Nassenheiders

Please order in multiples of 2 units. That is how they are packaged at the factory, with 46 evaporators packed per carton. Please note: the evaporator is sold without 65% Formic Acid. Click here for Formic Acid.

Take control of hive health effortlessly with the Nassenheider Professional Evaporator. This long-term evaporation system is designed for safe and effective treatment in beehives. Perfect for autumn (and spring) use, it utilizes a 65% formic acid (FA) solution for consistent evaporation over a 20-day period when using the No.2 wick. Beehives with high pest pressure can be brought into balance in a relatively short space of time. In areas with high re-infestation issues, it is recommended to do 2 treatments. For treatments in summer or during a honey flow, we recommend using Oxalic Acid Extended-release (OAE) strips.

Key Benefits:

• Cost-Effective Hive Care – A reliable, long-term solution that reduces expenses.
• Healthier Bees – Clients report reduced symptoms of chalkbrood and nosema after a 20-day FA treatment.
• Boosted Honey Yields – Stronger colonies mean better honey production.
• No Resistance – Nowhere in the world have pests grown resistance to these natural products – Formic Acid, Oxalic Acid or Thymol.
• Proven over Many Years – European beekeepers have been using natural products for over 40 years.
• No Residues – Formic Acid and Oxalic Acid leave zero residues in the comb.
• Less Sugar Feeding – Healthier bees naturally gather more food during the off-season.
• Simplified Safety – Easy-to-follow procedures minimize risks when handling formic acid. 65% FA is safer to handle than common off-the-shelf 84% FA.

Product Features:

• Complete Kit: Includes the evaporator, 250ml bottle, and three wick sizes for adjustable evaporation rates.
• No. 1 Wick: Very slow evaporation and suggested for use in nucleus colonies.
• No. 2 Wick: Ideal for single brood box colonies, evaporating 250ml of FA in approximately 18 days. Filling the bottle to the top (≈290ml) lasts around 20 days — about 14ml/day.
• No. 3 Wick: Recommended for double brood box colonies. One of our tests in Jan 2025 showed 250ml evaporation in 7 days (≈36ml/day).
• Versatile Design: The evaporator requires a 75mm spacer rim located directly above the brood box. 90mm top feeder rims or empty supers can also be used. 

Extra 250ml Nassenheider bottle? Click Here.

Replacement Wick & Cloth Set? Click here.

Need a rim? Click Here.

Want mesh on the bottom of the rim? Shop Here

Evaporation Rates:

With 65% Formic Acid, it is recommended to evaporate between 9 and 22 millilitres per day per full-depth brood box. 22ml per day in one brood box is at a level where it is thought to disrupt pests under the cell cap. However, that high level of exposure is not necessary for good control. 14ml per day will eliminate virtually all phoretic pests (those on adult bees). Drone cells are capped for 14 days, so as long as there is continuous application for at least 15 days, effective control can be achieved.

Safety

Formic Acid liquid, and the gas from the liquid, can damage skin and eye tissue. It is very important that suitable protective clothing is worn. This is especially important when filling bottles from bulk containers. A respirator mask with face protection, nitrile gloves, PVC apron, and overalls should all be worn. Replacing empty bottles with full bottles in the field requires nitrile gloves as a minimum. Stand upwind when performing this procedure.

Field-Tested Results:

In a Featherston field trial, where autumn hive health management was historically challenging, the Nassenheider Evaporator delivered outstanding results, significantly improving colony strength and overall health. Read the full blog HERE.

Usage Tips:

• Assemble evaporator parts with the desired wick size.
• Spread the fleece cloth in the tray and secure it with the clips provided. Double up the cloth at one end so the post for the bottle clamp is not covered.
• Fit the bottle holder onto the post.
• In an outdoor location and with suitable protective clothing, fill the bottle with 250ml of FA and secure the lid for safe transportation.
• At the apiary site, place the tray on top of the brood nest.
• Remove lid from bottle and screw on the evaporator while the bottle is vertical.
• Check the screw connection for tightness to ensure safe operation.
• Place the bottle with evaporator into the bottle holder. See video for more info.
• Fit a 75mm rim to surround the evaporator. Fit hive mat and lid. 
• For creative beekeepers: Cut old full-depth boxes into three rims and paraffin-dip them for sterilization.
• Top Tip: Extra bottles can be purchased separately here. Fill hundreds of bottles safely, then fit them to evaporators in the field as required. The beekeeper is exposed to minimal FA and only needs protective gloves — similar to handling Formic Pro pads.
• NB. If your beehive has a vented base, it is recommended to block the vents and leave the front entrance fully open for best results.

