Rrawhide,
Like oak barrels, the amount of oak flavoring and tannin that is extracted from the cubes is high in the beginning and tapers off over time. This is the same with used barrels vs. new barrels. A new barrel extraction rate is high and a used barrel tapers off.
I remember early on in my winemaking experience finding information from a wine cube manufacturer (I can't seem to locate the proof now) that cubes could be reused if they were rinsed and then lightly sanitized, being sure to keep the cubes moist which means transferring them right from one wine to another and not letting them sit out.Letting them sit out can inspire mold orother microorganism growth. I seem to recall this resource also noted that it perhaps would be better to use the oak cubes in a primary fermentation for their secondary use, although I can't confirm.
Given all of that information, do I personally resuse cubes - no. Instead, I bettereconomize oak cube usageby half-dosing batches and letting them sit for twice as long (rough estimate in timethat needs to be adjusted by your taste tests). In this fashion, you won't burn through your fresh cubes as quickly and will stretch the oak, so to speak.
- Jim