by Jean Francois on Apr.12, 2012, under
Published March 2nd 2012
- Size and weight: Polyscience SV Professional is more heavy compared to SV Chef of Vacstar. Proportions and design of both circulators are very similar. You can say Vacstar was not really inspired when copying Polyscience’s design. Even small details are similar but the finishes of VcaStar are not neat and the quality of the plastic used by Polyscience is far better. The big difference in weight could be explained by a more powerful motor used by Polyscience to mix water.
- Tank/vessel capacity: Polyscience and Vac-Star have designed their immersion circulator for a similar vessel capacity (20 L). Polyscience indicates SV Professional can stabilise water up to 30 L.
- Safety: a float switch is the best solution to alert cooks when the waterlevel is too low and pouches risk to float at the surface. SV Chef of Vac-Star benefits from this safety device, Polyscience don’t. The float switch of Vacstar is made of plastic and foam (see picture) that looks cheap compared to the metal float switch proposed by other trademarks. The overheating protection of Polyscience has not been implemented for food safety reasons but to protect the machine against fire in the case of low waterlevel. We made a test removing water below the “min” water level until the pump was not runing in water anymore. The SV Chef of Polyscience was still running and keeping the coil temperature as close as possible to the target temperature.
- Temperature stability: Polyscience SV professional has an exceptional stability (± 0.06°C) which can be achieved especialy if containers are well insulated. Vac-Star SV Chef is using an On/Off controler as discussed in this interesting Egullet forum. This “technology” is wellknown since Seattlefoodgeek.com blog has developped a $85 DIY immersion circulator. Some well informed poeple on Egullet pointed out that such equipment can’t last long because of a mecanical relay that could break : “… Assume a 1 million cycle life and 10S period. Relay life would be 1M cycles * 10S period/ 3600S/Hr = ~3000 Hrs of operation. Maybe longer if you increase the period or start skipping cycles entirely when you reach equilibrium… if you use a relays it will not break for some time when controlled “correctly” (though even 3000h are not that much considering the 72h cooking marathons those device have to withstand). I would not use one because of the scenario that might happen when the relays malfunctions and gets stuck, and the heating element run continuously on full power”…
- Ease of use, comfort, silent: both immersion circulators are easy to use. Polyscience doesn’t have a timer. Vacstar has one but it is not really user friendly. Buttons of Vacstar are a bit too small in my opinion. Polyscience SV Professional is loud because of its big motor while Vac-Star SV Chef is silent but less powerful.
- Maintenance, cleaning: immersion circulators must be frequently cleaned to remove the limescale appearing after some days of intensive use on the grid and heating coil. A sous vide pouch could also break during cooking process (badly sealed pouch). You need a screw driver to open the plastic grid and clean the device. The VacStar SV Chef is a little bit less practicle to open and to close compared to Polyscience. In my opinion both Polyscience and Vacstar heating coils are not easy to clean. The float switch of VacStar is cheaply made of plastic and foam. If not cleaned often this float switch may get stuck.
- Warranty: 1 year.
- Price: SV Professional of Polyscience is twice more expensive compared to SV Chef of Vac-Star (EUR 625 excl.VAT EUR compared to 285 excl. VAT).
- Polyscience immersion circulator is well designed and a wellknown American trademark. It contains the state of the art PID controler and gives a great feeling of confidence when having it in your hands. On the other hand SV Professional doesn’t have a timer, a float switch and is made of plastic, probably for costs reasons.
- Vac-Star has launched the cheapest immersion circulator available on the market but can’t be compared, in terms of technology and quality, with Polyscience. It works fine but it seems the technology used by VacStar to control the temperature (a mecanical relay) has a limited life expectancy.
by jean-francois on Aug.22, 2011, under
Sous vide equipment manufacturers or distributors are always presenting their products in the best way, emphasizing on advantages but never on drawbacks.
This section of Sousvidecooking.org blog is dedicated to reviews and tests of the most popular equipment used by professionals and sous vide enthusiasts in general.
