Monday, February 24, 2014

Comparison Of Two Kickstarter-funded Sous Vide Devices

Sous Vide

Sous vide cooking requires heating a tub of water to a precise temperature and holding it there over a long period of time (often several hours), putting food in plastic bags, evacuating the air from the bags (typically), and dropping the bags in the water for the desired period of time. Often this is followed by removing the food from the bags and normal-cooking it for a brief period (for example, to add a nice charred/seared finish).

There are two basic approaches for keeping temperature constant:
  1. A water bath with heating elements underneath (and sometimes also on the sides) that relies on convection to produce an even temperature throughout. One vendor of these calls them "water ovens".
  2. An immersion circulator that provides heat, plus actively circulates the water to ensure even temperature.
Both approaches use accurate thermometers and control devices (typically PIDs) to avoid thermal undershoot and overshoot. Both approaches have safety features such as low-level sensors, etc.

Advocates for immersion circulators have demonstrated unwanted temperature gradients in water ovens, by dropping a lot of frozen food in the water at once. Water-oven advocates claim this was an unfair test, at least for home use, because the quantity of frozen food was unrealistic. They may or may not have a point.

The one undeniable drawback to the water-oven approach is the size of the machine. In a restaurant, this is perhaps not a concern, but in a house it actually matters. The leading model of water ovens is as big as a bread maker, and for casual home use could be a boat anchor if it's not used all the time (which is true come to think of it of bread makers too). In contrast, an immersion circulator can be clipped into any large pot the home cook already owns, and can be stored in a small volume when not in use.

So, we wanted to buy an immersion circulator instead of a water oven.

Early sous vide experimenters repurposed expensive lab equipment, and at least one lab-equipment vendor (PolyScience) was smart enough to realize they had a new sales channel, and start making purpose-built immersion circulators.

But they were still expensive.

Note: PolyScience sells lower-priced immersion circulators: But we didn't know about them at the time, or perhaps they were recently introduced. We only knew about immersion circulators costing $700 or more.


While we were looking for an affordable model, Nomiku did a Kickstarter for a lower-cost (but still high-quality) immersion circulator:

We invested in one.

Then Sansaire did a Kickstarter for another immersion circulator:

We invested in one of those as well, in case the Nomiku failed to deliver, or wasn't any good.

(Note that both projects were funded quickly and greatly exceeded their funding goals. There was obviously pent-up demand for such a product.)


Having now received both units and tried them out, here is our evaluation:

  • Smaller (width and height)
  • Quieter
  • More expensive
  • Cover is recommended to keep heat in, and pre-notched cover is not available from vendor
  • Slower to reach desired temperature
  • Smaller range of water levels
  • Harder to clean inside
  • Bigger (width and height)
  • Louder (but still not very loud)
  • Less expensive
  • No cover needed
  • Reaches desired temperature quickly
  • Larger range of water levels
  • Easier to clean inside
  • Some burrs on mounting clip (they're working on improving this)
  • Well-designed
  • Well-manufactured
  • Well-documented
  • Well-packaged
  • Excellent customer support
  • Prompt shipping
  • Hold constant temperature correctly with little or no variance once equilibrium is reached
We haven't used either unit long enough to comment on long-term reliability. At some point I'll post an update.


If space is at a premium and/or if you plan to only cook small amounts, get the Nomiku. Otherwise, get the Sansaire.


Despite showing metal pots on their websites, both vendors recommend using Cambro polycarbonate tubs (12 quart for Nomiku:, 4.75 gallon for Sansaire: The tub recommended for the Sansaire has ridges on the underside that provide some insulation from cold countertops.

Although not required for the Sansaire, a cover will reduce evaporation, and holds in heat (which reduces energy cost, but does not affect the ability of the Sansaire to keep constant temperature). No pre-notched cover is available for the Sansaire (same as for the Nomiku), and cutting one would be problematic for a Sansaire because the hole would need to be some distance from the edge, producing a long void that would leak heat. If you want a cover with the Sansaire, you can use floating plastic balls, which are available from (case of 1000, 20mm, polypropylene floating spheres: These are also sold by PolyScience, in smaller quantity, for a lot more money.

(PolyScience sells tubs and pre-cut covers, in various sizes, for their immersion circulators. It would be helpful if Nomiku did the same.)


Side-by-side comparison of Sansaire and Nomiku, in recommended tubs:

Nomiku cover, courtesy of my brother. Hole was cut with 2+1/4" hole saw in a drill. Notch connecting edge to hole was cut with fine-toothed hacksaw. Edges were lightly sanded, but googling around for advice on how to cut polycarbonate, some posts recommend lightly running a butane torch flame over the cuts, which will (they claim) melt them gently into a smooth finish.

