Nassenheiders

Nassenheider Professional Evaporator - Advanced Varroa Control

Please order in multiples of 2 units. That is is how they are packaged at the factory, with 46 evaporators packed per carton.

Take control of varroa mites effortlessly with the Nassenheider Professional Evaporator. This long-term evaporation system is designed for safe and effective varroa treatment in beehives. Perfect for autumn (and Spring) varroa control, 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 infestations can be brought under control 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 Varroa Control – 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 varroa mites grown resistance to these natural products - Formic Acid, Oxalic Acid or Thymol.
• Proven over many years – Europe have been treating mites with 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. If filling the bottle to the top = 290ml and will last approx 20 days. 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. 

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 mill per day per full depth brood box. 22 mill per day in one brood box is at a level where it is thought to disrupt the mites under the cell cap. But that high level of exposure is not necessary for good mite control. 14 mill per day will kill virtually all the phoretic mites. (Mites on bees) Drone cells are capped for 14 days so as long as there is an application killing virtually all phoretic mites for a continuous 15 day period then good varroa control can be accomplished.

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. It is especially important when filling bottles from the bulk supply 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 doing this procedure.

Field-Tested Results:

In a Featherston field trial, where autumn varroa control was historically challenging, the Nassenheider Evaporator delivered outstanding results, significantly reducing mite levels and improving colony health. Read the full blog HERE.

Usage Tips:

• Assemble evaporator parts with 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 250mls 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 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 in a safe manner & location then fit them to the evaporators out in the field as required. The beekeeper is then exposed to very little FA and only needs to wear protective gloves. Very 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 for 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.

Order now to streamline your varroa treatments.

65% Formic Acid – Ready for Nassenheider Evaporators

Important! - Note shipping details at the bottom of this page.

Reliable and effective varroa mite control – 65% Formic Acid is a trusted treatment used in beekeeping to combat varroa mites. Specially prepared for use with the Nassenheider Professional Evaporator, this solution delivers consistent vaporization over 20 days, ensuring healthier, stronger colonies.

Why Use 65% Formic Acid?

• Effective Varroa Control – Targets mites in capped and uncapped brood.
• Proven Beekeeping Treatment – Used worldwide to support colony health.
• Long-Term Vaporization – Works over 20 days when used with the Nassenheider Evaporator.
• Ready to Use – No mixing required, ensuring ease of use and safety.

Available Sizes:

• 1.15kg Bottle – Ideal for small-scale or hobbyist beekeepers.
• 23kg Drum – Perfect for commercial beekeepers or bulk users.

Application:

Simply fill your Nassenheider Evaporator with the appropriate amount of 65% Formic Acid and allow it to evaporate gradually over 20 days for optimal varroa control. Always handle with care and follow safety guidelines.

Important Safety Information:

• Use protective gloves and safety glasses when handling.
• Store in a cool, well-ventilated area away from direct sunlight.
• Keep out of reach of children and pets.

Shipping Information:

Formic Acid is classified as a Dangerous Good (DG), which means special shipping conditions apply. The shipping cost varies depending on the quantity purchased, but bulk orders offer better value.

1.15kg Bottles:

• Ships via courier to urban addresses only (no rural delivery available).
• Up to **6 bottles** can be shipped in one parcel for the same shipping cost.

23kg Jerry Cans:

• Must be shipped via truck to urban business addresses only.
• Shipping is high for just one unit, but the cost stays the same for up to 4 jerry cans in the same shipment and then it increases with more than 4

Getting the Shipping Rate:

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

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