Best Bottle Warmer

Best Overall Bottle Warmer

Tommee Tippee 3-in-1 Advanced

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$43.00

List Price

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The Tommee Tippee 3-in-1 Advanced is a warmer that heats bottles using a water bath. We prefer this method as we think it is safer and more consistent than steam. The four-button interface is intuitive and straightforward to use and considers different variables, such as bottle type, milk temperature, and the contents' volume. The large inner chamber will accommodate most wide neck bottles, and the basket allows you to lift shorter containers without risking burned fingers. It earned the highest overall score in our testing and is a device we would 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.

Read Review: Tommee Tippee 3-in-1 Advanced

Innovative Bottle Warmer

Kiinde Kozii

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$49.34

(30% off)
at Amazon

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The Kiinde Kozii is an innovative warmer with an overall performance that helped it stand out from the crowd. With the second-highest overall score in our tests, it quickly became a tester favorite at home, on-the-go, and even at daycare. It has many notable qualities, including a simple, user-friendly design. It accommodates all bottle shapes and materials, a handy quick start guide, a small footprint, an auto shut-off feature, and a retractable water reservoir. What we like best about the Kozii is the SAFEHeat technology that 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 much of the competition, the Kozii may not be everyone's first choice. However, even with these minor flaws, we think it is well worth the wait to take advantage of the other beneficial features. The ease of use, versatility, and safety make it a tester favorite.

Read Review: Kiinde Kozii

Best Bang for the Buck

Chicco NaturalFit

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$34.99

at Amazon

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The Chicco NaturalFit is a simple, straightforward warmer with a budget-friendly price. It is a safe, reliable way to heat your baby's bottle without the bells and whistles that make a product complicated or hard to use. This product uses water bath technology with a slow but consistent warmer. Its strengths lie in health and safety, ease of use, and cleaning. It is multifaceted, compatible with a variety of bottle dimensions and materials, and has a small footprint and compact volume for easy and convenient travel.

This warmer is somewhat slow and could leave your little one fussy while you wait for a warm bottle. However, we believe the lower price and consistent warming temperature are significant and overshadow the downsides, making this wallet-friendly option an excellent choice for most families.

Read Review: Chicco NaturalFit

Best for Travel

Tommee Tippee Travel Warmer

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$17.97

(10% off)
at Amazon

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The Tommee Tippee Travel Warmer is an innovative product made with on-the-go families in mind. The insulated flask stores warm water, and the extra-large beaker acts as a warming chamber that is big enough to hold most sizes of bottles, pouches, or baby food containers. To prep the warmer, all you need to do is boil water beforehand, and then all parts fit together in a self-contained unit that fits neatly in a diaper bag or stroller basket. A hot water bath brings milk to a temperature suitable for a baby without using an external warming source.

Unfortunately, due to the Travel Warmer's ultra-simplistic nature, it lacks safety features such as an auto-shutoff or end of cycle alarm. It also heats bottles slowly and somewhat inconsistently because there is no circulation. If you want movement in the water, you must swirl the beaker manually. Despite these drawbacks, if you are looking for a convenient way to warm up your baby's food while away from home, the Tommee Tippee Travel is a great potential contender.

Read Review: Tommee Tippee Travel Warmer

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

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.

Having researched more than 35 warmers, over time, we've tested more than 21 contenders side-by-side. We measure multiple factors such as warming temperatures, warming times, ease of use, and ease of cleaning. Our extensive and detailed testing takes place over several months and in various settings, including in-house at BabyGearLab, in tester's homes, and at daycares. This iteration includes 12 impressive products.

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 time saver 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

However, not all warmers are 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. All warmers were put through the wringer in comparative testing over several months, considering key operational features in day-to-day use. Our scores reveal both the performance of each warmer and the differences between each.

Value

When preparing for a baby, costs add up quickly. Luckily, if you find yourself in need of a warmer, most of them are reasonably inexpensive compared to other baby gear items. The award winners in this group range in price from $35 for the Chicco Natural Fit to $70 for the Kiinde Kozii. The top-ranked warmer, the Tommee Tippee 3-in-1 Advanced, is $43. If you aren't sure how often you will use one or even if you need one, but you want to have one on hand just in case, the Chicco is your best bet at a wallet-friendly $35. It is hard to go wrong with the Chicco. It earned a third-place rank and has a faster heat time than other award winners.

