In Depth Baby Product Reviews Led by a Pediatrician
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If you are looking for a bottle warmer, look no further. We compared the top 8 warmers available today, putting them through extensive testing to help you choose. Since 2012, we have purchased more than 23 different warmers and used each to help you pick the right one for your family. We considered health and safety, warming temperatures and times, usability, and ease of cleaning. When you count the hours spent preparing a bottle while juggling a crying baby or multiple, having a bottle warmer that performs great while fitting with your family budget can significantly impact your daily life. Our extensive testing and ratings can help.
The Tommee Tippee 3-in-1 Advanced is a water bath warmer. We prefer water baths because we feel it is safer and more consistent than steam. The four-button interface is intuitive and straightforward and considers different variables, such as bottle type, milk temperature, and volume. The large inner chamber accommodates most wide-neck bottles, and the basket allows the lifting of shorter containers without risking burned fingers. It earned the highest overall score in our testing and is one we'd gladly use in our own homes.
The large size of the 3-in-1 Advanced may not be ideal for those who have a small kitchen or would like to use it outside the home. The warm time of the Tommee Tippee is not as fast as some others, but we gladly accept a longer wait if it means getting a more consistent milk temperature. Overall, we love this Tommee Tippee product and highly recommend it as your primary warmer.
The Kiinde Kozii is an innovative warmer that has an impressive performance to stand out from the crowd. With a top rank in our review, it quickly became a favorite at home, on the go, and at daycare. It has several notable qualities, including a user-friendly design. It accommodates all bottle shapes and materials, has a quick-start guide, a small footprint, an auto shut-off feature, and a retractable water reservoir. We like the Kozii because the SAFEHeat technology uses a warm, circulating water bath to heat bottle contents and reduce the risk of nutrient damage.
While not as speedy as steam heat technology nor as fast as many competitors, the Kozii may not be the best for everyone. Despite these minor flaws, we think it is well worth the wait to utilize the other beneficial features. The ease of use, versatility, and safety performance make it a tester favorite.
While the Kiinde warmer creates a bottle with consistent internal temperature every time, it does take longer than steam baths but it is similar to other water bath warmers.
Credit: Abriah Wofford
Compare Products
The Chicco NaturalFit Digital customizes defrost and warming time based on a container's size and type.
Credit: Abriah Wofford
Why You Should Trust Us
Having researched more than 35 warmers over time, we've tested more than 23 contenders side-by-side. We measure multiple factors such as warming temperatures, warming times, ease of use, and cleaning ease. Our extensive and detailed testing took place over several months and in various settings, including in-house at BabyGearLab, tester's homes, and daycares. Our test process includes more than 15 individual tests for temperature accuracy, temperature changes over time, and monitoring of how temperatures change over time to simulate what happens if parents forget to remove the bottle. We think the extensive heat monitoring tests are imperative to finding a safe and easy-to-use warmer. All warmers are not created equal, especially when it comes to ensuring that your precious breastmilk is not overheated. We focused on metrics such as health and safety, ease of use, warming efficiency, and ease of cleaning to find the best during our extensive testing. Our scores reveal the performance of each warmer and the differences between each.
At BabyGearLab, we provide readers with the world's most scientific reviews of baby gear. Leading our team since 2012 is founder Dr. Juliet Spurrier, a board-certified pediatrician and mother of two. Using her knowledge of all things baby and experience as a medical practitioner, Dr. Spurrier selects products with safety and efficacy in mind to develop the important metrics included in testing. Also contributing to this review is Senior Review Editor, Abriah Wofford, as well as Senior Review Editor and mother of two, Wendy Schmitz, both testing and reviewing baby gear at BabyGearLab since 2015 and 2014, respectively.
The Kiinde Kozii easily topped the rank with its user-friendly design.
The Dr. Brown's Deluxe has a removable water reservoir that can hold water for 6-12 bottle warming cycles.
Analysis and Test Results
While it isn't an absolute necessity, some parents may find having a bottle warmer is a welcome addition to the baby gear arsenal. If you have multiple babies or are only bottle-feeding, a simple, convenient, and safe option for heating your baby's meals could be a big timesaver or a stress reducer. Think of it as an extra set of hands!
While all bottle warmers can heat bottle contents, not all perform well enough to consider buying.
Credit: Abriah Wofford
Value
When preparing for a baby, costs add up quickly. Luckily, if you need a warmer, most of them are reasonably inexpensive compared to other baby gear items. The award winners in this group range in price. The top-ranked warmer, the Tommee Tippee 3-in-1 Advanced, is $43.
