David at Palatine Hills recommended I try Bocksin (with CombiGel later) to combat the off-odours in this year's Gewurzt. The standard dosage rate is 30ml per 20L of wine, so I added it directly to one of my two carboys, without doing any trials. I figure that at the very least, it's not going to hurt it...
In a week I'll add 5ml of CombiGel (a fining agent) and let them both stand for 3 weeks before sterile filtering.
I got another wine-related birthday gift this year, the Buon Vino SuperJet filtration system. This was something I've been eyeing for awhile, so it came at a handy time. So tonight I tried it out on the 2006 Gewurztraminer, as this is the stinky one and could use filtration the most.
Using all 3 sizes (coarse, polish, and sterilizing) I filtered two 23 l carboys in about an hour. Capacity is actually much faster, but I had to clean containers between use and figure our how the whole system works.
It works quite well. The wine is crystal clear now, and still retaining that telltale reddish tinge you get sometimes in Gewurtz. The off odours are still present in the wine, but they're noticeably reduced.
I made an addition of 12ml of 10% SO2 solution (per 23 litre carboy) in order to bring free SO2 up to 30ppm.
The second batch of Riesling was racked today, so the fermentation process is now officially over. Both wines are now racked to tank, and all we can do now is wait and rack every six weeks or so for the next 6 to 8 months.
I racked the last 45L or so of wine into two carboys, one 23L and one 20L. There wasn't any left over for topping, so at my next racking, I'll move the 23L bottle over to a 20L and use what's left over to top up the other containers. That should be alright.
Depending on outside variables, this is the schedule I'll try to stick to:
1rst racking: Christmas vacation
2nd racking: Mid-February
3rd racking: start of April (I'll add fining agent at this time, if required)
4th racking: Mid-may
Bottle: start of July.
After a few days of incredibly overpowering VA odours on the Gewurzt, things might finally be starting to come together a bit. The BA11 is even more wretched (rubbery-smells now), but the R2 *may be* starting to pull itself out, and a little bit of fruit is starting to show through again.
Here's what I've learned: Sasha said most-often VA will form in the early part of a fermentation, and then blow off as the fermentation progresses. So on Sunday, I stopped cooling both bathes to allow the fermentation to speed up and start doing its thing.
I also wanted to now what racking off the lees would do at this stage (sometimes off-odours reside in the lees), so I racked the smaller batch - 15L of BA11. This turned out to be a bad idea, as I've since read that the increased oxygen interaction when VA is present is a terrible idea. OK, chalk that one down in the "good to know" department.
Here are Saturday's numbers:
R2: 5°B @ 52°F
BA11: 8°B @ 56°F
And Sunday's numbers:
R2: 4.5°B @ 56°F
BA11: 7°B @ 57°F
And Monday's numbers:
R2: 3.7°B @ 64°F
BA11: didn't take...
One or two days after fermentation began in earnest, off odours started occuring in both batches of the Gewurztraminer.
Initially, I thought it could be a lack of yeast nutrients that was causing sulfur to form (there was a slight rotten-egg smell) and I compensated by adding a second dose of Fermaid K.
The next day the sulfur smell was gone, but other off-odours remained, and the wine started taking on a bitter, 'soapy' taste that was unpleasant. I recalled this happening a bit with my 2004 Viognier, and that wine worked out just fine, so I ignored the issue and assumed it was some VA, and it'd burn off as the fermentation progressed and dissipate further once racked off the lees.
Unfortunately, I'm now starting to think it could be either a REALLY bad case of VA, or some other type of nasty bacteriological infection The juice is now sporting a tremendously bitter taste, and the off-odours are overpowering whatever fruit might be there.
I'm not sure what, if anything, can be done at this point to pull the wine in the right direction. My best guess is to just let fermentation finish, and then hit the wine with a good dose of SO2 and rack it (with as little oxygen interaction as possible) as soon as I can.
