A bottle
for the heat

Sawn is a water bottle for the sauna, made of cork and steel so it can sit in the heat with you.

The Sawn bottle: sealed cork body, cork screw lid, a thin band of steel at the neck

The sauna gives you the best twenty minutes of your day. The bottle you bring in was never built for the room.

The hottest room in your week

A steel water bottle and a paper cup sitting on a cedar sauna bench — What the heat does

Steel soaks the room in and comes off the bench too hot to hold. The paper cup gives up faster. Four minutes, and the water is warm.

A hand lifting the cork lid off the Sawn bottle, steel thread showing at the neck — What cork does, on Sawn

Cork holds the room off. After a full session on the top bench, our prototypes are still cool enough to hold.

Sawn began on a Saturday morning at a New York bathhouse, where most people drink from the paper cup the house hands you. Four minutes in the heat, and it's warm. The regulars know. Their bottles wait on the floor, or outside the door.

We walked home and spent six hours on whether it could work. Then we drew it.

The rest of that Saturday is in the build log. Start at 001 →

The first sketch of the bottle, traced from the May 23 drawing: a straight cylinder with a ribbed cork lid, a small plate near the base, and a band at the foot.

First sketch. May 23, 2026, NoHo, NYC. Still on the wall.

Why cork

The heat comes first. We believe in natural materials. Cork and steel, one clear job each. Nothing painted, nothing printed.

Cork is the bark of an oak that is never cut down. Stripped every nine years, it grows back. It is mostly air, held in millions of sealed cells, so heat crosses it slowly and water can't get into it.

Raw cork oak bark up close, pale tan with deep irregular grain — The bark itself. The tree stays standing.

Cross-section

The steel is built to keep the water cold. The cork keeps the room off your hand. Inside, two walls of stainless with a vacuum drawn between them. Nothing touches your water but steel. Outside, a shell of molded cork fixed to the steel. Not a koozie. One object.

The cross-section, as drawn.

Macro of the lid seam: cork above, a thin ring of steel thread, cork below — The same junction, up close: cork lid, steel thread, cork body.

The bottle

Cork exterior.
Steel interior.

Cold, by design

Two walls of 18/8 stainless and a vacuum drawn between them. The room has to cross steel, vacuum, and steel again to reach your water.

Cool

Cork holds the line between the room and your hand. It has spent the summer on the top bench with us.

Quiet

Wide base, low center, cork landing. Made to set down soft on the slats and stay where you put it.

The spec, as drawn

500 mlA deli bottle of water pours in exactly

18/8 stainlessDouble wall, vacuum insulated, no liner

Molded corkCork granules pressed into one shell, fixed to the steel

Cork screw lidWide mouth, food-grade silicone seal, grip ribs

Ø 85 mmOne diameter, top to bottom. 175 mm tall

Under 400 gEmpty, lid on

No paintNo powder coat, no printed logo. Etched into the cork

Hand washRinse the steel, wipe the cork

Join the

newsletter

A few hand-cut prototypes exist, epoxy seams and all. They have spent the summer on sauna benches, and they get asked about every time. Leave your email and follow the build, including the parts that fail.

Two founders, one Saturday morning, and eighteen years of friendship.

Jack

Jack builds go-to-market systems at a travel startup in New York. The first drawing from that Saturday hangs on his wall.

Solly

Solly works in finance in Toronto and is in the sauna almost every day. He asked the question: what if the bottle was made for the sauna?

They met in second grade in Vancouver and still call each other with ideas. This is the one we want to pursue.

One more cup

At the bathhouse where this started, they hand you a paper cup and a marker.

Write your name on it, leave your email, and put it on the shelf. Everyone who joins the newsletter gets one.

The bathhouse shelf

A bottlefor the heat