Best Sous Vide Gear

Developed by a manufacturer of lab equipment, the Anova Culinary Bluetooth Precision Cooker is the best sous vide gear for both professional and home cooking use. The manufacturer has a good reputation for developing precise water baths that provide accurate temperatures, just like more expensive machines designed to do similar tasks. This accurate and versatile circulator cooker, unlike other brands of clip-on sous vide cookers that we tested, has a distinct attaching technique that makes it compatible with containers of varying shapes and sizes.

Anova Culinary Precision Cooker
Jen’s Top Pick: Anova Culinary Bluetooth Precision Cooker

The lightness and ease of use of the Anova Culinary Bluetooth Precision Cooker makes it perfect for home use. It uses the Bluetooth technology to connect to smartphones, meaning the user can cook with the touch of a button. The adjustable clamp enables the device to attach onto any container, despite its shape and size. The stainless steel skirt is not just detachable, but also dishwasher-ready.

What’s more is that Anova Culinary Bluetooth Precision Cooker comes with a remote control feature to allow cooking from a remote location through a smartphone. When the cooker preheats, comes to temperature or cooking time runs out, cooking notifications are sent through the app. Moreover, the Anova accurate cooker is small in size, precise in temperature readings, affordable and versatile enough to work with containers of all sorts of sizes.

Other than its accuracy and stability, the fact that it’s stowable and flexible makes it perfect for home cooking.

For an alternative with more tank capacity and heating power, our step up pick, the Anova Sous Vide Immersion Circulator Cooker, is just perfect. It is bundled with a directional pump that operates at 360 degrees to ensure that circulation occurs at an optimal level.

Its touch screen display does not just make it easy to make temperature readings, but has the options for both degrees centigrade and Fahrenheit readouts. The temperature calibration is easily adjustable; parts that get in contact with fluid are made of stainless steel; and, for cleaning purposes, the cooker is easy to disassemble.

In case the Anova Culinary Bluetooth precision Cooker is unavailable, the Sansaire Sous Vide Immersion Circulator is a close contender based on price and performance. Although it comes with the benefits of slow cooking, small size to save space, precise results and cheaper than most sous vide cookers in the market, Sansaire is slightly more expensive.

What You Should Know before Buying (and reading on)

Before you buy a sous vide immersion circulator, you need to consider these factors or rather look out for them:
Capacity of Water Bath: sous vide equipment water bath capacities run from as low as 5l to 120l on the higher end. Note that the food pouches should have free space between them to enable circulation of water. In fact, your food pouches should fill a maximum of half the water bath. A circulator’s size, power, and water pump (used to evenly distribute heat in the bath as water circulates) determines its capacity.

Water Bath Container: whereas certain sous vide equipment come with water bath containers, others do not. Sous vide water bath containers are designed with top notch insulation materials for energy-saving purposes, and come with lids for water evaporation reduction; it is essential to minimize evaporation when cooking for more than 18 hours. However, immersion circulators neither come with lids nor are they insulated due to their versatility for use with any containers (of varying sizes and shapes).

Stable Temperatures: when it comes to sous vide cooking, even a 1 °C change in temperature can make all the difference. The best equipments for sous vide cooking are designed with ± 0.05 °C temperature stability. Thanks to immersion circulators’ water pumps for water bath circulation and electronics, they are excellent in stable temperature maintenance.

Size of the Equipment: what makes countertops and the kitchen as a whole valuable is space. Before you buy an immersion circulator, consider the amount space needed for both storage and use. Water baths controlled by all-in-one temperature gadgets are usually heavy, even during storage.

However, immersion circulators are perfect for use with ordinary cooking pots or containers, thanks to their small sizes. For instance, the Sansaire is not just budget-friendly, but perfect for a clutter-free kitchen as it occupies less space, hence can be stored even on the countertop.

Heating Power: a sous vide equipment’s heating power determines the time it takes to heat up the waater in the water bath to a particular temperature (as desired), before cooking commences.

Safety: during sous vide cooking, water in the water bath evaporates; therefore, it is essential to ensure that the water bath covers the food pouches fully. Whilst some devices are designed with lids to lower water evaporation, others simply quantify the water level and activate an alarm to notify the cook or shut the system down in case the level is very low.