The Tommee Tippee Pump and Go Bottle and Pouch Warmer is a water bath warmer that works well with many bottles and storage pouches.
Credit: Abriah Wofford
Health and Safety
Health and safety should be the top priorities when choosing a bottle warmer. When warming a bottle, you should not overheat or unevenly heat the contents. Doing so can cause hot spots or alter breast milk's nutritional or immunologic value. The best way to handle breastmilk, while upholding the nutrition, is to avoid exceeding a temperature of 104 F / 40 C. Ideally, milk stays at or below body temperature, 98.6 F / 37 C.
We quickly formed preferences for specific features during testing. We became partial to products with warm water bath technology over steam heat, mainly because they aren't as hot and have a reduced risk of a scalding injury to you and your baby. Bottles tend to come out of these warmers slightly cooler and more comfortable to handle. There is also a lower likelihood of overheating internal contents.
The Kiinde Kozii and the Tommee Tippee 3-in-1 Advanced earned satisfactory health and safety scores. Both products rank among the highest of any tested products, and both utilize a water bath warming method.
Overheating Breastmilk Results in Nutrient Loss
The ideal drinking temperature for a baby's bottle will match that of your body, 98.6F/37C or less. So it is essential to pay close attention to your warming process, especially regarding breastmilk. As a living substance, breastmilk includes an incredible array of beneficial nutrients, like enzymes and probiotics, immune factors (such as IgG and IgM antibodies and immunoglobulin A), complex growth factors, and hormones.
Overheating breastmilk can cause nutritional degradation. (X-axis in minutes, Y-axis in degrees Fahrenheit)
Credit: BabyGearLab
However, as temperatures rise over 104 F / 40 C, a degradation of nutritional and immunological benefits begins. In fact, scientific studies show that both temperature and duration at high temperature is very significant. Relatively little loss of nutritional value occurs until temperatures rise above 113 F / 45 C, but the higher the temperature, the faster the degradation rate. For example, after 10 minutes at 113 F / 45 C, a study showed a loss of only about 10% of key nutritional activated enzymes. But, if you raise the temperature higher to the temperature of hot tap water in many homes (too hot for breastmilk), just a minute at 131 F / 55 C resulted in the loss of half the activated enzymes.
Bottle contents should ideally be around body temperature. Breastmilk nutrients start to degrade at temperatures above 104F.
Credit: Abriah Wofford
Basic Bottle Warming Test
We did a comparative, controlled heating test to differentiate warmers in health and safety. We determined which options were more likely to heat to recommended temperatures and successfully maintain breastmilk nutrients. We measured maximum temperatures at the manufacturer's recommended settings and fully cranked the maximum settings to account for the worst-case scenario if a user doesn't follow instructions. We also left the bottle in the warmer for up to 12 minutes to see how warm the milk gets if you forget to remove the bottle or can't get to it right away.
The chart above shows recorded temperatures every 30 seconds for a 12 minute period for warms we've tested both in this review and now discontinued. Each warmer was tested using refrigerated milk and the manufacturer's recommended settings.
Credit: BabyGearLab Staff
At recommended settings, we found that the Kiinde Kozii, and the Tommee Tippee 3-in-1 Advanced stayed below 104 degrees for the most time while still being warm enough for a baby. The Kiinde was also the fastest to reach proper warming temperatures without overheating out of these three options. The Kiinde Kozii has the lowest temperature at shut-off, and the Tommee Tippee 3-in-1 Advanced is closest to body temperature at shut-off.
The Munchkin Speed earned the lowest score for health and safety in our tests. This unit is a steam product that can cause burns if the steam makes contact with your skin. Also, if it is accidentally left in the warmer, the Munchkin Speed overheats the bottle after shut-off. It definitely heats quickly, reaching 97F in about 2 minutes. But if you are distracted by a dirty diaper or crying infant, the bottle can quickly overheat, reaching up to 137 degrees in 5 minutes and 147 degrees in 12 minutes. Both are alarming temperatures.
Overheating is Possible at Maximum Settings
In a second test, we set them to the maximum heating setting (not the manufacturer's recommended setting) to see if the warmer's misuse could result in overheating breastmilk.
We conducted a "worst-case scenario" test in which we set each bottle warmer at its maximum heat setting to see if they would overheat the milk.
