How to Boil Water over a Fire

Building the Fire

Create a teepee with tinder and kindling, then light the fire. Take a few handfuls of tinder like dry grass or newspaper and place them in the center of your fire pit. Use small sticks or twigs about 1 inch (2.5 cm) in diameter for kindling and build a teepee around the tinder. Use matches or a lighter to light the tinder and get the fire started.

Add larger pieces of wood once the fire gets going. Wait for the kindling to fully catch and then add a few small logs on top. As the fire builds, gradually add thicker logs to create a solid fire full of coals you can use for boiling. Don’t add thicker logs until the smaller ones have really started to burn so you don’t smother the fire. Larger sticks are going to form the long duration or the fire, and will continue feeding small to medium sized sticks for a period of time. If you go too big with that, you're committing yourself to either a larger fire that you're probably going to have to put out before all your fuel has built out. Finding the balance is tricky, but necessary.

Wait until your fire burns down into a bed of coals. Stop adding additional logs or branches to your fire when you plan to boil your water. Allow it to burn down until it forms a nice smoldering bed of coals so you can use it more effectively. A roaring fire with raging flames won’t heat your container evenly. Besides, it’ll be tough for you to reach into it to boil your water safely. Instead, allow the fire to smolder down until it forms a nice bed of coals You want to have a small, hot fire for boiling water.

Gather the hottest coals into a circle with a stick. Find a sturdy stick or use a fire poker that you can use to safely move the coals around. Gather them up into the center of the fire and try to form a cohesive circle to help concentrate the heat. The more controlled and concentrated your fire, the more evenly it’ll heat your container. A well-controlled fire is a safe fire, and it’s easier to use for cooking and boiling.

Positioning the Container

Choose a metal pot, can, or bottle to boil your water with. Try to clear out any dirt or debris inside of it so it’s as clean as possible. You can use stainless steel, copper, aluminum, or any other metal container—just make sure it’s metal so it won’t melt. The size and shape of the container can affect how quickly the water boils. The more surface area, the faster the water heats up. Avoid using other materials like plastic or wood, which will burn before the water has a chance to boil.

Fill the container with clean water. Find a source of clean water such as bottled or from a fresh stream. Fill up your container with the water you want to boil. Never drink water directly from a stream, even if it looks clear. You need to boil it first to make sure there aren’t any contaminants that could make you sick.

Place the container directly onto the hot coals. Look for an even section in the center of the coals. Take your container filled with water and gently place it right on top of the circle of coals in the fire. Make sure it’s balanced and won’t tip over while it heats. Now, all you have to do is sit back and wait! If it helps, you can use a wet rag to protect your hand when you place the container on the coals. Be careful not to tip over the container or you could put out your fire.

Use a metal rack over the fire as an alternative. If you don’t want to get too close to the coals, or you don’t want to place your container directly on top of them, choose a steel rack that won’t melt from the heat. Set up the rack so it sits just above the coals. Then, place your container of water on top of the rack. The metal rack can serve as a makeshift stovetop. You can place pans on top and cook food over the fire as well.

Hang the container on a tripod if you have a large fire. If you’re using a big fire that hasn’t burned down to coals, take 3 sticks and tie their ends together with string or twine to form a make-shift tripod. Place the tripod over your fire and hang your container filled with water on it so it’s suspended over the fire. Your container will need a handle so you can hang it from your tripod.

Boiling the Water

Bring the water to a rolling boil. A rolling boil is a vigorous, bubbling boil that helps ensure the water is hot enough to kill any contaminants. Wait for the water inside the container to start bubbling constantly. Even if the water looks clear and it’s started to boil, it’s super important that you allow it to stay at a rolling boil to make sure it’s safe.

Let the water boil for 1 minute to kill any pathogens. Once your water reaches a rolling boil, allow it to continue for a full minute. That’ll help kill any potential pathogens in the water and make it safe to drink. If you’re at an altitude greater than 6,562 feet (2000 meters), let the water boil for a full 3 minutes.

Use a wet rag to grab the container so you don't burn yourself. Soak a cloth in water and wring out the excess. Use the damp cloth to reach into the fire and remove the container. Set the container aside and allow it to cool if you plan to drink it. You can also use the boiling hot water to make coffee or tea if you like. If you don’t have a rag, you can gather a bunch of damp leaves and use them to quickly remove the container from the fire. If your container has a handle, you can use a stick to lift it out of the fire.