Aufguss in the sauna: what it is, how it works, etiquette

An Aufguss is the steam round of a sauna session: water is poured on the hot stones of the heater and the hot air is pushed towards the people sitting, usually with a towel. The German dictionary Duden defines it exactly that way: pouring water on the hot stones of a sauna to raise the humidity of the air. For a few minutes the heat feels stronger, even though the thermometer barely moves.

I'll take you through where the word comes from, how it runs in a spa, what happens to your body, the etiquette to follow and how to do it at home without damaging the heater. One thing up front: it does not detox you and it is not a therapy. It is the most intense moment of the session, and should be treated as such.

What Aufguss means

Aufguss is a German word with two meanings, and Duden lists both. The first is an infusion, the liquid you get by pouring boiling water over leaves or herbs. The second is pouring water on the hot stones of a sauna (Duden, entry Aufguss, in German). In English it is usually left untranslated, or called a steam infusion.

In Finland the same thing has another name, löyly, and a different weight. UNESCO, which in 2020 added sauna culture in Finland to its list of intangible cultural heritage, puts it at the heart of the experience: löyly is «the spirit or steam released by casting water onto a stack of heated stones» (UNESCO, Sauna culture in Finland). The same entry counts 3.3 million saunas for 5.5 million inhabitants.

The difference between the two words is one of usage. Löyly is the steam, which in a home sauna everyone makes for themselves. Aufguss, in German-speaking countries and in the spas that have adopted the habit, has become a small ritual led by one person.

How an Aufguss works in a spa

At an announced time the person leading it, the sauna master or Aufgussmeister, comes into the cabin. They pour water on the stones, often scented with an essence, and then move the air with a towel to carry the steam to the benches. Everyone seated stays still and quiet until the end.

In Germany the national sauna association has a guideline for Aufguss rounds in saunas open to the public. The main requirements, presented by the association at a seminar of the German statutory accident insurance (Pieper, Deutscher Sauna-Bund, 2018, in German):

• trained staff and one person responsible for the Aufguss rounds
• no more than one Aufguss per hour for each member of staff
• 20 to 30 grams of water per cubic metre of cabin
• 90 °C measured at the ceiling
• before starting, information for guests on duration, the essence used and the option to leave

The same presentation includes a survey of operators: 65% run an Aufguss every hour, the average temperature reported is 88 °C, and in 90% of cases the safety information is given before starting. The last figure is the one that concerns you: leaving during an Aufguss is expected, it is not bad manners.

What happens to your body during the steam round

In a Finnish sauna the air is dry: relative humidity usually sits between 10 and 20%, at 80 to 100 °C. Throwing water on the stones raises humidity and temperature for a short time (Laukkanen and colleagues, Mayo Clinic Proceedings 2018;93:1111).

Sweat is there to cool the body, and it does so by evaporating. With more vapour in the air it evaporates less well, so the heat feels stronger: this is why the steam round feels like a jump in temperature even when the thermometer has hardly moved.

You can see it with a hygrometer in the cabin, checking it before and after the round: a thermometer with hygrometer starts at € 84.

What an Aufguss does not do is detox you. A review of sweat physiology says so explicitly: direct evidence that sweating is an effective method of detoxification is lacking, and for heavy metals the main route of elimination is the gut, not the skin (Baker, Temperature 2019;6:211). Sweating more for a few minutes means losing more water, which you need to replace by drinking.

Aufguss etiquette in five rules

They apply in spas, where the cabin is full and someone is working for everybody.

• Go in before it starts. Opening the door halfway through lets the steam out and disturbs those already inside.
• Towel under your whole body, feet included, as in any session.
• Stay quiet while the person leading is working.
• The first few times, lower bench and near the door. The lower bench is the coolest part of the cabin, and from there you can leave without climbing over anyone.
• If you feel unwell, leave at once, even halfway through. Health comes before etiquette, and the German guideline requires guests to be told they can.

The general rules of the cabin, from swimsuits to phones, are in the guide on sauna etiquette.

How to do an Aufguss at home

In a home sauna an Aufguss is done on a small scale. You need a wooden bucket and ladle, a towel and clean water. If you do not have them, our wooden bucket and ladle set starts at € 128.

The dose is worked out from the volume of the cabin. A BL-180 Finnish sauna with 3 seats measures 150 by 150 centimetres and is 200 high: that is about 4.5 cubic metres. At the 20 to 30 grams per cubic metre of the German guideline, that makes between 90 and 135 grams of water, in other words one ladle. It is the same normal dose given in our usage sheet, 100 to 150 ml.

The same calculation for the three sizes of our Finnish saunas:

Two ladles are also the most the sheet allows at once, so the largest cabin is the only one where you reach the limit. In the smallest, half is enough.

The sequence:

1. Bring the cabin up to temperature and fill the bucket.
2. Pour the dose on the centre of the stones, slowly and at arm's length, never on the edges or the heating elements. The steam rises at once at more than 100 °C: the safety sheet asks you to keep one metre away while pouring.
3. Wait 5 to 10 seconds for the steam to rise, then move the towel in wide sweeps, from the ceiling towards the benches, keeping it at least 50 centimetres from the heater. A towel resting or dropped on the heater is a fire risk.
4. Stay seated as long as the heat is pleasant, then leave and cool down.