For each piece of sous vide equipment I made a review (I). Each product is also compared in different pages with all the other products of the market (II). A summary of all products is also available (III). Comparison between two products is not an easy thing. Therefore, I have selected objective criteria that will be the same for all tests:
- Size: if you are an individual the place taken by your sous vide equipment is an issue, especially if you have a small kitchen. Will your sous vide appliance enter in one of your kitchen drawers?
- Weight: can you manage with a 5 Kg machine? If you are a professional, and you need carrying immersion circulators for demos, weight is important for you.
- Power: the more powerful your appliance is the faster it will heat the water contained in your water bath.
- Max. tank/vessel capacity: if you are a professional and doing catering, 50 litres capacity could be important for you. If you are an individual, 20 litres capacity is totally sufficient.
- Safety: cooking sous vide can take very long, from some minutes (fish) to days (special cuts of meat). Even at 50°C water evaporates. For food safety reasons a pouch must always be immersed in water. This is a reason why a float switch system is the best way to warn cooks about a low water level in a water bath.
- Stability: cooking sous vide is precise, 1.5°C temperature variation can lead to different results.
- Maintenance, cleaning of the sous vide equipment : key point if you are an intensive user or a professional.
I hope these pages will help you to choose the best equipment according to your needs.
I.1. Immersion Circulator
I.2. Non stirred water bath
- Sousvidesupreme (coming soon)
I.3. PID Controller
- Freshmealssolution : Sousvidemagic (coming soon)
II. Sous vide equipment comparison (detailled)
- Addelice swid Vs Julabo Pearl
- Vac-star SV Chef Vs Polyscience SV Professional
- Addelice swid Vs Polyscience Sous Vide Professional (coming soon)
- Addelice Swid Vs Sousvidesupreme (coming soon)
- Addelice Swid Vs Sousvidemagic (coming soon)
- Julabo Pearl Vs Polyscience Sous vide Professional (coming soon)
- Julabo Pearl Vs Sousvidesupreme (coming soon)
- Julabo Pearl Vs Sousvidemagic (coming soon)
- Polyscience Sous Vide Professional Vs Sousvidesupreme (coming soon)
- Polyscience Sous Vide Professional Vs Sousvidemagic (coming soon)
- Sousvidemagic Vs Sousvidesupreme (coming soon)
III. Sous vide equipment comparison (summary) : clic on the image below to download the Pdf doc
Coming soon a review of the most representative sous vide equipment of the market (from the left to the right) on this page :
- SousVide Professional of Polyscience (Immersion Circulator)
- Sous Vide Chef of Vac-Star (Immersion Cirdulator) Swid by Addélice (Immersion Circulator)
- Pearl by Julabo (Immersion Circulator)
- SousVideMagic by FreshMealsSolutions + Bubbler (PID Controler SVM-FMM1500D)
- SousVide Supreme (Unstired PID controlled water bath)
- Sous Vide Chef of Vac-Star (Immersion Circulator)
Polyscience launched on Youtube a video about their new Immersion Circulator, the MX version.
The design of this equipment is fantastic but will this immersion circulator be affordable for sous vide chefs and individuals? Except this video, no information is available on the net. If you have some, feel free to tell us!
Here is the Youtube video!
Today Polyscience made the demonstration that a non stired water bath cannot be as efficient as an immersion circulator. It is funny to see that Polyscience directly mentions Sousvidesupreme in the TAG of the article.
Polyscience video indicates clearely that a non stired water bath has a longer response time to reach the desired core temperature. Therefore, it is obvious that Douglas Baldwin cooking tables sould be used with care. Douglas Baldwin indicates in the Pratical Guide to Sous Vide “With all these digital controllers, I highly recommend setting the temperature offset (measured near the temperature at which you wish to cook) using a high quality digital thermometer. Indeed, at the default settings the thermistors used in the above controllers can easily be off 2–4°F (1–2°C)”.
Freshmealsolutions mentions clearely in the user manual of the SousVideMagic : “If you don’t have a proper food core temperature sensor probe, always cook at desired core temperature settings for the duration as specified by reliable recipes with an additional safety factor of at least 25% longer…”
In addition the manual indicates “The default settings are designed to overshoot 1 or 2 degree higher for safety reasons. You can reduce the overshoot by making your own PID adjustments. See the document “PID Tuning”.”