Furthermore, immersion circulators are designed with protective shields to separate the pumps and heating coils from the cooking bags.
Cleaning and Maintenance: unlike immersion circulators, water ovens with controlled temperatures do not have parts that are exposed, and often come with non-stick coated surfaces; this ensures that the equipments are easy to clean and thus maintain.

Price: just like any product in the market, price is a very important factor to consider. With prices ranging from $200 to more than $1000, you can choose an immersion circulator, depending on your budget and whether you expect to use it at home, or professionally (professional sous vide cooking equipment are more expensive).

What is Sous Vide Anyway?

‘Sous vide’ is a phrase in French that means ‘under vacuum’ and entails the procedure of covering food with vacuum seals and cooking the same under controlled temperatures in water baths. However, food does not have to be vacuum sealed for you to sous vide cook. It is all about ‘precision cooking’, meaning that the technique entails heating food to a certain temperature and keeping it constant for a certain time duration for the food to cook.

Although the sous vide cooking technique was initially restricted to high end restaurants, it is currently available worldwide to chefs for the perfect level of food preparation, whilst retaining nutrients. What has made this technique available and affordable for deployment at home is the invention of various countertop equipments for sous vide cooking, such as the Anova Precision Cooker, over the last few years.

First, you need to prepare your preferred choice of food, before you can sous vide cook; it can be a chicken breast, steak, or even maize (corn) cob, whichever kind of food you wish to cook. Use a zipper lock bag or plastic vacuum sealer to cover the food fully. Set up your immersion circulator by clamping it onto a pot with water and set the temperature and time to a desired level.

Attach the food in the sealed bag to the pot with water (ensure it is fully immersed) and allow it to cook; the sous vide device ensures that the water moves around the pot at a constant temperature initially set. You can sear, serve or keep the food once it is ready. You can be sure of convenient, easy and close-to-professional top notch outcomes whenever you use your sous vide equipment to prepare a meal.

How We Picked What to Test

There exist 3 types of sous vide cookers, namely: the all-in-one water bath, which is less accurate; the immersion circulator that circulates and heats water at the same time; and the cookers that require you, the user, to bring your own device for controlling heat. The second option is the most popular amongst cooks deploying the sous vide cooking technique.

The immersion circulators are devices that attach onto the side of containers, such as plastic tubs, pots, or even coolers; other than heating water in the water bath, the devices circulate the water all around the vessels, using an impeller. The fact that the water is actively pushed around the container, guarantees an even temperature within it. Unlike other alternatives, these devices are easy to use, affordable and smaller in size.

In addition to the factors discussed under ‘what you should know before buying these devices’ above, you need to consider these attributes when searching for the best sous vide cooker:

Preciseness: for certain foods like eggs, a small change in temperature (as low as 1 degree Fahrenheit) can easily alter the expected final outcome. Therefore, you need to opt for a cooker that is not just accurate enough to offer you what you need and want, but also able to control temperature at a predetermined level (the even or constant water temperature); this ensures that the food is neither cold nor hot, having even temperature.

Speed: select a device that is capable of reaching the pre-determined temperature level within no time. The device needs to house a powerful heating coil to heat up the water fast, keeping it under the same temperature as the food cooks.

Device Stability: although the stability of the sous vide cooking gadget is essential, it is not as important as assumed. Unlike the types of food that should be cooked fast, these devices are perfect for slow and low foods, keeping focus on the target.

Built-in Timer & Color Indicator: although only certain devices come built with this feature, it is integral in sous vide cooking technique. It is perfect for tracking food being cooked, as the feature helps show the time required for the food to get ready and an alarm that goes off when a particular time period elapses (count up and down), for instance, when the cooking time ends; the downside of this is the fact that temperatures can suddenly drop, leading to growth of bacteria.

This can happen as a result of interrupted power supply in the middle of a prolonged cooking period. Although this isn’t something that occurs often, certain immersion circulators, such as the Nomiku, comes with a feature on its display that alters its color to indicate an interrupted power supply.

Calibration: when it comes to using a reputable thermometer to test your sous vide device, calibration comes in handy. The thermometer must be precise for perfect results; else things can turn out badly.

Heater: although a powerful heater can easily and promptly warm up things, it can easily blow up a fuse. However, you can boost a circulator with lower wattage by heating water in a kettle and adding in the water bath. Just like full-sized microwaves, sous vide cookers are powered at approximately 1000 to 1100 W, and 750 to 800 watts, similar to mini microwaves. Although this isn’t a deal breaker, it is worth noting in case your kitchen switches easily trip.