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 the nutritional or immunologic value of breastmilk. 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 certain 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 each earned a satisfactory health and safety score. Both ranked among the highest of any products we tested, 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 when it comes to 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 temperate 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

To differentiate warmers in health and safety, we did a comparative, controlled heating test. We were able to determine 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, in addition to fully cranking 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 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. Each warmer was tested using refrigerated milk and the manufacturer's recommended settings.

Credit: BGL Staff

At recommended settings, we found that the Kiinde Kozii, Tommee Tippee 3-in-1 Advanced, and the Chicco NaturalFit all stayed below 104 degrees for the greatest amount of time while still being warm enough to keep your baby happy. Out of these three options, the Kiinde was also the fastest to reach proper warming temperatures without overheating. 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, the Munchkin Speed overheats the bottle if it is accidentally left in the warmer 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 easily overheat, reaching up to 137 degrees in 5 minutes and 147 degrees at 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: BGL Staff

Once again, we were impressed with the Chicco Natural Fit, which consistently heats to safe temperatures that are neither scalding nor degrade breastmilk. Its performance in our basic test and the maximum settings test show consistency and less chance of error.

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 it is crucial to follow Kiinde's recommended settings for best results and not rely on the manufacturer's claims.

The Munchkin Speed is the fastest but also 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 end up making this mistake for the sake of time or forgetting 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

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 warmers in the ease of use metric include the Tommee Tippee 3-in-1 Advanced and the Chicco NatrualFit. Both are simple and straightforward in terms of set-up and use. They don't require a lot of prep or maintenance, and the user interface is intuitive and helpful to most people.

Water Reservoir

A warmer with an integrated or attached water reservoir, like the Kiinde Kozii, Chicco NaturalFit, or Dr. Brown's Deluxe can save you time and effort. You don't need to add water with every use. Steam-based warmers, like the Boon Orb, 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 a tedious process.

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 determine how to set the timer for perfect warming. These charts can range from simplistic and straightforward to eye-crossing and frustrating. Many of the instructions give directions for different bottle sizes, materials, and temperatures. Having multiple directions can complicate matters, but it is important to take all the variables into account.

We found that a bit of a fiddle factor is necessary to achieve the best results. Be aware that you will inevitably go through some 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 timer setting of the Kiinde Kozii displays minutes. The Chicco NaturalFit also has simple controls with a dial turned to either baby food or bottle warming. 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 and the Boon Orb include a lift-out "basket" to aid in removing 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 is attached to a particular bottle and you are shopping for a bottle warmer, you will need to be sure it is compatible with your preferred bottle's width, height, and material. Dr. Brown's Natural Flow Glass baby bottles are narrow and tall and fit well in a Dr. Brown's Deluxe warmer. However, don't expect this unit to accommodate a wide-mouth design bottle like the Tommee Tippee glass feeding bottle or the Comotomo. Some warmers are more versatile, which can be useful if you need to switch bottle types at any point 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. For example, Boon Orb is a glass no-go as rapidly rising temperatures increase breakage risk.

If you are unsure of what bottle your baby will prefer, go for a versatile warmer like the Tommee Tippee 3-in-1 Advanced, Kiinde Kozii, or Chicco NaturalFit. All three of these warmers are compatible with most bottle shapes, sizes, and materials, including breastmilk storage pouches.

Portability and Footprint

If you want to travel with a bottle warmer, have limited kitchen counter real estate, or want to fit your warmer inside a height-restricted area, a compact warmer is essential. The Chicco NaturalFit has a small footprint and doesn't have small parts that could get lost, so it is an excellent travel option. The Tommee Tippee Travel Warmer is explicitly made for an on-the-go scenario and is also one option that does not require electricity. If you worry about height, shy away from the Baby Brezza Safe and Smart, the Beaba BabyMilk, and the Dr. Brown's Deluxe, which are all taller than 10.5 inches. These warmers could struggle to fit under upper cabinets.

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 also beneficial, especially if you have multiples or are in a daycare setting.

The fastest warmers in our tests are the Dr. Brown's Deluxe and the Boon Orb. Not surprisingly, these particular warmers utilize steam heat technology, which helps them warm bottles quickly.