Credit: BabyGearLab Staff
The Kiinde claims that they rely on a patent-pending SAFEHeat technology to prevent milk from overheating using a circulating warm water bath. However, we were able to get it to overheat in our maximum heating test. The Kiinde continued to warm at the highest setting, eventually reaching temperatures we consider to be too high. After 8:30 minutes, it crossed 104F. After 12 minutes, the milk temperature rose to 122F. We conclude that following Kiinde's recommended settings is crucial for the best results.
The Munchkin Speed is the fastest and the most likely to overheat the bottle's contents. When used at maximum heating settings (not recommended), the steam heat warmer pushed temperatures up to a scalding 150 F. This is way too hot to warm anything baby will drink, which is a severe concern for us. Even though this test used settings outside of the manufacturer's recommendation, we suspect many parents could make this mistake for the sake of time or forget the bottle is in the warmer.
All bottle contents should be tested on your inner wrist after swirling and before giving to your baby. The inside of your wrist has thinner skin and is more sensitive to temperature than your hands.
Credit: Abriah Wofford
Always Swirl
You should swirl a warmed bottle for about 30 seconds to remove potential hot spots. You MUST check the contents' warmth by putting a few drops on your inner wrist to ensure the temperature isn't too hot or too cold for your baby. The skin on your inner wrist is thin and sensitive to temperature. Milk warmed to body temperature will feel barely warm, not too warm, and definitely not hot.
The NaturalFit user interface has two options that focus on container type, bottle or food jar.
Credit: Abriah Wofford
Ease of Use
If your baby is exclusively bottle feeding, you may find yourself using a warmer every 2 or 3 hours. Having a simple, easy-to-use warmer with clear instructions can make it easier for you and other caregivers who may help you. We based our ease of use results on factors such as assembly out of the box, clear and specific instructions, quick set-up for each use, versatility, compatibility, portability, and useful elements like a water reservoir, timer, and auto shut-off.
The top-scoring warmer in the ease of use metric includes the Tommee Tippee 3-in-1 Advanced. It is simple in terms of setup and use and doesn't require much prep or maintenance. The user interface is intuitive and helpful to most people.
Each warmer requires water in the reservoir to operate correctly. Water bath warmers need more water than steam, and steam typically requires a more precise amount of water.
Filling an external reservoir is easier than trying to make precise measurements in tiny vials.
Water Reservoir
A warmer with an integrated or attached water reservoir, like that found in the Kiinde Kozii can save you time and effort. You don't need to add water with every use. Steam-based warmers require you to fill a small vial with a precise amount of water each time you use the unit. It's easy to spend almost as much time filling the vial as you do waiting for the bottle to warm, which can be tedious.
We love the warming guide on the back of the Brezza and we wish all manufacturers would follow suit with this quick reference method.
Credit: Abriah Wofford
Setting Timer and Warming Charts
Most products include charts to help you set the timer for perfect warming. These charts can range from simplistic to frustrating. Many of the instructions give directions for different bottle sizes, materials, and temperatures. Having multiple directions can complicate matters, but it is essential to consider all the variables.
We found that some products need a bit of a fiddle factor to achieve the best results. Be aware that you will inevitably go through trial and error before you consistently reach the perfect setting for daily use. However, it shouldn't take more than a day or so of fiddling to get a working mojo going with your new warmer. We appreciate that the Kiinde Kozii timer setting displays minutes. The Tommee Tippee 3-in-1 Advanced has a few more settings, but the snowflake and bottle icons make it simple to understand.
While the Orb has multiple parts to clean, the plastic parts are dishwasher safe and the chamber is easy to wipe.
Credit: Abriah Wofford
A few steam-based warmers like the Munchkin Speed include a lift-out "basket" to remove the bottle since it can become too hot to handle after a warming cycle.
Unlike much of the competition, the Tommee Tippee can easily heat breastmilk in storage pouches.
Credit: Abriah Wofford
Compatibility and Versatility
If your baby likes a certain bottle and you need a bottle warmer, you will need to ensure it is compatible with your bottle's width, height, and material. A versatile bottle warmer can be helpful if you need to switch bottle types or plan to use breastmilk storage pouches.
The orb quickly heats bottles but it lacks an audible indicator that the cycle is over and it can easily overheat contents if you leave the bottle in the chamber after the end of the cycle.
Credit: Abriah Wofford
If you are using glass bottles, make sure the bottle warmer you choose is glass-compatible.
