Cold-smoking is a slow process. The smokehouse behind Thorn Panel Line runs between 18 and 22 degrees Celsius, which means the food inside is not cooking. It is absorbing smoke over a long period. The fuel source determines the character of that smoke, and we have used bincho-tan charcoal since the smokehouse was rebuilt in 2016.

What Bincho-Tan Is

Bincho-tan is a dense, hard charcoal made from ubame oak, traditionally produced in Wakayama prefecture. It burns at a very high temperature with almost no smoke of its own, which makes it an unusual choice for a smokehouse. We use it not as a smoke source but as a heat source. It provides a steady, controllable base temperature without introducing its own flavour compounds into the chamber.

The Role of the Cherry Wood

The smoke itself comes from cherry wood, which we source from a supplier in Nara. Cherry wood produces a mild, slightly sweet smoke with a clean finish. It does not have the resinous quality of some hardwoods, which can leave a bitter aftertaste on cured meats. For the miso-cured ham, where the miso is already doing significant flavour work, a clean smoke is essential. The cherry note should be present but not dominant.

Temperature Control in Summer

Maintaining a cold-smoke temperature in a Kyoto summer is harder than it sounds. The ambient temperature in July and August can reach 36 degrees Celsius, which means the smokehouse needs active management to stay below 22 degrees. We run the smokehouse at night during the hottest weeks and monitor the internal temperature every two hours. This is one reason the summer run of miso-cured ham is limited to twelve pieces: the smokehouse cannot safely handle more in peak heat.

The Rebuild of 2016

The original smokehouse, built when the shop opened in 2011, was too small and had poor airflow. The smoke was uneven and the temperature fluctuated by as much as eight degrees across the chamber. We rebuilt it in the autumn of 2016 with better insulation, a revised airflow design, and a larger bincho-tan bed. The difference in consistency was immediate. The first batch of miso-cured ham from the new smokehouse was the best we had made.

What This Means for the Food

Cold-smoking at a controlled temperature over forty-eight hours produces a different result from hot-smoking or short cold-smoking. The smoke penetrates more evenly, the surface does not form a hard crust, and the interior retains its moisture. For the smoked duck breast, which is brined overnight before smoking, the result is a slice that is supple and even throughout, with no dry edges.

The smokehouse is cleaned and restocked on the first Tuesday of each month. If you have questions about the process, the counter is the right place to ask.