However, as mentioned earlier, steam heat has its drawbacks. For example, the Boon Orb's steam heat technology is not compatible with glass bottles due to breakage potential during rapid temperature changes. More importantly, steam warmers, in general, 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 the water bath warmers, the warming process takes significantly longer. The Kiinde Kozii was 80F degrees at 5:30 minutes, and the Tommee Tippee 3-in-1 Advanced was almost 90F at 5:00 minutes. The Chicco NaturalFit took a little longer with 80F at around 8:30 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.

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 cycles back to back, others may have recommended wait times in between use. Immediately starting another warming cycle is useful if two or more bottles are being heated one right after another, such as with multiples or if the warmer is in frequent use at a daycare center. It's also handy if the first cycle doesn't get the temperature high enough for 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 Chicco NaturalFit is one of these, which is a deal-breaker for some families. 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 a vinegar solution, 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, which is the case for the Chicco NaturalFit. 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—the Dr. Brown's Deluxe has a narrow and deep warming chamber 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 Tommee Tippee Travel Warmer is simple to clean and does not require descaling at all. Another is the Boon Orb, while the rest of the units finished slightly lower with similar instructions and effort levels for adequate descaling. Our least favorite to clean, and most likely to accumulate residue or mildew build-up even with regular cleaning, is the Dr. Brown's Deluxe.

Buying Advice

In our process of repeatedly testing the most popular bottle warmers over the last eight years, we've learned a lot of information we'd like to share about essential qualities and features you'll want to look for when making a purchase.

Why Purchase a Bottle Warmer?

While not necessary, if you're warming more than one or two bottles a day or your baby prefers milk to be a specific temperature, you may find it convenient to have a warmer.

The bottom line is that while it can be a convenient time-saver, a bottle warmer is not a must-have baby product. So, let's look at the alternatives side-by-side to help you assess whether the cost justifies the convenience.

Avoid Overheating Breastmilk
Breastmilk starts degrading in nutritional and immunological value at 104 F / 40 C, but deterioration accelerates as temperatures climb higher than 113F/45C. You should aim to warm baby's milk to approximately 98.6 F / 37 C (body temperature) or less.

Three Ways to Warm a Baby Bottle

It's the middle of the night. Baby is hungry, and it's your turn to feed him. Time for the midnight shuffle. Do you grab the baby and then go warm the bottle or vice versa?

Good options for warming the bottle include:

• Stand at the sink while swirling the bottle under warm tap water (not too hot)

• Put the bottle into a bowl of warm water with intermittent swirling (again, not too hot)

• Use a bottle warmer

The first two options require constant attention, which asks a lot from a half-asleep parent with a hungry, crying baby. The advantage of a dedicated warmer is that your hands are free, and you can focus on your baby's other needs like a diaper change or cuddle time.

Is it worth it? That's a personal decision, but many parents find the convenience worth the cost, especially if you plan to bottle feed or share night duties with your partner. It is well worth it to catch up on some valuable sleep.

No Microwave, No Boiling Water

You should never use the microwave to heat your baby's meal, not for formula, breastmilk, or purees. High, focused heat generated by a microwave oven can result in dangerous "hot-spots" in liquids and solids. If not correctly mixed, cooled, and checked, this can result in scalding injury to the baby. Also, a microwave is likely to heat at least some, if not all, of the breast milk above 104 F / 40 C, the temperature at which beneficial enzymes, nutrients, and antibodies begin to degrade, reducing healthful benefits for the baby.

Furthermore, putting a bottle in a pan of boiling water or just boiled water can also lead to overheating.

Selecting the Right Product

Apart from providing the convenience of being hands-free when warming a bottle, a great bottle warmer should deliver on the following five factors:

Happy baby! Nothing's better than a warm meal in the belly.

Credit: Lindsay Ellis

• Health & Safety — Avoiding the risk of burn injury and provide nutritionally whole breast milk at an appropriate temperature for the baby is essential. Generally, a good rule of thumb is to heat to near body temperature 98.5F/37C and not much higher—more on this below. We discuss how to preserve the full nutritional value of breast milk.

• Efficiency — Ability to warm contents quickly and consistently

• Ease of Use — Easy to operate and maintain

• Versatility — Accepts different shaped bottles of any material

• Portability and Footprint — Easy to transport and fits in your kitchen

Preserving Breast Milk Nutrition

As we describe in our breastmilk advice, your breastmilk is "liquid gold." Its nutritional content is invaluable for your baby, but the nutrients can be degraded by overheating.

