Oak bark-tanned leather soles are synonymous with high-quality handmade shoes, so it was a blow to hear in recent months of the loss of one of the oldest manufacturers of this product, J R Rendenbach in Germany. There is better news now. Production under licence for the same products with the same recipes will continue, with another German tannery, Kilger, keeping the tradition alive.

Founded in 1871 by Johann Rendenbach, a stone’s throw from the Moselle River and just 10 kilometres from Germany’s border with Luxembourg, J R Rendenbach quickly became synonymous with traditional pit-tanning, using oak bark. So much so that a trefoil of oak leaves became the company’s insignia. In a process that has remained relatively unchanged for centuries, the tanning process Rendenbach put in place requires a system of “layering”, in which hides are tanned in pits more than three metres deep, interlaced with ground oak bark. It is a slow process, traditionally taking a year and a day.

Having survived World War II, and despite the buildings being demolished by bombs, the tanning pits were unscathed. By the end of the war, production had resumed. Fast forward almost 40 years and, in 1985, Hanns Rendenbach took the company forward into the fourth generation. Modernisation was not a priority or a necessity, but diversification into cut products proved successful and, by 2007, modernisation had  brought about a full production facility for pre-assembled units such as cut soles, half soles and stack heels.

In late 2021, however, news emerged that production at Rendenbach would have to cease. With a customer base comprising a Who’s Who of handmade, Goodyear-welted shoes, this was received with obvious dismay. In the UK alone, companies such as Church, Cheaney, Edward Green and Crockett & Jones all rely on these leather soles for some of the shoes in their collections. Fifty years ago, almost all of the shoes these brands made would have been finished with a leather sole. In the last few decades, the preference for a more weather-resistant product has meant a reduction in the popularity of these soles’ and now productions equate to a 70:30 split in favour of rubber. To emphasise this point, it is a fact that over the last 15 years, Rendenbach had not lost a single customer but had seen order sizes reduce every year.

Modernisation is the key

A solution soon emerged. Some 600 kilometres away, not far from the border with the Czech Republic, on the opposite side of Germany in the town of Viechtach, sits Kilger, which has undertaken to make leather soles using Rendenbach’s recipes.

Another renowned pit tanner in its own right, Kilger has a history almost matching that of Rendenbach. With a lineage going back six generations, Kilger is no stranger to sole leather tanning. Established in 1856, the original tannery was situated in the centre of the town and supplied sole leather to local shoemakers and saddlers. By 1970 and under the control of Anton Kilger, a representative of the fifth generation, production changed direction and the focus turned to the equestrian and orthopaedic sectors, with a small line in shoe manufacture and repair. More change was to come when the tannery relocated to its current site in 2002, with its modern, purpose-built tannery remains. Having seen the direction the domestic leather industry was taking, and with great foresight it would seem, as the 300 tanneries that flourished then have dwindled to less than 30 today, Anton Kilger saw that modernisation and diversification were the key to success.

Not just with the utilisation of more modern equipment but also by constructing a modern tannery with pits above ground, allowing for easier emptying of leather and liquid, and by having a single-storey production facility, logistics were greatly simplified, and efficiencies harnessed.

Working together

Anyone who has spent time in the leather industry knows that it is not just the recipe that counts. There are many examples of tanneries that have passed on their formulations to others only for these to fail. So how does Kilger hope to maintain both the Rendenbach name and association with quality? Michael Kilger, Anton’s son and now the sixth generation to run the tannery and the driving force behind the decision to take on the Rendenbach sole business, worked alongside Hanns Rendenbach Jr for almost a year to gain an understanding of not just the formula but also the machining operations.

This was far from a hostile takeover; Hanns Rendenbach reached out to Kilger as he knew of their capabilities and a partnership was forged. Understanding the pitfalls (pun intended), Michael Kilger is aware of the task at hand and is under no illusions as to what is needed. “Our competitors say that we can’t do it like Rendenbach because we don’t have the same pits”, referring to the deep layering pits as opposed to the hanging pits Kilger currently uses. Quick to dispel this, Michael Kilger reveals that, through a close family contact who owns an old sole tannery, the right sort of pits are at the company’s disposal. The company has also bought much of the Rendenbach raw stock. “We have so many things from the Rendenbach production,” he explains. “We have the tanning liquors, the same raw material, the same bark and even the same method.” Key members of the Rendenbach team will also make the move to help maintain quality and consistency.

Outlets matter

Having a more diverse range of end uses and customers will benefit Kilger, the company believes. The ability to select raw materials for a variety of customers at an earlier stage will give an advantage that Rendenbach could never enjoy. “If you pull a batch of leather from the pits and realise the thickness is not enough for a sole leather and you only produce soles, you need to find a market for it. We can put it towards something else,” says Michael Kilger.

Room for expansion

Time will tell what physical changes might need to be made at the Viechtach tannery but for the time being we are told the current capacities seem well able to cope. The pits in the alternate location will account for the bulk of production but the building of more pits on site has not been ruled out. With regards to raw materials, there is reportedly tens of tonnes of oak bark in the Rendenbach stores, enough for a good few years’ production and with a domestic supply available, a by-product from the furniture industry, Michael Kilger is very optimistic about the message this puts out to further enhance sustainability.

It is envisaged that by February production could be under the control of Kilger and that customers will see little disruption to supply and notice little or no difference now that the product will be Rendenbach by Kilger.

Ground bark from oak, valonia and spruce are used to replicate the Rendenbach production. All credits: Kilger

Share this story: