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Menthol crystals or sauna oil

Updated: 21 October 2026

You are choosing between a jar of crystals and a bottle you pour, and both are filed under sauna infusion. Menthol crystals or sauna oil is a real fork: CozyNature is solid menthol, and Wellow, frihed or Baldini is a scented liquid with a different dose. A poured oil is the better buy when you want peach, citrus, pine or a Demeter line rather than a cold mint hit. The product table is on [Organic sauna infusion](/hub/steam-baths/organic-sauna-infusion). If you buy through our amazon.co.uk links, we may earn a commission at no extra cost to you. Captured listings and UK shop instructions are from 19 October 2026.

You are choosing between a jar of crystals and a bottle you pour, and both are filed under sauna infusion.

Our top picks

Wellow Wellow blood orange rosemary

Best overall

Wellow Wellow blood orange rosemary
10.0/10about £16.82
View offer
CozyNature CozyNature menthol crystals

Best value

CozyNature CozyNature menthol crystals
9.4/10about £8.95
View offer
Baldini Baldini Blue Mountain

Alternative

Baldini Baldini Blue Mountain
8.4/10about £9.91
View offer
On this page
  1. 1.They are not the same ingredient
  2. 2.Strength and how long the pack lasts
  3. 3.Heat, postage, and the heater
  4. 4.When to buy the oil instead

They are not the same ingredient

CozyNature, model CN-S-MC-100-SNL, is 100 g of menthol crystals at £8.95. The listing says the menthol comes from the mentha plant and claims it is vegan and free from additives. The dose is 1–3 crystals, dissolved in the infusion or used in a vaporiser bowl. That is a solid. It is not a diluted mint oil. A poured concentrate here is a liquid. Wellow is blood orange and rosemary, dose 5 ml. frihed peach says a few drops. Baldini is eucalyptus, rosemary and peppermint with Demeter wording and no dose printed. None of those is a jar you count in pieces. A crystal will feel colder and harsher than a drop of peach oil. It will not smell of blood orange, cedar or Baldini’s blend. Herb bags and Sedum’s 45–50 ml extracts are other formats, on the sauna infusion buying guide.

Strength and how long the pack lasts

Avena tells you to dissolve 1–2 small crystals in about a litre, never dry on the stones. Saunainter’s Yeti page says 1–2 crystals in water above 38°C. Saunamenthol says start with 1–3 crystals about 0.5 cm. CozyNature’s bullet is 1–3. Start with one if the jar is new. You can add a piece next time. Price per gram misleads. You do not use 100 g in an evening, and you do not use 100 ml of Wellow if you follow 5 ml. The jar is the better buy only if menthol is the smell you will finish. One stored note says the crystals dissolved poorly.
Wellow Wellow blood orange rosemary

Testsieger

Wellow Wellow blood orange rosemary
10.0/10about £16.82
View offer

Heat, postage, and the heater

Stored CozyNature texts mention crystals melting in warm weather, so a jar in a hot car or the sauna room can fuse into one lump and the 1–3 piece dose becomes a guess. Saunamenthol puts the melt near 41°C. That is a brand figure, not a statute. Keep the jar cool between sessions. The listing says dissolve the crystals. It does not say to put them dry on the stones. One review describes a flare on a charcoal burner when crystals were misplaced. That is one report, not a test, and it is the wrong trial for an electric element. Dissolve first, then ladle. The pour, including hot versus cold water, is on how to use sauna infusion. Skip the jar if you have asthma, you are pregnant, or strong mint already bothers your chest or eyes. Avena and Saunamenthol print those cautions. They are not an NHS ruling on this ASIN.

When to buy the oil instead

Buy the oil when you do not want menthol. Wellow is blood orange and rosemary at £16.82, dose 5 ml, with two German reviews. frihed peach at £14.75 says a few drops. Baldini is the Demeter eucalyptus blend. The captured price is £9.91, a same-day snippet showed £19.82, and there is no dose. Recheck the live price. Buy the crystals if you want that mint, you will dissolve 1–3 pieces, and you accept that 1,792 ratings are not a UK-written panel. Skip them for a fruit, forest or Demeter scent. CozyNature leaves the steam-room question blank, and so do the oils.

Common questions

Are menthol crystals just mint oil?
No. CozyNature is solid menthol, not a blended sauna oil. Baldini is a liquid eucalyptus blend with Demeter wording and its own missing dose. A crystal is stronger piece for piece than a drop of those oils. You dissolve it. You do not pour it on the stones as if it were oil.
How many crystals versus how many drops?
CozyNature says 1–3 crystals. Avena says 1–2 small crystals in about a litre. frihed says a few drops. Wellow says 5 ml. Start with one crystal. Do not convert pieces into drops. If the room is already too strong, another ladle will not undo it.
Will a 100 g jar last longer than 100 ml of oil?
Only if you stay at a low count and you want menthol each time. At 1–3 crystals, 100 g is a long supply. Wellow at 5 ml is about twenty intense sessions from 100 ml, fewer if you use less.
Why did the crystals arrive as a lump?
Warmth. Review texts mention melting in warm weather, and Saunamenthol puts the melt near 41°C. The jar can fuse in the post. Break off a piece only if you can still judge one crystal. If you cannot, do not tip an unknown chunk into the bucket.
Can crystals catch fire?
They can flare on a burner if they are not dissolved. One review describes that on charcoal. Avena says never dry on the stones, and Saunamenthol warns about electric elements. That is not a lab test. Dissolve 1–3 crystals, then ladle.
Are the 1,792 reviews British?
The line is 4.6 from 1,792 on amazon.co.uk. None of the first 50 stored texts is marked United Kingdom. Use them as comments on strength and melting. Do not call them 1,792 British customers.
When is a poured oil the better buy?
When you want blood orange, peach, pine or Baldini’s Demeter blend rather than menthol. Also when you will not dissolve a solid, or you do not want a dry-crystal fire note in the cabin. You still dilute the oil. Neat oil on the stones is a separate mistake.

Related pages

Best sauna infusion

Organic sauna infusion

Sauna infusion buying guide: the four bottle formats

How to use sauna infusion: dilute it, then one ladle

Sauna oil in a steam room needs the maker's own fluid

Sources

Public UK and maker sources named below. amazon.co.uk prices, stars and review counts are from the twelve listings in this comparison, captured on 19 October 2026. Page updated 21 October 2026.

  1. Harvia, sauna-water perfumes only (retrieved 19 October 2026)
  2. Harvia, 0.2 litre ladle (retrieved 19 October 2026)
  3. HSE, GB CLP downstream user (retrieved 19 October 2026)
  4. General Product Safety Regulations 2005 (retrieved 19 October 2026)
  5. ASA / CAP, Health: Aromatherapy (retrieved 19 October 2026)
  6. Kyrra FAQ (retrieved 19 October 2026)
  7. Avena menthol crystals (retrieved 19 October 2026)
  8. Business Companion, candles and diffusers (retrieved 19 October 2026)