Once you warm breast milk to temperatures higher than 104 F / 40 C, its nutritional and immunological value begins to deteriorate, both of which are crucial to a baby's health and immunity. However, degradation does not become severe until temperatures rise above 113F / 45C. For example, in a study conducted by the University of Manchester, breastmilk heated for 10 minutes at 113 F / 45 C showed a 10% loss of essential nutritional activated enzymes. And, just 1 minute at 131 F / 55 C results in a 50% loss of activated enzymes, but no significant damage occurred after 20 minutes at 104 F / 40 C (or lower temps).

Luke Warm, Not Hot
Keep in mind that the ideal breast milk temperature is around body temperature, 98.6 F / 37 C, or less, which feels lukewarm.

Some warmers have a removable basket, like this one on the Dr. Browns, that can help you avoid contact with hot water or steam.

Credit: Abriah Wofford

Options and Features

Bottle warmers come in all shapes and sizes and utilize one of two methods to prepare your baby's meal. The options include a warm water bath or steam heat. A few products offer both.

Water Bath

A water bath warms breastmilk or formula gently by circulating warm water around the bottle. They tend to heat slower but more consistently without the high temperatures required to produce steam. We recommend a bottle warmer that uses water bath technology for a few different reasons. The benefits include a gentle warming process that helps breastmilk retain maximal nutrients, maternal antibodies, and other potential health-promoting factors. We also consider it safer as the water used is only warm, not nearly as hot as potentially scalding steam.

Of the bottle warmers we tested, the Kiinde Kozii, Tommee Tippee 3-in-1 Advanced, Chicco NaturalFit, the Baby Brezza Safe and Smart, the Grownsy Fast 5-in-1, and the Philips AVENT Fast are water bath warmers.

The Speed has a few different parts including a basket and ring that can be cleaned in the dishwasher. The chamber isn't too hard to clean but you will need to do regular descaling.

Credit: Abriah Wofford

Steam Heat

To warm a bottle using steam, water inside a reservoir comes into contact with an internal heating element (such as a hot plate), which generates steam and raises the temperature inside the warming chamber. While this method is often faster than water baths, the hot water and scalding steam can rise to extremely high temperatures. The result? The bottle's exterior is often wicked hot after a heat cycle and may need to cool-down for a bit before being serviceable. If warmer contents were to spill, the risk of burn injury is possible. Steam does not always heat evenly, which means that significant temperature variations may exist throughout the contents of a heated bottle, and without thorough mixing and checking, hot-spots are a risk. In our opinion, these high temperatures carry unnecessary hazards.

Lastly, because steam heat typically generates high temperatures, there is increased potential for nutritional degradation if brought to temperatures >104F/40C. Our testing found that a few of the units make it much too easy to overheat breastmilk, resulting in a significant loss of nutrition. The warmers in our review with steam heat technology are the Munchkin Speed, Dr. Brown's Deluxe, Beaba BabyMilk, Baby Brezza Safe and Smart, and the Boon Orb.

The Tommee Tippee will fit the widest of bottles with ease.

Credit: Abriah Wofford

Versatility

Baby bottles can be narrow, wide, short, or tall, and some may not fit inside the warming chamber. Also, material limitations may mean that a certain warmer isn't compatible with a particular baby bottle. For example, you cannot use glass bottles in the Boon Orb. Also, some machines (usually steamers) only accept plastic or shatter-resistant glass because the quick heating process may cause the weaker glass to break.

If you are uncertain which bottle type and nipple your baby prefers (i.e., they haven't been born yet), we recommend choosing a bottle warmer that accommodates a larger variety of bottle sizes and materials. The Kiinde Kozii and the Tommee Tippee 3-in-1 Advanced are both excellent choices that fit every bottle and pouch we tried. The Chicco NaturalFit is suitable for different bottle types but is not compatible with breastmilk storage pouches.

The Fast has a single dial with multiple setting options and an LED indicator light to tell you when it is warming versus when the cycle is over.

Credit: Abriah Wofford

Auto Shut-Off Feature with Timer

We highly recommend buying a bottle warmer with an automatic shut off feature. Many warmers have either a timer or a temperature reading that indicates the end of the cycle. In our testing, the timer-based auto shut-offs were reliable and easy to use and read. They also allow for some personal adjustments, and once you've found the time setting that's best for your baby, it's easy to remember for next use. Plus, it's helpful to know how much longer you'll need to wait before the bottle is ready for your baby. The only warmer in our review that does not include this feature is the Philips Avent Fast.

