Most people have never used a wood-fired hot tub before they arrive at Opal Brook Trail. They have questions. This is our attempt to answer them honestly, without making it sound more complicated or more romantic than it is.
The basic setup ¶
Our hot tub is a 500-gallon cedar stock tank with a cast-iron firebox mounted on the outside of one stave. Cold water from the creek feeds into the bottom of the firebox, heats up, and rises back into the tank through a separate port at the top. This is called a thermosiphon, and it has been the standard method for heating water over fire for a long time. There are no pumps, no electricity, no moving parts. The water circulates by convection as long as the fire is burning.
How to stoke it ¶
We leave the firewood split and stacked next to the firebox. Start with a handful of the beeswax fire starters from the lodge store, then small splits of dry alder, then larger pieces once the fire is established. Keep the firebox door cracked for the first ten minutes to get a good draw. Once the fire is going well, close the door and open the air vent at the bottom about halfway. You are looking for a steady, moderate burn, not a roaring fire. Too hot too fast and you get uneven heating.
Why it takes 45 minutes ¶
Five hundred gallons of water is a lot of thermal mass. Even with a good fire, you are moving heat slowly through a large volume of water. The thermosiphon circulation is gentle by design. Most people find the tub is comfortable around the 40-minute mark and reaches its peak temperature (around 102-104 degrees Fahrenheit) after about an hour. If you want it ready by 8pm, light the fire at 7pm. If you want it ready at sunset, light it an hour before.
Sharing the tub with other guests ¶
The hot tub is shared between the Ridge Cabin and the Creekside Cabin. If both cabins are occupied, we ask guests to coordinate. In practice this has never been a problem. Most people end up in the tub at the same time and have a good conversation. If you want the tub to yourself, book on a weeknight when the other cabin is likely empty, or ask Margot when you book and she will tell you what is open.
A few practical notes ¶
Do not add anything to the water. No bath salts, no essential oils, no soap. The cedar tank is not sealed with chemicals and additives will damage the wood. Shower before you get in if you have been on the trail. The water is changed and the tank is scrubbed between guest stays. Bring a towel. The tub is twelve feet from the creek bank, which is beautiful but also means the ground is uneven and can be slippery after rain.
If you have questions about the hot tub before you arrive, email stay@opalbrooktrail.com. Margot will answer. It is a simple thing, built to be used, and we want you to get the most out of it.