Freeze dried oak tannins: where our trials stand
A research track, not a finished product. Here is what we are looking for, what we already measure, and what still resists us.
We have worked oak in solid form for five generations, and in tannin form for much less time. Freeze drying, meaning drying an extract with cold and vacuum rather than with heat, comes up regularly in our workshop discussions and in the ones we have with EBX about tannins. The idea can be stated in one sentence: remove the water from an oak extract without heating it, to see whether the most volatile fraction comes through better preserved. Stating the idea is the easy part.
Why this track interests us
When you extract oak in the liquid phase and then dry the extract, drying is the moment when you lose the most. The light molecules, the ones that carry a good share of what the taster calls fruity and floral, leave with the vapor. Drying cold should, in theory, keep more of them. And we do mean in theory: between the behavior of an extract in a laboratory chamber and its behavior in a batch of several hundred kilos, there is a gap we have not finished measuring.
This track extends older work of ours, on low temperature extraction. It does not replace it and it makes nothing obsolete. It is a process variant we are testing, alongside what we already produce.
What we know how to dose today
Research and catalog need to be kept apart. The tannins we deliver today exist in liquid form and in powder form, and the equivalence between the two is established and verified at our place.
| Form | Concentration | Equivalence |
|---|---|---|
| Liquid tannin | 20 % | 1 L is equivalent to 200 g of powder |
| Powder tannin | dry product | 200 g is equivalent to 1 L of liquid |
That conversion is the basis of all our dosage calculations, along with the other g/hL equivalences built into our oak dosage simulator. A freeze dried extract, if it ever comes through, will have to fit into that same framework and convert just as simply, otherwise it will be of no use to anyone in the cellar.
What we do not know yet
The list is longer than the list of our certainties, and we would rather give it as it is.
- Actual solubility in the tank. A powder that disperses well in a beaker at 20 °C (68 °F) does not necessarily behave the same way in a cold wine at the end of winter.
- Stability over time. A dry extract is sensitive to ambient humidity, and we do not yet have enough hindsight on batches stored for several seasons.
- The share of the effect that comes from the process itself, and the share that simply comes from the starting oak, air dried for 36 months. Separating the two calls for long series.
- The energy cost. A process that does not hold up economically stays a laboratory curiosity.
So we are announcing no date, no product reference and no figures on performance. When we have series that hold up across several vintages, we will publish them, including if they do not go the way we hoped.
In the meantime, how we adjust a tannin
For the tannins we produce today, the only honest way to set a dose is still the trial on your own wine. A drop by drop addition on a small volume, tasted by several people, will teach you more than any average from us. That is what our drop by drop tannin trial is for.
Our ranges then serve to refine the character: Couleurs Primaires when you want to build a character yourself by reference, La Recette when you prefer a profile that is already put together. Here too the tool does not decide, it suggests. If a figure looks wrong to you in your cellar, write to us. We would rather correct it than defend it.
Read next : La Recette: when the profile shapes the result · Le Nuancier des Possibles : les "Couleurs Primaires"