In theory, a temperature-based shut-off is ideal. However, we found that this method didn't work very well in practice. We were often left with under-heated bottles and a few overheating incidents. The one exception is the Chicco NaturalFit, which heat consistently to an adequate temperature without going over 100F/37.8C.

End of Cycle Signal

An audible beep at auto shut-off is useful to keep parents on track. It is so easy to get distracted and lose track of time while a bottle is warming. Many of the warmers in our tests continued to warm the milk even after the auto shut-off if the bottle is not promptly removed. Because breastmilk begins to degrade significantly at temperatures above 113F/40C, preventing it from overheating is imperative.

Dr. Brown's Deluxe is a steam style bottle warmer with a side reservoir.

Credit: Abriah Wofford

Water Reservoir

Some warmers require that you add water each time, while others have a built-in reservoir that monitors the water for you and lasts through several cycles. Kiinde Kozii, Chicco NaturalFit, and Dr. Brown's Deluxe can all run multiple rounds without a refill, saving you valuable time and effort, or at least some late-night frustration.

Making Your Selection

Consider the various features and abilities each product has to help you narrow down your options. Often overlooked, small perks can make the difference between two contenders when trying to find the best warmer for your family.

The Chicco is a slow warmer on par with most water baths with an auto shut off of 5:30 minutes and a content temperature of 80F.

Credit: Abriah Wofford

Consider Warming Efficiency

Since a bottle warmer's primary purpose is to provide your baby with a comfortably warm meal, warming efficiency is a top priority. Ideally, you can toss in a bottle, tend to the baby, and return to a perfect bottle every time. Some warmers can produce consistent results every time, while other warmers vary from cycle to cycle, leaving us with an overly hot or still cold bottle. Because time is precious, a consistent warmer like the Chicco NaturalFit is a great option; it heats reliably close to the ideal temperature of 98 degrees each time. The Kiinde Kozi also warms consistently but has a lower final temperature.

With three buttons and easy to identify icons the Tommee Tippee is easy to set without the aid of a chart or manual.

Credit: Abriah Wofford

Is It Easy to Use?

Before a bottle warmer can fit seamlessly into your routine, you have to learn how to use it. The warmers in this review carry in the number of parts they include, ranging from one solid unit, like the Kiinde Kozii, to a machine with many extra pieces and accessories. Other things to consider are the setting options and heating charts. How hard are they to master? No matter what, using the warmer takes some adjustments and fiddling, but your personal operations should be as close to the instructions as possible.

The Kiinde timer knob is straightforward and a no-brainer once you "dial-in" the right time for your bottle and content temperature.

Credit: Abriah Wofford

It is inevitable that you will go through some trial and error before you consistently reach the perfect setting for the particular bottle and starting milk temperature that your baby uses most often. But it shouldn't take more than a day or so of fiddling to get your machine working correctly. Some of the easiest to use warmers are the Kiinde Kozii, the Tommee Tippee 3-in-1 Advanced, and the Chicco NaturalFit.

The water bath technology of the Kiinde is safer than steam bath warmers.

Credit: Abriah Wofford

What's Your Bottle Style?

Before choosing a warmer, think about the type of bottle you'll be using. As we mentioned above, some warmers don't fit extra-wide mouth bottles like the Tommee Tippee. Other bottle warmers, like the Boon Orb, offer adapters for wide-mouth and narrow-mouth bottles. The Kiinde Kozii, Tommee Tippee 3-in-1 Advanced, and the Chicco NaturalFit work well with all bottle types, and the first two also work with milk storage bags.

Do You Have Multiples?

Lastly, you'll want to know which warmers have a recommended wait time between running cycles. Being able to start consecutive warming cycles is vital if you need to heat two or more bottles in a row, say for twins. It's also handy if the first cycle doesn't quite get the milk warm enough, and you need to add more time. The longest wait time we found between uses was close to 30 minutes (or until the unit cools down) for the Chicco NaturalFit, while the Tommee Tippee doesn't list a wait time at all.

Can You Keep it Clean?

This metric is pretty self-explanatory but something you'll want to consider. Although cleaning isn't always a per-use or even daily requirement, cleaning is essential to keeping this product running properly. We found that unless you spill milk on the unit, cleaning comes down to proper maintenance. Since all of these machines use water in some form or another to warm the bottle, the issue lies in mineral deposits forming somewhere on the unit, usually in the warming chamber or the heating element.