For more info and FAQ: Click here.

Why Choose Nassenheider?

Engineered for performance and safety, the Nassenheider Professional Evaporator is trusted by beekeepers to protect their hives effectively. With 46 units per carton, stock up for your apiary or share with fellow beekeepers. Order in multiples of 46 for the best value!

Use with 65% Formic Acid: Available here.

Make your varroa treatments more efficient with this spare 250ml bottle, designed to use with the Nassenheider Professional Evaporator. This is ideal for beekeepers who want to perform a second treatment without needing to refill the original bottle or those who prefer to pre-fill multiple bottles before heading to the apiary.

Key Benefits:

• Convenience: Pre-fill bottles in bulk for quicker and safer hive visits – simply swap them over when needed.
• Efficiency: Saves time by eliminating the need to refill in the field.
• Reduced Exposure: Minimizes handling of formic acid at the hive site, reducing beekeeper exposure.
• Ideal for Second Treatments: Perfect for areas with high varroa reinfestation where two treatments are recommended.

How It Works:

1. Pre-Fill Safely – Fill multiple bottles with 250ml of 65% Formic Acid in a safe environment.
2. Transport Securely – The sealed lid prevents spills during transport.
3. Quick Swap – At the hive, simply remove the used bottle and attach the pre-filled spare.
4. Resume Treatment – Ensures a smooth continuation of varroa control without downtime.

A simple, cost-effective upgrade for serious beekeepers using the Nassenheider Evaporator.

To order Nassenheider Evaporator: click here.

Order now to streamline your varroa treatments.

65% Formic Acid – Ready for Nassenheider Evaporators

Important: Formic Acid can't be shipped to rural addresses. See shipping details at the bottom of this page or contact us to discuss your options. Shipping may take a few extra days.

Temporary Shipping Delay: We are currently experiencing delays of 2 to 3 weeks for delivery. We appreciate your patience while we resolve this.

For Use with Nassenheider Evaporators

This 65% Formic Acid solution is prepared for use with the Nassenheider Professional Evaporator, enabling slow and consistent evaporation over approximately 20 days. Designed for easy handling and consistent performance in temperature-controlled applications.

Key Features:

• Pre-Mixed 65% Solution – No dilution or mixing required
• Steady Release Profile – Suited to devices such as the Nassenheider Evaporator
• Available in Two Sizes – Choose between 1.15kg bottles or 23kg drums
• Compatible with Common Application Devices – Used in both professional and hobbyist settings

Available Sizes:

• 1.15kg Bottle – Ideal for small-scale applications
• 23kg Drum – Suitable for bulk or repeated use

Application:

Add the required amount to your Nassenheider Evaporator following the manufacturer’s instructions. Evaporation may occur over a period of approximately 20 days depending on environmental conditions. Always follow all safety and handling guidelines.

Safety Guidelines:

• Wear protective gloves and safety goggles when handling
• Use in a well-ventilated area away from heat and sunlight
• Keep out of reach of children and animals
• Store upright in a cool, dry location

Shipping Information

Formic Acid is classified as a Dangerous Good (DG), and special transport conditions apply:

1.15kg Bottles:

• Ships via courier to urban addresses only (no rural delivery)
• Up to 6 bottles can ship in one parcel for the same DG charge

23kg Drums:

• Must be shipped via truck to urban business addresses only
• Freight costs are better value for 4+ drums per shipment

Freight Estimation:

After adding items to your cart, proceed to checkout to view the estimated shipping cost. If the rate looks high, return to your cart and submit a quote request for a more accurate freight price.

Need help? Contact us for assistance with bulk shipping or delivery options.

⚠ Disclaimer

This product is not advertised or sold for any agricultural compound use as defined under the ACVM Act 1997, including but not limited to the treatment or control of Varroa mites. If you require a registered product for such use, please consult an appropriate registered compound or seek professional advice.

Nassenheider Replacement Wick & Cloth Set

Keep your Nassenheider Evaporator performing at its best.

Over time, the wick and blue cloth in your Nassenheider evaporator wear down, leading to inconsistent evaporation and reduced treatment effectiveness. This genuine replacement set ensures your evaporator continues to deliver reliable formic acid application for effective Varroa mite control.

Features:

• Genuine Nassenheider replacement parts

• Includes wick and blue cloth

• Easy to install

• Ensures consistent evaporation and optimal mite treatment

• Compatible with Nassenheider Professional Evaporator

Replace worn components regularly to maintain the efficiency and safety of your Varroa treatments.

Add to your next order and keep your gear in top condition.

Find the Nassenheider Evaporator here.