(checked 2026-10-10)14,516 ratings; the same rating count appears on the green color listing (B0C2YP5NJQ), so colors are pooled.
Amazon's best-selling warmer in our search (10K+ bought in the past month), packed with modes. Experts were unimpressed: Wirecutter's unit malfunctioned mid-cycle, and BabyGearLab's 'Grownsy Classic' was slow on the maker's settings yet far too hot on its highest ones.
Top complaints
- Slow on recommended settings, too hot on high
BabyGearLab's Grownsy Classic never reached 98°F within 12 minutes on the manual's settings (about 95°F average), but on the hottest settings milk was over 138°F at auto-shutoff, which it calls dangerously hot. (BabyGearLab doesn't say whether its unit is the 8-in-1 OG.)
- Warming results are mixed
Amazon's review summary says heating performance, temperature control and heating time get mixed feedback, with some owners reporting it doesn't warm well or is inconsistent.
- Malfunction in testing
Wirecutter eliminated the Grownsy 8-in-1 Fast Milk Warmer early because it began malfunctioning in the middle of a heating cycle.
Source: Wirecutter (NYT)
What owners love
- Easy and quick, owners say
Amazon's summary says customers find it easy to use, quick to heat and good value, and like the sanitizing feature.
- Very consistent at BabyGearLab
Its Grownsy Classic stayed within 93-98°F at 12 minutes, a narrow range for the group, and stayed under 104°F on recommended settings.
- Many functions
Grownsy lists fast warming, thaw, keep-warm, steaming, food heating, a timer, adjustable temperature and an anti-scald basket.
Source: Amazon.com product page
- You want expert-tested reliability
- You don't want to read a warming chart
- You want easy descaling
- Lots of modes (thaw, keep-warm, food, steam)
- A built-in timer
- Mid-range budgets
Scores (tap for why)
What experts say
- BabyGearLab: Grownsy Classic ranked 4 of 11 (67): very consistent, but not warm enough on recommended settings, overheats on high settings, and is harder to use and clean; the reviewers wouldn't recommend it to friends.
- Wirecutter (NYT): Eliminated the Grownsy 8-in-1 Fast Milk Warmer early after it malfunctioned mid-cycle.