Every warmer we tested instructs you to use a vinegar solution for an occasional deep clean. This process, also called descaling, gets rid of these deposits. We also found that warmers with a reservoir system carry a higher risk of mold or mildew build-up, so they should be cleaned out more frequently to avoid that possibility.

How We Tested

Our main goal while testing bottle warmers is to assess the safety and see if each could warm a bottle of milk consistently and efficiently without overheating or damaging the contents' nutritional value. We also looked for ease of use and cleaning. We tested each warmer extensively and performed hours of research to find the best products on the market.

Credit: Abriah Wofford

Health and Safety

We performed two different controlled tests of each warmer using the same protocol. We poured 4 ounces of milk into a 4 ounce Lifefactory Glass Bottle with a silicone sleeve. Each test started with milk between 42 F/5.6 C to 45 F/7.2 C. A professional-grade digital thermometer was placed directly in the center of the bottle for temperature recordings.

A common issue we anticipate is the likely event that bottles will be left in the unit after shut-down and continue heating. So, we kept the bottle inside and continued measuring temperatures every 30 seconds for a full 12 minutes.

Please note
In our tests, we use a glass bottle with a silicone sleeve, which takes longer to conduct heat than glass alone or plastic. So, our milk temperature measurements are likely to be lower than if you use a plastic bottle. However, the times are still accurate relative to one another and give a good indication of which warmers heat faster than others.

Manufacturer Warming Recommendations

Following the manufacturer's recommendations, we tested the bottle contents for each warmer every 30 seconds. We also noted the milk's temperature at the time of auto-shutoff. If there is no auto-shutoff feature, we took a final temperature recording at 12 minutes.

Boon Orb Warming Guide

Credit: BabyGearLab Staff

Maximum Heat Settings

We also tested each product by cranking a room temperature warmer to its maximum settings, using the same set up of 4 ounces of refrigerated milk in a Lifefactory glass bottle and the included sleeve. We recorded temperatures every 30 seconds for a maximum of 12 minutes.

Why did we do this?

We don't condone stepping outside the manufacturer's instructions, but let's face it, not everyone is going to play by the rules. We suspect, when faced with a crying baby, some parents will attempt to heat the bottle as fast as possible. In this event, we wanted to see how high the temperatures ascended with each warmer running at full-throttle.

The small graduated tube is difficult to measure due to very small increments so pouring out and starting over happened a lot.

Credit: Ruth and Ben Traxler

Ease of Use

For ease of use, we considered how simple it is to set up the product right out of the box, the number of pieces, ease of day-to-day operation, and the clarity of the instructions. We carefully read the directions, reviewed the initial assembly, and then took notes on how easy it was to use daily. Over the course of several months, we considered elements such as the clarity of the warming chart, the ease of adding water, and whether a caregiver could use the unit without significant coaching.

Warming Efficiency

To evaluate warming efficiency, we used 99℉ as our ideal standard milk temperature. Reason? That is roughly the temperature of milk coming straight from the breast, and we assume this is the ideal temperature for feeding a baby. During these tests, we took into account auto shut-off time and warming wait time as well.

Manufacturer Recommendations: Auto Shut-Off Time & Temperature

Following each manufacturer's warming recommendations, we recorded the time and temperature at auto shut-off.

Chicco NaturalFit's warming instructions specify that the device needs to be fully cooled before subsequent use (see bottom sentence); in our experience, this took between 15-30 minutes.

Credit: BabyGearLab Staff

Consecutive Warming Wait Time

The last factor in warming efficiency is the consecutive warming wait time. We took a look at how quickly you can restart the warmer to heat a second or third bottle. Some products require you to let the machine cool completely, while others simple ask that you reduce the warm time of the next bottle. This information comes in handy if you have more than one child to feed, or are using the warmer in a daycare setting.

Ease of Cleaning

Each product we tested has a manufacturer recommendation to wipe-down all surfaces at least every other day. They all require occasional descaling for removal of hard mineral deposits to keep in good working order as well. The frequency of descaling can vary from product to product and may depend on the water hardness in your home.

The Chicco NaturalFit bottle warmer includes a removable basket insert to help ease the placing and removing of containers.

Credit: Abriah Wofford