Progurt Maker Selection

Edition: 2022-08-15

I want to make one or more of the program probiotic yogurts [progurts], what device should I buy?
is an FAQ.

The Blog SHOP link doesn’t presently have any device suggestions (and when it does, the brand shortly thereafter may jack up the price, or inexplicably discontinue the device). This FAQ article isn’t going to make any specific product recommendations either.

As this is a self-directed healthcare site, for this topic, here is a general process for self-directed shopping. Don’t just run out and buy a pot that promises a “yogurt” cycle, or, like me, you’re likely to end up with a not-so-smart-pot sitting idle in the basement because it couldn’t do the job.

Pre-selection Pre-requisites

1. What else might you need the device for?
   Typical yogurt & progurt temperatures may not be useful for other kinds of cooking. If you can find a smart pot that meets progurt requirements, it might have many other uses. Sous vide devices are also broadly more useful.
    
2. How reliable is your AC power?
   Is there is a non-trivial risk of a power glitch over a 36-hour ferment? There is at my rural location. Outages up to a half hour or so are not a problem per se, but what the device does when power is restored must be understood. Slow cookers can often resume on power interruptions. Not-so-smart pots often don’t.
   
   Putting the device on a UPS (uninterruptible power supply) is an option, but is apt to be costly, due to the basic power requirements of heating devices, often in the kW range. More than a few minutes of UPS run-time would be very expensive.
    
3. Do you have digital probe thermometer?
   You probably already have this covered. One of these inexpensive devices is important to verify target cooker temperature and temperature regulation.
    
4. How much progurt do you need to make at once?
   This is unlikely to be an issue, but needs checked off. As a practical matter, whatever device you obtain can only make a batch once every two days. For a small family, a quart or two at a time keeps up. For a larger number of consumers, a device that does a half gallon (2L) or more might be needed.
    
5. Do you need the device to "cold start"?
   Cold-start means providing ample heat to get from refrigerator temperature to ferment temperature in less than an hour or so. Cold-start isn’t a recipe requirement, but you’ll need a work-flow modification for warm-start.
    
6. Container Considerations
   Container depth doesn’t really matter very much. In my experience, the fermentation works at any volume and in any depth up to about 8in/20cm. Multiple containers does {usually} mean that you need to pre-mix the brew in some other container, then transfer it to the fermentation vessels.

The Product Hunt

Assuming that progurt, and perhaps traditional yogurt are the only requirements, the basic choices are self-heated containers and immersion heaters (such as stick sous vide). For any device that looks interesting:

0. Download the user manual.
   No download? No sale.
   A lot of yogurt makers fail this basic 21st Century merchandising competency test.

Then check for:

1. Just what are the “yogurt” pre-sets (if any)?
   If the device has such preset(s), at what exact temperature(s)? Many devices fail to document this, which may also be a blanket disqualifier.
    
2. Does the device have any modes with suitable [recipe] temperatures?
   Can the device be set to an arbitrary temp between
   90° and 125°F, ±2°F (32-52°C ±1°C),
   in order to cover all current and near-term recipes. This may require using a custom mode that is different from any “yogurt” presets.
    
3. What is the maximum run-time for recipe temperatures?
   For the custom mode (and any yogurt presets that seem useful), can the device be set to run for at least 12 hours in that mode, so that you can get some sleep, and/or go out for the day between re-programming sessions. Longer run times, or indefinite, are of course ideal.
    
4. What is the power-resume behavior?
   Most devices with electronic controls power-up in their power-on state, which is heater-off. Oops. The exact behavior is not likely to be addressed in the user manual, so you may have to search reseller feedback comments, device review sites or brand support forums to find out. Naturally, you may learn other illuminating things about the device on those venues.
    
5. Regulatory and safety due diligence.
   Considering Dr. Davis’ near-incendiary experience with a Gourmia (blog, PCM), check product web pages and user manual for regulatory and safety declarations. A surprising fraction of products drop-shipped from Asia either lack certifications required in your locale, or bear counterfeit icons. Don’t count on your national Customs officials to protect you.

Important: Batch Zero

Save the box, in case you have to return the device.

With the device in hand:

1. Recipe: water only
   Run a test using a batch-equivalent amount of just water, perhaps pre-chilled in the fridge for extra insight.
    
2. Probe and Program
   Insert your probe thermometer. Run an expected progurt mode.
    
3. Timelines
   See how long it takes to go from cold to target temp. Try the probe at different locations in the container, looking for hot spots. Let the test run for at least 12 hours, to verify that it can.

Do you need a yogurt maker at all?

Solutions can be ad-hoc. I use an old cheese warming tray in a cooler (heating the air, not the fermentation vessel), controlled by an apiary thermostat. It can’t warm-start, but is otherwise very simple to run (and resumes-as-set after power glitches).

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Bob Niland [disclosures] [topics] [abbreviations]