Float for a wireless thermometer

I have a set of ThermoMaven wireless thermometers. I can't believe how good this product is - how can something so small be put into an oven at high temperature and transmit the internal temperature of the food being cooked in real time?

Anyway, these thermometers work and work really well. The temperature probes are waterproof (they can be cleaned in a dishwasher) but unfortunately, they don't float, so I can't use them for measuring temperatures of liquids during homebrewing. The float design shown here will hold one of these probes in the correct position while floating on a heated liquid. I use this to monitor mash temperature, the boil, cooling. The battery lasts a few hours which prevents it from monitoring fermentations.

An STL file is provided that fits the ThermoMaven temperature probes. A Fusion 360 CAD file is also provided to enable users to customize this design for other probes.

The use of this device is described in an article entitled "" in the July/August 2025 issue