If you are unsure what bottle your baby will prefer, go for a versatile warmer like the Tommee Tippee 3-in-1 Advanced, or Kiinde Kozii. These warmers are compatible with most bottle shapes, sizes, and materials, including breastmilk storage pouches.
Portability and Footprint
If you need to travel with a bottle warmer, have limited kitchen counter space, or want to fit your warmer inside a height-restricted area, then finding a compact warmer is essential. If you worry about height, shy away from the Baby Brezza Safe and Smart, which is taller than 10.5 inches.
The Munchkin works with a variety of bottle shapes, though taller bottles may not heat efficiently as much of the bottle will be outside the warming chamber.
Credit: Abriah Wofford
Warming Efficiency
Warming efficiency is the ability to consistently heat a bottle's contents to a similar temperature at a similar rate each time. No cooling period or shorter wait time between heat cycles is beneficial, especially if you have multiples or are in a daycare setting.
Steam heat technology helps warm bottles quickly. However, as mentioned earlier, steam heat has its drawbacks. For example, steam heat technology is incompatible with glass bottles due to breakage potential during rapid temperature changes. More importantly, steam warmers present a real risk of overheating milk if used at their maximum settings.
A removable basket is placed into the Dr. Brown's Deluxe bottle warmer for steam warming.
Credit: Abriah Wofford
With water bath warmers, the warming process takes significantly longer. The Kiinde Kozii was 80F at 5:30 minutes, and the Tommee Tippee 3-in-1 Advanced was almost 90F at 5:00 minutes. We think these longer times are worth the wait so that the bottle contents aren't too hot, and the risk of steam-related injury isn't a concern.
Thawing Breast Milk
We recommend thawing frozen breast milk overnight in the refrigerator before use. Thawing will shorten warming time, which means you'll be able to get that hungry baby drinking faster.
The Tommee Tippee warmer works with a variety of different bottle types and sizes and you can heat a second bottle immediately after the first.
Credit: Abriah Wofford
Consecutive Warming Cycle Wait-Time
While some warmers allow you to run through two back-to-back cycles, others may have recommended wait times in between use. Immediately starting another warming cycle is helpful if two or more bottles are being heated one after another. It's also handy if the first cycle doesn't get the temperature high enough for the baby's liking and you need to add more time. We found the longest wait time between use is around 30 minutes or when the warmer has thoroughly cooled. The Tommee Tippee 3-in-1 Advanced has no listed wait time, while the Kiinde Kozii has instructions to take 30 seconds off the subsequent bottle's warming time if the machine is still warm.
Given the hidden water reservoir, the Kiinde has some involved cleaning steps.
Credit: Abriah Wofford
Ease of Cleaning
Regular cleaning and maintenance are essential, but the frequency (every day vs. every use) depends on the unit. The external cleaning process typically involves a quick wipe with a dry cloth.
However, because warmers use water, mineral deposits can build up internally. These deposits mean you need to descale the units every few weeks, particularly in areas with hard water.
The descaling or demineralization process removes calcium and lime deposits that can build up on surfaces inside the warming chamber and the heating element after prolonged contact with water. Soaking the bottle warmer's internal surfaces in vinegar usually explained in manufacturer instructions, will remove deposits. The Kiinde Kozii has special instructions to soak the unit with a mild 1:50 bleach/water solution every few weeks. Some products require overnight soaking. This wait time could be a deal-breaker if you rely on your warmer for every feeding.
We also considered how difficult it is to get things very clean. Some products have hard-to-reach nooks and crannies with narrow and deep warming chambers and a poorly designed water reservoir that makes it impossible to get inside for scrubbing.
Daily cleaning of the Tommee is simple, but monthly cleaning requires a bit more effort.
Credit: Abriah Wofford
The units that scored well in this metric had fewer parts and accessories and easy-to-access water reservoirs.
The Chicco NaturalFit bottle warmer includes a removable basket insert to help ease the placing and removing of containers.
Credit: Abriah Wofford
Conclusion
Some might think that a bottle warmer is a "nice-to-have" instead of a "must-have" item in your baby's feeding gear. However, it can help create a simple and efficient feeding routine for formula or breast milk. The perks for many parents are worth the time and money to invest in a great warmer, especially for parents with multiple bottle users. To find the best bottle warmer for your needs, we put each product through extensive testing. We evaluate the safety, warming efficiency, and ease of use to gauge its functionality in the real world. We can confidently choose the top performers and make recommendations for every need and budget.