In addition to the factors discussed above, we also looked into other variables. What is the preciseness of the water level? How does the device attach to the container? What is the size of the device? What is the size of the needed container? Is the device noisy? Is the circulator easy to use? Does it come with an alarm? Considering these variables, you can be sure to opt for one of the best sous vide cookers in the market.

How We Tested

It is not the first time that we are testing sous vide equipment for use at home, in addition to reviewing and making recommendations. Other than figuring out the devices that are essential and those that are not, testing allows us to gain an insight onto the technological changes that have taken place over time, with regards to the cookers.

We subjected the three sous vide circulators to three main tests: the duration each took to heat a container with 3.8L of water until it hit 135 degrees Fahrenheit; the level of noise during operation; and each device’s 24-hour stability.

During testing, we also considered each equipment’s accuracy, speed to reach a predetermined temperature, and level of noise produced whilst a gadget is in use. However, testing short-term preciseness is more important than the accuracy realized in the long run. Unlike dishes, such as eggs and salmon (need less than 12 hrs cooking time), which require minimal temperature variation and 1 degree Fahrenheit accuracy, there are some foods that require at least 12-hour cooking time.

When cooking such foods over a shorter duration, let’s say 1 hour, the preciseness is very much needed. However, dishes like ribs that can take 72 hours cooking time, a degree more or less can do for preciseness purposes. Last but not least, we also looked at the energy use or drawn out by the sous vide devices.

Anova Culinary Bluetooth Anova Precision Cooker Sansaire
Temperature of Water at Start 690F 690F 690F
Time Taken to Heat 8.5L of Water to 1350F 23:36 38:14 20:41
Energy Drawn during Heating 0.41kWh 0.43kWh 0.43kWH
Energy Drawn within an Hour 0.59kWh 0.6kWh 0.55kWh
Energy Drawn within 12 Hours of Cooking 2kWh 2.04kWh 1.81kWh
Level of Sound Produced by Device 0 inches Away(47dB ambient) 64 dB 54 dB 52 dB
Level of Sound Produced by Device 12 inches Away (47dB ambient) 53 dB 50 dB 48 dB

The Best Sous Vide Gear: Anova Culinary Bluetooth Precision Cooker

Anova Culinary Precision Cooker
Jen’s Top Pick: Anova Culinary Bluetooth Precision Cooker

Due to the Anova Culinary Bluetooth Precision Cooker’s small size, affordability and flexibility, it is the apple of most home cooks’ eyes. Unlike the initial version, the cooker comes with an adjustable yet innovative clamp (attachment system), and requires less water volume in the water bath for operation, making it one of the cheapest sous vide cooking equipment in the market.

In terms of design, this cooker features an improved scroll display based on wheels; notification alarm to alert the user once the heating water hits the predefined temperature; runs quietly and comes with lower wattage circuit for energy-saving purposes. Made by a company known for its long-lasting and precise cooking equipment, the cooker is just perfect for sous vide cooking.

The small size of the device means it does not require so much storage space; it can be easily placed on the countertop without cluttering the kitchen surface. The adjustable clamp links up to a ring that can easily slide up or down to attach onto any container, irrespective of its size or shape; the ring adjusts to the length of the shaft for this to happen. The flexibility of this device with respect to its technique of attachment makes it stand out from the rest.

It is a plus that you can use all kinds of containers with this cooker; in fact, when using smaller containers, you can expect your water to hit the set temperature fast since the device is designed with a lower wattage heater. However, smaller water volume translates to less thermal mass, meaning that when cold water is topped up or items added, hence more disruption. Moreover, using less water simply means more is saved by reducing wastage.

In case you wish to view the dial from another angle, the adjustable clamp (mount) comes in handy; it allows the main shaft (column) to swivel easily. The display, a small readout based on a scroll-wheel, unlike that of the previous version of the Anova cooker, has been further simplified. You have access to two start buttons on the display: the start button for switching on the device and the start timer button that is also used to pair the cooker with a smartphone through the Bluetooth technology.

