An interview with Christoph Hoch about mousiness in wine
Please introduce yourself!
Christoph Hoch, family winegrower in Hollenburg a.d. Donau/ Austria
What are your experiences with mousiness in biodynamic wine and what has this taught you about mousiness?
Mousiness was not a topic for us before 2018 – we didn’t hear about it before and we never had any known example – that is simply not on our radar. At some point in early 2019 we received a wine back for the first time with “mousiness” as a comment – more out of curiosity, we invited some colleagues and friends and tried to name it. It was immediately clear for us that there was not much wrong with the wine, but it needs to be understood and from now on in focus.
We analyzed our wines, our yeasts and what not – we found similarities in all the wines. We have a smell and taste that is almost identical to the same behavior of our animals – a lovely pet hamster we all know – mousy! How is that, it is really good question!
I only can answer it from our CURRENT POINT of knowledge (by 2024) – collected by all the experiences it is a by-product of strain of Lactic-bacillus borne from malolactic bacteria strain.
“Mousiness was not a topic for us before 2018 – we didn’t hear about it before and we never had any known example – that is simply not on our radar. ”
When did you first experience mousiness?
Clearly 2018
How does it smell like?
I would describe it like a slight nutty cheese rind smell that just lingers for a very long time – if you smell it you are never sure whether you are right or wrong, but with the time it’s just there.
What have you learned about mousy wines from this?
The knowledge gathered between 2018 and now is more or less the journey from my grandfather (current) knowledge until today. I think that it happens in the very beginning of vinification, sooner than we think, because it is also a problem of inoculation and fresh malolactic fermentation. So, we need to dedicate special focus to biodiversity, the yeast strains we are working with and also controlling, fermenting temperatures and overripe grapes. I’d say because the vintage is extremely important, mousy wines appear mostly in warmer years, when the grapes and everything else already comes to its limit and if the natural ph is around 3,5 or 15-18°C you know it’s going to happen. Above 15°C, it is getting dangerous.
How does it happen?
Again, from our knowledge right now:
We think that it happens in the very beginning of vinification, shortly after malolactic inoculation, in some wines, yeast strain, condition and temperature are key. Additionally, it is some organic wine we have been fermenting by our friends, also using cultivated yeast, seem to have it less. In our area, this isn’t as usual, so mousy fermentation is almost unavoidable. Of course, if the winery can stay above lactic bacteria and therefore also regular changes to our natural lactic, it can be said that in this year’s mousy wine problem became unpredictable and problematic in winemaking.
How do you avoid mousiness?
Well, again – so far, I can only tell by feedback from wineries and brewers, since I haven’t personally dealt with it myself so far.
Since we know temperature is an issue, harvesting early in the morning and stopping right before getting too warm/hot could be crucial.
What when it is also warm in the nights (because the harvest is so early)? Then the chilling is fast and quickly after pressing is important!
Add a (spontaneous) fermenting grape juice already to grapes, so that the right culture is working right away on the grapes.
Add some wine from last vintage – this is also only a guess – it works in our area: Lactic bacteria!
Besides the spontaneous start: all yeasts of course have a (big) problem under cultivation: so if we consider inoculation/fining agent, it can be said that all wineries should control carefully to avoid mousy. If it is already too late, then do all winemaking education possible – to avoid getting mousiness.
How to treat mousy wine?
Colder harvesting temperatures – around 15°C, or lower
Lower pH value (higher acidity!)
If you get mousiness, will it stay in the tank or in the wine/disappear with time or by accident?
It can and will disappear with time!
In a tank, I have very bad experience – it might stay here, the wooden barrel it is faster, but still depending on intensity. In bottles it can be months to 2 years. We have now simple saying: "you catch" once the mouse is here. Too much and fast oxygen will also not make it intense. Sulphur at mousiness will keep it – ONLY tested when sulphur added before the young wine has year(s), but it is not repairable moussiness BEFORE it appears, you need to watch the grape maturity as early as you can!
Can we/consumers do anything about the mousiness?
Oh yeah… Unfortunately not enough of it, mousse is (so far) not wine for everyone, I only see like for winemaker suffering and table moussiness a high preference. So, we taste with colleagues, mousse should be clearly communicated to consumers that it is almost no official known.
How to avoid mousse wine
House mouse: The wine is at opening not strong, but will get quickly mousy. I hope that if you want mousse, look for wine with a house mousy. After the first pour it will get stronger. You will recognize how everyone to drink it once hour.
Rope mouse: You don’t recognize the mousse in the beginning, only when you swallow the wine, you will have a mousy ending up the throat with a mix. Drinkable for some, in combination with food – combined with more spicy or heavy food, so that you don’t have the mousse fully return to the mouth.
Ratz: Super flat mousse. No chance for anyone. In any way, to keep a bottle which is mousy for a long time will disappoint the drinker and it might take very long time and consumers to let be loosed, for relaxation – no it doesn’t get flat as an option.
Will a wine be “still a mouse” or can it be in a small amount?
See party above, there are small parties and mouses. Mousiness now seems to be a known part of nice wine or (we think) elegant and specific, not fully ripe, and sometimes, showing slight hints of mousiness.
In others wines it depends how much mousse we accept and drink fast.