The sheet gives one round every 5 to 10 minutes and never more than two ladles at once: too much water cools the stones and can damage the heating elements. In a session of 10 to 15 minutes that means one or two rounds, not one straight after the other. The water has to fall on the stones, which must cover the heating elements: if yours are worn, replacement lava stone starts at € 84.

On essences the rule is strict: only oils made for saunas, 3 to 5 drops per litre of water, mixed in the bucket. Never neat on the stones. The sheet also rules out pouring beer, wine, perfume and salt water: they damage the heating elements and leave smells and deposits. The full procedure is in the Finnish sauna usage sheet, and times and cycles are in the guide on how to use a Finnish sauna.

When not to do an Aufguss

An Aufguss is the hottest moment of the session, so everything that rules out the sauna applies. Our safety sheet rules out use with a fever above 37.5 °C, acute infections, a recent heart attack, unstable angina, severe heart failure, uncontrolled epilepsy and acute venous thrombosis; during pregnancy it rules it out in the first and third trimesters, and in the second allows it only with your obstetrician's approval. With high blood pressure, even when treated, and with medication that affects temperature regulation, it asks for a doctor's approval first. The full list is in the Finnish sauna safety sheet.

The review cited above lists unstable angina, recent heart attack and uncontrolled high blood pressure among the contraindications to sauna bathing. With a heart or blood pressure diagnosis, the question goes to your doctor first, not to the sauna master.

The first few times you can skip the Aufguss: go in once the round is over, or stay on the lower bench. With children in the cabin the sheet asks for reduced temperatures and short times, and a steam round goes in the opposite direction: I would not do one.

Leave at once if you feel dizzy, nauseous, get a strong headache, a racing heart or difficulty breathing. If the symptoms do not pass after 10 to 15 minutes of rest, call a doctor.

Frequently asked questions

What is an Aufguss?
It is the steam round of a sauna: water is poured on the hot stones and the hot air is moved with a towel towards the people sitting. For a few minutes humidity rises and the heat feels stronger.

What does Aufguss mean?
It is a German word. The Duden dictionary gives it two meanings: an infusion, and pouring water on the hot stones of a sauna to raise the humidity of the air.

What are the benefits of an Aufguss?
I have not found studies measuring effects specific to the Aufguss. What it does is raise humidity and perceived heat for a short time, and many people find it the most enjoyable moment of the session. It does not detox you: evidence that sweating detoxifies is lacking.

Does an Aufguss have contraindications?
The same as the sauna, all the more so because it is the hottest moment. Our safety sheet rules out use with fever, acute infections, a recent heart attack, unstable angina, severe heart failure, uncontrolled epilepsy and acute venous thrombosis. With any health condition or treatment, your doctor decides.

What is an Aufgussmeister?
The sauna master, the person who leads the Aufguss: they pour the water and move the air with the towel. The guideline of the German sauna association requires trained staff.

Can you do an Aufguss in a home sauna?
Yes, on a small scale: from half a ladle to two depending on the volume of the cabin, never more and never on the heating elements. Then you move the air with a towel, keeping it away from the heater. One or two rounds per session are enough.

Are Aufguss and löyly the same thing?
Almost. Löyly is the Finnish word for the steam released by pouring water on the stones. Aufguss is the German word for the same gesture, which in spas has become a ritual led by one person.

What to do, in order

1. In a spa, go in before the Aufguss starts, and the first time sit on the lower bench near the door.
2. Leave whenever you want: it is expected, and at the first sign of feeling unwell it is the thing to do.
3. At home pour the dose for your cabin on the centre of the stones, at arm's length: from half a ladle to two, never more and never on the heating elements.
4. Wait 5 to 10 seconds, then move the air with the towel, 50 centimetres from the heater.
5. Use only diluted sauna oils, 3 to 5 drops per litre. No beer, perfume or neat oils.
6. Drink after the session and, with a heart or blood pressure condition, ask your doctor first.

The most common mistake is pouring more water in the belief that it gives more effect: beyond two ladles the stones cool down and the heating elements can be damaged. The next step, if you have a sauna, is to try a single round and watch the hygrometer.

The models are in the Finnish saunas category, and four questions about your space and how you will use it narrow down the catalogue. To try one before deciding there are 231 venues across 194 towns, arranging the visit with the venue. For anything else there is our customer support, and who we are is on the about us page.

Catalogue figures in this guide (dimensions, seats and prices) are read from the product pages and update with the catalogue: what you see is the current value. The cabin volume and the water dose derived from it are our own calculation based on the external dimensions. Doses, times and limits of use come from the technical documentation of the cabins we sell, refer to a healthy adult and do not replace the instructions for your model. The information on effects and contraindications reports what the cited sources say, is for general information and does not replace medical advice: if you have a health condition, are pregnant, are on treatment or have doubts about your condition, consult your doctor before using a sauna.