The manufacturer of this circulator reduced its wattage from 1100 W to 800W, meaning kitchen circuits are less likely to trip. Since most circuits are designed to allow 20 amp of current, they can accommodate 120V at 2400W without issues with tripping. The wattage reduction ensures that unexpected power loss whilst cooking is completely eliminated; as a result, you do not just avoid wasting food, but also minimizing the chances of having a failed cooking session.

Tested in a quiet room, the circulator produced no noise at an ambient decibel level of 47 (this is so unlike its predecessor). Using an iPhone app with low accuracy level, we tested the cooker’s volume. The cooker produced 54 sound decibels when tested 0 inches away and 51 decibels when tested about 12 inches away from the device. This is so unlike the previous version that produced 59 sound decibels and 63 decibels, respectively. Moreover, the initial version was quite noisy after prolonged cooking, producing about 72 sound (noise) decibels.

Whilst food cooks on the cooker, you can do other chores in the house, being fully aware that the alarm will go off once the predetermined temperature is hit, by sending out a notification or alarm. The cooker has also been designed to adjust the water flow direction, eliminating still water spots found in places where proper heat circulation is not taking place. The metal skirt can easily be removed to allow cleaning roles, even in dishwashers, when the worst comes to be.

The circulator is not just cost-effective and the best sous vide market cooking solution that is consumer-graded, but also comes with an adjustable clamp, in addition to accurate and constant device prices.

Other than the 1-year warranty provision for reassurance purposes, the cooker has earned several trusted reviews on Amazon, with thousands having purchased and like it.


You can easily pair the app with a smartphone through the Bluetooth technologies for remote control via the Anova Culinary free app. Whether you own an iPhone or Android (only available in the beta version), it is compatible with the Anova app. With a basic layout, the app comprises of recipes with relevant photos and are organized according to their dates of addition onto the app (can only be sorted this way). Although steak, chicken and salmon are missing from the recipes, a range of great dishes are featured.

Instead of working with ingredients to come up with proper recipes, you can easily search for the one to use in meal preparation. Power the cooker by pressing the play button, found towards the bottom of the page and set a preferred temperature (this appears at the top of the display; might be a few degree less for some seconds). Although the timer starts running the moment you start heating the water bath (instead of starting once the right set temperature is reached), this is an issue Anova is working on fixing.

However, using the iPhone version’s dial menu, you can easily set the timer and temperature manually. You have to scroll until you reach the desired time or temperature (this can be tedious); we hope that this can be improved so that a user is able to type the figures. Also, you can calibrate this circulator. Accessing the ‘calibration’ sub-menu under the settings menu pops up a warning message: “Caution: If you’re not familiar with this feature, please contact Anova support for instructions.”

The device doesn’t rely on the app entirely to function and upon selecting a recipe, the app takes care of the rest. There are third party softwares that you might prefer for use with your device, in case Anova’s app lacks certain features, such as Anova Remote for Android phone and Sous Vide 0Celsius for iPhones.

Sous Vide 0Celsius groups recipes into 3 distinct categories, namely: proteins, fruits and vegetables. Depending on how you want your finished meal and the chosen recipe ingredient’s thickness, you can alter the specified cook time. The app has an on-screen ruler that you can use to measure the thickness of your cut. For instance, whilst a 50mm thick steak cooks for 3 hours and 35 minutes at 1380 F, a 20mm cut takes 40 minutes to cook at 125.50 F.

On the flip side, the app can only signal temperature settings to the device, not the set timer. However, you can use its in-app timer, bundled with push notification. Starting out with Anova’s free official app, you can invest in this app later, if need be (if you want added features and benefits).

Since the Sous Vide 0Celsisus app does not have better control of the device, you can opt for the Anova Remote app for this functionality. You can access calibration, temperature, multi-step program setting, scroll wheel data alteration, data plot recording controls and command signaling to the device (the app warns of the device becoming non-functional due to the use of some of the commands).

However, this app does not offer calculations and recipes for precise temperatures and cooking times. Apart from not being user-friendly, this app is perfect for the adventurers and experiment-oriented cooks, who do not mind rendering the cooker non-functional.

Flaws but not Deal Breakers

Unlike the previous version, this Precision Cooker takes longer to heat water. This resulted from the device’s reduced wattage from 1100W to 800W. This also saw the price of the gadget drop. However, this is not a deal breaker because you can easily boost the cooker by preheating water in a kettle to preheat the water bath. This improves the time it takes the device to complete cooking a meal, despite being 20% slower than the previous device.