If you screw up, you can get another top from Amazon for about $9.

Similar review on another site:

Inexpensive DIY Wine-preservation System

Wine goes bad pretty quickly when exposed to air, which wouldn't be a problem if every opened bottle was finished right away, but sometimes a bottle is only partially consumed.

To address this, there are many solutions available: google for wine preservation system.

The various solutions fall into one of these categories:
  1. Replace the bottle with a bag that can be squeezed so the wine comes up to the top, leaving no air to react.
  2. Displace the wine up to the top of the bottle by pouring clean inert beads into the bottle.
  3. Pour the wine into a smaller bottle, and have a set of bottles of various sizes.
  4. Remove the air from the bottle (by creating a partial vacuum in the bottle).
  5. Replace the air in the bottle with an inert gas.
  1. Bags work but turn an aesthetically pleasing bottle of wine into an ugly plastic sack. And the sack is difficult to clean and dry. Plus I don't really like the idea of wine sitting in contact with plastic for days.
  2. Beads work but are hard to clean and then dry (a colander is good for cleaning, but drying is a pain, because water sticks in the voids between the beads).
  3. Smaller bottles don't work as well as beads, because the step sizes between bottles are larger than the volume of one bead. And the bottles are hard to clean and dry.
  4. Creating a partial vacuum can diminish/change the flavor of the wine, probably because it draws off useful volatiles (for example, dissolved CO2).
  5. Using an inert gas works very well. The step size is the size of a molecule, and when the bottle is opened the gas disperses and there is nothing to clean or dry.
You can buy an inert-gas system. They cost a lot of money, and typically even if the base unit isn't outright expensive, the replacement gas canisters are expensive (including, oddly, Hazmat fees for shipping the bottles, even though the gas is harmless). They wouldn't need to be expensive, but, like giving away the handle and charging for the blades, that's how the inert-gas-wine-preservation-system vendors make their money.

You can instead create an inexpensive inert-gas solution entirely from off-the-shelf parts. You don't need to buy anything fancy.
  1. Call your local industrial-gas supply shop. For example, Airgas. They are pretty much everywhere, because welders, food systems, labs, etc. need various gases.
  2. Ask for their smallest tank of argon. I asked for food-grade argon, and they didn't have it in the smallest bottle size. But when I asked what the "contaminants" are in regular argon, they said it was just air, and the percentage is very low. They also said that's what wineries use (they don't need food-grade). Don't worry about it.
  3. While at the gas supplier, also get a regulator. Show them the photo below so they know what kind of regulator you need. Ask them to install and test it. Ask them to show you how to use it (hint: you need to turn the big valve on top of the tank first, then the little valve on the top left of the assembly in the photo).
  4. Pay for the regulator, the tank rental, and the argon.
  5. Take the tank/regulator assembly and an empty wine bottle to a local hardware store with a good selection of small pipes and adapters, and ask them to make something that looks like the photo.

The idea is for the narrow end to fit into the neck of the wine bottle, with room around the nozzle for air to escape as you fill the bottle. You might consider adding a small hose to the end of the fitting, to poke down into the bottle.

When filling a bottle with argon, open the small valve the least possible amount, to inject argon into the bottle as gently as possible.

When you feel you've replaced the air with argon as much as possible, quickly remove the nozzle, shut off the small valve (firmly, but don't overtighten), put the cork (or some other stopper) in the bottle, and then shut off the big value (again firmly, but don't overtighten).

Even the smallest bottle of argon lasts for ages--not much gas is used per wine bottle. We're still on our initial purchase of argon.

When you finally run out of argon, take the bottle/regulator assembly back to the supplier, and get a replacement bottle. (They just swap bottles, don't refill the one you have). Ask them to install and test the regulator on the new bottle.

Note: It's a good idea to attach a chain, wire, rope, strap, etc. to a wall and around some part of the argon tank (so it doesn't tip over and snap off the top, which is a rare occurrence but quite spectacular when it happens).

Caveat: Wineries have big tanks and special piping/techniques for sparging (filling the headspace with inert gas, When you manually squirt some gas into a wine bottle, even taking care not to create turbulence, you can't achieve the gentle laminar flow wineries achieve, so you probably aren't displacing all of the air so much as diluting the air. But that's still better than nothing, and in practice this has worked well for me.