Most reputable medical organizations recommend that babies should be breastfed by their mothers for the first six months of their life. But there are some people out there who, thanks to a quirk of biology, simply can't do it, and have to resort to formula milk. In 2007, the World Health Organization guidelines on how infant feed was prepared, changed. Instead of mass-producing bottles, you now had to make each meal fresh on-demand.

But making up a bottle can take up to an hour, so in 2013, Tommee Tippee launched the Perfect Prep, a Keurig-style device for almost-instant formula preparation. Push the device's one large button and it'll spray a "hot shot" of 70 degree celsius (158f) water into the bottom of a bottle. Add the requisite quantity of powdered baby formula and, once you've shaken to mix, push the button again. The bottle is then filled with filtered cold water, bringing the temperature down to one that an infant can drink straight away. 70 degrees, FYI, is the temperature warm enough to kill two harmful bacteria: Cronobacter sakazakii (Enterobacter) and Salmonella.

So, one weekday afternoon, I handed £65 ($95) to Amazon, where it was on sale, and set about trying to determine what exactly was so bad about it. The first issue is that with traditional formula preparation, you're using boiled water that's then left to cool for 30 minutes. The Perfect Prep, meanwhile, uses a filter that, the company claims, has holes too small for water-borne bacteria to pass through. I can't prove its efficacy, but I also can't say with any certainty that it's unsafe, and the science behind the idea is sound, at least.

The other issue centers around the "hot shot," although the only semi-official criticism I have found comes from the First Steps Nutrition Trust. In 2015, it published a paper that quoted unpublished university research, saying that the hot shot didn't stay warm enough for long enough. So, the first scoop of powdered formula may hit the water when it was 70 degrees, and therefore hot enough to kill any bacteria inside. But the third, fourth and fifth may be added when the water dropped below that temperature, and that's dangerous.

Thankfully, you don't need to be an expert to determine the efficacy of this, and so armed with a stopwatch and temperature probe, I tested it. The "hot shot" actually came out of my machine at 77 degrees celsius (170.6f) , a little warmer than the company promises in its material. It took an average of 50 seconds before the temperature hit 70 dead, but after that, we'd hit the red zone. Naturally, water will cool at different rates depending on the ambient temperature, but I was satisfied that there is a safe margin.

It's easy to infer that the two minute timer is a safety feature.

The manual for the Perfect Prep says that you have two minutes to add the powdered formula to the bottle before it'll beep to say that you're too late. But by two minutes, the temperature had dropped to just 63 degrees (145.4f), far too low to kill enough bacteria. It's an issue that I raised with the company's representatives, who clarified that the two minute timer isn't a safety feature. Instead, it's the amount of time that elapses before the device resets itself, which isn't made particularly clear in the documentation. It's something that, I sincerely hope, the company will look to alter in future versions of the manual.

One of the reasons that it's so hard to speak with any certainty about this device is because the debate has been hijacked. Advocacy groups with an anti-formula milk stance like Baby Milk Action reported on the device, calling it the "Perfect Violation." Individual NHS staffers will speak out against it off the record, but the service itself has no official position on its use. I even contacted the National Centre for Clinical Excellence, which said that it has never been asked to study the safety of the hardware.

But once my daughter was six weeks old, and therefore stronger, we decided to try using the device to produce her feeds. We'd satisfied ourselves to the best of our ability that, if we were smart, and added the formula in one go, it would hit the water while it remained over 70 degrees. We added pre-filtered water to the reservoir to reduce any burden on the built-in filter, keep a constant watch for any visible bacterial growth on the device and monitor our daughter's stools for any feed-based issues. I can't be certain that this device is killing all potential bacteria, but we weighed up the pros and cons of what could happen and I think that there's an acceptable level of risk.

Our days now are no longer spent simply hovering over kettles with stopwatches while we try to comfort a mewling baby. The hours that were devoted to milk preparation has been reallocated to spending with our little girl and watching her grow. Night time feeding was the bane of our lives, but now we can just hit a button as soon as she stirs and have milk ready for when she wakes. It's also enabled us to discard feeds after 45 minutes, rather than eking out each precious bottle for as long as possible. She gets fresher, warmer bottles and we get a third of our day back, it seems like a fair deal.

But just because I'm a convert, doesn't mean that I'm going to recommend everyone get one sight unseen. Gadgets like this are potentially dangerous in the wrong hands because they may not understand the science that underpins it. A few days of trawling through parenting forums showed me how little understanding some people have about basic biology. One horrifying thread even suggested that it was safe to make infant formula with water from the hot tap rather than a kettle*. If you're smart then I see no reason to be scared of this device, but if you're not... well, there's a reason that packets of Silica Gel have "do not eat" written on them.

* Don't do this.