Also, there are many other company with lower wattage circulators in the market, such as the Sous Vide Supreme Demi at 550W (totally insulated and closed, so heats faster), the PolySci Discovery at 750W and the SideKIC.

The device’s simplicity is a pro, though slows down some tasks; for instance, you need to press and hold down the start button till it makes a beeping sound to change between the Fahrenheit and Celsius temperature units. Furthermore, in order to begin the timer countdown, you need to press and hold the start button for about 8 seconds, the timer icon for 3 seconds and within the scroll wheel, set the timer.

Last but not least, the Anova Culinary Precision Cooker is neither ETL nor UL certified for safety. Therefore, if safety matters to you, go for the Nomiku immersion circulator.

The Step-up Pick: Anova Sous Vide Immersion Circulator Cooker

Anova Sous Vide Immersion Circulator Cooker
Anova Sous Vide Immersion Circulator Cooker

This version of the Anova cooker is more expensive than our pick: the Culinary Bluetooth version. However, it is pretty much as good as the culinary version in terms of functionality. Rated 1kWh, the device’s heater is larger and heats water faster. The more controls on the display allow the change units, temperature and timer to be set easily; the internal thermometer can also be calibrated with ease.

Other than the ability to set temperature target, ranging from 320 to 2100F, with increments of 10F, the timer can be adjusted up or down. This version is still a good pick, offering the precision, speed, stability and power needed for sous vide cooking. The facts that it operates quietly, offers flexibility, and comes in a small size to help save storage pace, are also a plus. It is also available universally. The only reason this cooker wasn’t our pick is its higher selling price.

Budget Pick: Sansaire

Sansaire Sous Vide Immersion Circulator
Sansaire Sous Vide Immersion Circulator

With the Sansaire cooker, you can easily turn any container into a water bath for preparing some of the best meals. Due to its affordability, unmatched performance and exquisite design, sous vide cooking is not just available for the professionals in restaurant settings, but also for home-use. The device guarantees confidence and outcomes of a trained cook. Featuring a powerful heater, you can cook with temperatures on a grill, an oven or even a stovetop.

For consistent and accurate cooking outcomes, the device lets you use accurate temperature control. Other than the particular finished meal you seek, you are assured of even cooking. No overcooking, undercooking or even food getting burnt, since the food hangs in the water bath. Your meals are ready when you are ready to serve.

The Best Sous Vide Gear for Safety: Nomiku

Nomiku Sous Vide Immersion Circulator
Nomiku Sous Vide Immersion Circulator

Nomiku is not just the simplest and smallest sous vide cooking equipment in the market, but also, the safest and most powerful. This device is perfect for the user who is concerned about safety; though, its performance cannot beat that of our pick cooker. Certified by both the ETL and UL safety standard bodies, the display’s font colors change to orange to warn of a hazard, when temperatures are set below 1600F (the level advised by FDA to avoid the growth of bacteria).

Featuring a PTC heater, the cooker cannot overheat because the element is designed not to surpass a certain temperature limit. Other devices (except SideKIC), have fail safes, a feature meant to drop the prevailing temperature reading, every time the water levels drop. What makes it easy to use is the fact that it pops up warning messages every time there’s an interruption in power supply, leading to drops in water levels in the water bath.

Just like versions designed with screw-on attachment methods, Nomiku comes with a clamp coated with silicone for attaching onto the water bath (it is easier and faster to use). The adjustability of the clamp adds to its versatility, meaning it can be used with different containers. It also comes with a knob for turning on or setting the preferred temperature.

This sous vide cooking device is perfect for the safety-conscious cook. Otherwise, there are better options for making perfect meals.

Test Notes for the Long-term

We have tested and continued to make use of the Anova Precision Cooker for more than a year now. And, I am happy to say it still works quite well. Although most of our cooking is done manually, the Bluetooth feature comes handy for remote control of the device.

International Readers

Although most sous vide equipment are only designed for use in the US, those in foreign countries have a reason to smile. The Sansaire, Nomiku and 220-240V original immersion circulator and cookers, other than the 120V versions, are compatible with power ratings for many other nations, such as New Zealnd, Australia, Europe and other unknown places worldwide.

