Sadly, it turns out that silicone trays, despite their other charms, truly do soak up freezer smells and flavors over time and there isn't much to be done about it. Thus we no longer recommend them.
However, the good news is that once again the baby food freezing supplies industry has come to our rescue. This time it's via a brand we love, Oxo, and their amusingly appropriately named "Tot" line. Oh, they think it's about children, but we know it's really about Royal Navy rum rations.
On the recommendation of Tipple Tuesday founder Lance Arthur, we've switched over to using the Oxo Tot "Baby Blocks" 4 ounce and 2 ounce sizes of their individual freezing containers.
The containers are securely lidded—with a no-spill top, allowing these to be transported safely for bartending in locations without freezer access—and if allowed to sit for just a few moments after being removed from the freezer, the ice can be easily popped free. No more wrestling with stubborn silicone trays!
When filling, note the interior fill line which provides room for the ice to expand as it freezes without popping the top open. Because these are separate units, you can refill each one immediately upon use rather than waiting to empty a whole tray and thus you can maintain a more constant supply of good ice. Simply rotate the base to position the least-frozen containers to the back and grab the oldest ice from the front when you next need some.
We use the larger cube (4 ounce) in our mixing glass, and the smaller ones in the glass for drinks on the rocks.