depending on the desired finish, it can be refined even more subtly. 
Vegetable tanned leather
There are many reasons why vegetable tanned leather is considered the gold standard of the leather industry. Let us first see the favorable physical properties it possesses. Vegetarian tanned leather, in particular, is known for its toughness and resilience - it can last longer than a lifetime if properly cared for. In addition to durability, the vegetable tanning process gives the leather a unique, slightly sweet aroma, which you may already associate with leather. The absorption of tannins makes the color particularly rich and deep. Think natural, earthy tones like beige and brown. Because vegetable tanning does not require a synthetic coating, the leather can "breathe." As a result, it absorbs moisture and oils and continues to develop a "patina." In the world of leather, a patina is a sign of quality and aesthetics that can enhance the perceived value of a leather product. Part of the fun of owning a vegetable tanned leather wallet is the feeling of prestige it evokes. Knowing that the leather is made by expert craftsmen who rely heavily on centuries-old techniques is something to celebrate. Finally, vegetable tanning is the most environmentally friendly method of producing leather. More on this later, but it should be remembered that only natural and organic substances are used in the production process. Although the pros far outweigh the cons, in our opinion, there are some cons you should be aware of. The first is that, as a general rule, vegetable-tanned products are more expensive. However, it is important to consider other factors such as the premium quality, longevity, and aesthetics of vegetable tanned leather. The proverb "you get what you pay for" applies especially here. Part of the reason for the higher price of vegetable tanned leather is the longer production time (up to two months) than other types of leather. Chrome tanning is the modern method used to produce 90% leather and can be done in as little as a day. 
Regarding physical properties, vegetable-tanned leather will initially be stiff but gradually soften over time. And since it is not treated with synthetic chemicals, other leather variants usually have a higher level of water resistance. Vegetable leather is also less preferred for products requiring thin or stretchy materials. This includes clothing and car seat upholstery (the leather should stretch over the seat). As mentioned earlier, the vast majority of leather is now chrome tanned. The method was invented in 1858 to meet the growing demand for leather at the end of the Industrial Revolution. Instead of natural vegetable tannins, a solution of chemicals - mainly acid and chromium sulfate - is used for tanning the leather. The basic principle is the same (changing the protein structure of the leather), but the process is faster, cheaper, and relies more on automated machinery than manual labor. Chrome-tanned leather has its unique properties. First, because it can be dyed with chemical agents, chrome leather has more color options than vegetable tanned leather. The texture is finer and softer and is generally more resistant to heat and water - although it is also prone to cracking and less likely to have the lifespan of vegetable-tanned leather. Since chrome leather is not as porous as organically produced leather, it will struggle to patinate over time. If you're looking for that typical leather smell, you'll be disappointed (expect a chemical-infused smell or no smell). Sustainability is now a key word for players in the leather industry, and it is crucial to consider the relative impact of the two main tanning methods on the environment. Vegetable tanning is generally considered a more environmentally friendly option because it uses only natural organic substances. Vegetable-tanned leather products will naturally biodegrade over time, while chrome-tanned products will spend hundreds of years in landfills. 
A disadvantage of vegetable tanning is that it uses a lot of water. Depending on the location of the tannery, this can have a marginal or considerable impact. For this reason, many tanneries are located next to streams or rivers. However, chrome tanning poses a real risk to ecological sustainability, especially in developing countries with limited industrial regulation. The main threat comes from dumping chemical by-products - often chromium and lead - which poison rivers with carcinogens, kill local wildlife, and render farmland unsuitable for agriculture. That said, new methods are beginning to gain traction. "Chrome-free leather," although still chemically tanned, uses far less harmful chemicals for the environment. It's not hard to see the appeal of vegetable-tanned leather, from its desirable physical and structural properties to the fact that it was an ancient technique still in use five thousand years ago. I hope we've turned you into a fan - and given you a thing or two to consider on your next leather purchase.