What to Look Forward to

You can expect more powerful Anova cookers with 1100W rating; Wi-Fi (would allow stolen devices to be remotely disabled) enabled devices with touch displays and features that would allow delicate foods like Tilapia to be cooked using the sous vide technology.

Nomiku also plan to unleash a Wi-Fi-enabled device funded through Kickstarter. Featuring a shorter height, new design and a rectangular shape, the device will require 1.5 inches of water only.

The Joule is expected to feature Bluetooth or Wi-Fi technology and smartphone apps. It is expected to clip onto containers of various shapes and sizes and attach to ferromagnetic vessels via its magnetic bottom. However, if your bags leak whilst cooking, you won’t be able to open up the device to the clean the pump.


There’s so much competition in this market that has seen a boom in the demand for the sous vide cooking technology.

PolyScience Sous Vide Discovery
PolyScience Sous Vide Discovery

PolyScience has the Sous Vide Discovery and the Creative in the market. Although the former device is more affordable, it is less powerful than our pick cooker.

PolyScience CREATIVE Sous Vide Gear
PolyScience CREATIVE Sous Vide Gear

The latter features a tank-like design and high accuracy, with its heavy and huge design coming as a con, making it difficult to use. atop its high price, the unit is not able to calibrate temperature.

The SideKIC is only available to certain countries, features a slow heater and requires extra accurate levels of water in the water bath. The only pro of this device was its ability to attach onto small vessels; modern versatile devices can do this and much more.

Despite its low price, our pick has better performance in terms of ease-of-use and ability to regulate consistent temperature. It comes with a small metal cage for holding food and most of its buttons barely worked when we tested this device. Its inability to maintain consistent temperature levels can totally change your cooking outcomes.

Other Frequently Asked Questions

Who Should Buy this?

Sous vide cookers for home-use are designed for experimental cooks and mainly those who love food. The devices are not just perfect for those who like trying out new recipes and different cooking techniques due to their love for cooking, but those who are patient enough to wait for hours whilst food is cooking, for the best outcomes.

This technique of cooking, sous vide, ballooned into the public eye over the previous few years. As a result of the technique’s demystifying literature and application in high-end restaurant kitchens, its demand for use at home increased (several innovators have been funding the development of affordable equipment through Kickstarter.

Currently the basis of cooking internet discussions and tv shows, sous vide entails sealing food in a vacuum, immersing it warm water till it reaches a certain constant temperature. The result of this is an evenly cooked meal that is neither over nor under cooked. Apart from being easy to follow, the cooking technique cooks tender food.

You get to minimize error margins whilst deploying this easy-to-use cooking technique for perfect dishes. The device’s preciseness and temperature controllable ability ensures that you deliver the best food outcomes. Having come down from expensive labware equipment to affordable and reliable devices, the technology has evolved over the years. And, it is always the right time to give this method of cooking a shot. Moreover, the ever increasing ease-of-use, demand and competition in this niche, has led to the availability of affordable devices.

Furthermore, there are thousands of recipes online that you can try out with this cooking technique. For instance, you can access free information on how to go about this cooking technique through the ‘Sous Vide for the Home Cook’ website, owned by Douglas Baldwin.
Focusing on the science behind sous vide cooking, the site provides information on proper handling, perfect times for cooking and several other cooking methods. Though expensive, the ‘Modernist Cuisine at Home’ and the ‘Modernist Cuisine’ websites, are home to other advanced cooking methods and the cooking science, which have been extensively researched and beautifully photographed.

What are the Benefits of Sous Vide Cooking?
Sous vide cooking eliminates overcooking and undercooking of food; this ensures that every time your food is prepared through this technique, it is perfectly done. Sous vide cooking also retains food nutrients, atop making them shelf stable. Cooking meat through this slow process subjects it to pasteurization, making slightly pink chicken and pork cuts safe for consumption.

Furthermore, the cooking process can allow you to engage in other activities with no worry of the food overcooking due to the set constant temperature.

Wrapping it Up

We recommend the Anova Culinary Bluetooth Precision Cooker if you want to give sous vide a try. It is not just affordable, precise and small, but also the most versatile cooker in the market, thanks to its adjustable clamp that allows it to attach onto vessels of varying sizes and shapes. Moreover, you can easily control the device through the free Anova app from any room within your house, not to mention its ease-of-use. Otherwise, you can consider our alternative immersion circulators.