It was raining when I wrote this. Forgive me if it goes astray…
This year, I will be making my first white wine: a Fiano. I have some Fiano vines in large pots, but before I put them in the vineyard (and spend the money on the posts, labor, irrigation and water, etc), I want to see if I can successfully make a white wine with my resources.
There are some very essential questions I have to answer about the first part of primary fermentation: if I use a low foaming yeast, should I expect the wine to surge up the air lock? Should run the fermentation in one vessel filled to the top, or two vessels with some head space and then consolidate as the ferment slows down?
Anyone reading this, and who knows the answer to that question, is welcome to comment or contact me.
Now, the second part of the primary fermentation will be decisive in determining the structure of my finished wine. I opened a bottle of the most recent vintage of the Fiano I want to replicate and did some testing. I had the following results:
- 2-drop method (2X volumes – 20 dr H20, 4 dr wine): about 2.5%
- 5-drop method (done twice: 1X and 2X volumes): 1% to 1.5%
- Very Highly Positive: >500mg/L
My main goals in this part of the primary fermentation are to: 1) preserve RS at about 2%, and 2) prevent malolactic fermentation.
There are several ways to arrest primary fermentation: 1) high-dose SO2, 2) chilling the wine to about 30°F for about six to eight weeks, 3) Pasteurization or flash Pasteurization, and 4) sterile filtering the wine. Re-fermentation can be prevented by both filtration and addition of sorbate to the wine at bottling.
Malolactic fermentation can be prevented by the addition of lysozyme (trade name: LysoVin). It is an egg extract which inhibits lactic species. Because it is an egg extract, it may be allergenic, as has been recently reported. But I am not concerned enough about this to exclude the use of lysozyme from my regimen.
Sterile filtering requires a financial investment and a large quantity of wine because a good amount of wine is absorbed by filter pads. I’m not sure whether filtering increases the risk of oxidation. The surest way to get 100% guaranteed sterile wine is to use a cartridge filter with a sterile cylinder insert. This will easily cost well over $500. I did find a Boun Vino Mini Jet at Napa Fermentation recently. I could potentially use some 0.45 micron filter pads to achieve nearly sterile filtration.
While pasteurization or flash pasteurization will kill both the yeasts and the malolactic bacteria, it is likely to result in cooked wine, at my scale of production.
So I set up an experiment. I crushed and pressed some white (green seedless) table grapes.
I acidulated to 3.1 pH, as I’m told wines below 3.2 pH generally do not undergo malolactic conversion. I chaptalized to 25.5 Bx to allow for a target of about 13.5% ABV and about 2% RS.
After letting the mixture macerate overnight in the fridge, I added DAP and inoculated with Côte des Blancs.
I waited patiently for two days for signs of fermentation. When fermentation failed to start (the yeast was left over from last year), I started up some Pasteur Champagne yeast and pitched it. But this failed as well, leading be to conclude that table grapes must be treated with something (maybe sorbate) to prevent spoilage.
If the substance used on table grapes is, in fact, sorbate, then the failure of the table grape juice to ferment is testimony to the effectiveness of sorbate at preventing re-fermentation.
Well, at least that’s encouraging…
Unfortunately, the time to get my Fiano arrived and I had no time to experiment again with alternate juices. I had to abandon this experiment and go with my gut feeling about what will work best for my Fiano.