Cool! I’ve had a handful of Radikon wines and even have one in my cellar ATM, but never had the guts to experiment how they survive over the course of several days. They are always so wild I’m afraid they will go haywire if left open for too long, as no-SO2 wines often do. However, the best don’t turn bad and apparently Radikon is in that tier.
and now presents as good of a time as any to ask, "What does “mousy” mean in the context of wine? I’ve seen that used many times, but don’t know what it means.
The short answer is: it’s a sort of very unpleasant flavor of stale bread, rancid nuts, Weetabix and/or sesame seeds that normally appears in the aftertaste. The wine’s nose is often clean (however tends to be accompanied by elevated levels of VA and/or brett) and the taste as well. However quite soon (or even immediately) after you swallow/spit the wine, this nutty/bready/dirty flavor appears, often eliminating any other flavors there were. A great wine can turn horrid in matter of just seconds. I’ve had wines I thought I loved and then suddenly the aftertaste is so bad you want to retch. The term “mousy” comes from the taste being very similar to mouse droppings / uncleaned pet rodent cage (as attested in person by multiple pet rat owners).
The long answer is: it’s (often, not always) THP aka. tetrahydropyridine, a chemical compound that is produced by unwanted lactic bacteria, or to lesser extent, brettanomyces (I’ve had lots of mousy beers and wines that have not had any obvious bretty qualities, meaning that brett is not the main culprit, unlike many seem to think). This compound is non-volatile in low-pH (ie. acidic) medium, which means you really can’t smell (and taste) it. However, when you swallow the wine/beer, your saliva neutralises the last remaining drops, raising its pH up to 7, when the compound becomes volatile and suddenly you are able to “taste” it as the compound vapors move retronasally from your mouth and throat to your nasal cavity, where the compounds are registered and “tasted”, making the aftertaste feel, well, mousy (or “hantavirus” as one mr. Hill here on the forum describes it - which I find rather odd, because viruses don’t smell or taste of anything).
In very high concentrations THP actually becomes detectable already in the nose. 95% of the mousy wines and beers I’ve had have been only rather mildly mousy in the aftertaste, making them unpleasant and faulty, but nothing too bad. However, I’ve had a few handful of beverages where the mousiness has been very obvious already in the nose. It doesn’t smell as bad as the taste, but still bad. You can already say there that “this is gonna be helluva mousy” - and you’re never wrong. These are rare, but they still prove that while mainly a fault tasted only in aftertaste, it is not exclusively in the aftertaste.
The compound is created in the presence of oxygen and in the absence of SO2. Normally even a smallest amount of SO2 is enough to knock out the rogue lactic bacteria and keep brett from producing any THP, which is why it is mainly a problem of the no-SO2 wines. Its effect also seems to be exacerbated by the presence of oxygen; a wine that feels wild and funky upon opening, might be completely devoid of mousiness immediately after the cork is popped, but starting to exhibit mousy flavors after an hour or two, turning completely undrinkable by the next day.