So what have I learned? Unfortunately, I'm not sure. The vineyard I purchased the juice from hit the juice with 50ppm of SO2 at crush, so I couldn't add any more of that. I used some well-fermenting yeasts, and I used adequate yeast food. (Perhaps too much yeast food? Is this just a nasty yeast and fermentation smell?)
If anyone has any other ideas, please let me know.
On the brighter side, the Riesling is not exhibiting any such odours or tastes, and fermentation is coming along nicely. I am concerned that this wine may also encounter fermentation problems, but I'm crossing my fingers.
The rate of fermentation is starting to drop off a little now on the R2, having only dropped 2 Brix over the last day. The BA11 is maintaining a consistent rate (also 2 Brix). By adding more icepacks to the demijohn of R2, I've done a good job of keeping the must cool as well, it's now down to 57°F.
Here are today's numbers, taken at 2:00pm:
R2: 5.5°B @ 54°F
BA11: 9°B @58°F
The Gewurztraminer is about half done with fermentation now, and slowing down from the rate it was at over the last couple days.
I've also moved the demijohn of Riesling outside onto the porch now, which frees up more icepacks for the demijohn of Gewurzt, so I can try and keep the temperature down. I'm now rotating 4 icepacks on it every 3 hours or so and I hope it helps lower temps back down to around 60°F.
Here are today's numbers, taken at 1:00pm:
R2: 7°B @ 64°F
BA11: 11°B @ 56°F
The smaller carboy with BA11 is staying significantly cooler, and this is doing a good job of keeping the fermentation rate down. The demijohn however is now above 60°F and hard to tame.
Here are the current numbers @ 2:00 today:
R2: 9.5°B @ 63°F
BA11: 12.5°B @ 52°F
The fermentation is starting to speed up a little. I'd prefer it to stay slower, but I don't have a good way of keeping the demijohn cool (I'm currently rotating 2-3 icepacks on it all times, but it's not really sufficient).
The off-odours from yesterday are still persistent, despite the addition of more nutrients. This leads me to think the problem might not be sulpher, and could be VA or something else. the taste is getting slightly "soapy" and bitter as well.
I seem to remember this happening to my 2004 Viognier as well, and it all went away during the aging process, but these odours and tastes are not particularly pleasant right now.
Here are the numbers at 2:00pm today (note, I had to switch to my wide-range hydrometer, which is less accurate, because it's out of range of my high-end):
R2: 13.3°B @ 62°F
BA11: 14.7°B @ 59°F
I also added the second dose (third in the R2) of Fermaid nutrient additions. 1/2 a teaspoon in the BA11 and 1 teaspoon in the R2.
The fermentation is progressing slow and steady, just as I was hoping. We're now dropping about 1-2°Brix every day, which would mean this fermention should last about 1.5-2 more weeks.
Also, I noticed a whiff of sulpher on the big batch of R2, so I added another 1/2 teaspoon of Fermaid K to provide more nutrients. I'll have to go back to my notes to see how much I've already added and make sure I keep track of all the nutrients I've added so far.
Here are this morning's numbers:
R2: 18.2°B @ 60°F
BA11: 17.6°B @ 58°F
Fermentation started in earnest today, with each batch of must dropping about one Brix. I also started chilling these down again, this time to about 58-60°F.
I also added Fermaid K to the must, in order to provide yeast nutrients. I added 1/2 a teaspoon to the 15L of BA11 and 1 1/2 teaspoon to the 45L of R2.
Numbers now stand at:
R2: 20.5°B @ 58°F
BA11: 21.8°B @ 60°F
We don't seem to be having much in the way of fermentation this morning. Temperatures are holding steady around 60 degrees, and the brix haven't moved at all.
45L of juice in Jemijohn with R2 yeast:
21.3°B @ 58°F
15L of juice in carboy with BA 11 yeast:
21.3°B @ 60°F
I'm not worried yet, it's still early in the process and the juice is fairly cold. That said, I'd like to see some movement start soon, so I've taken off the cold packs to allow the juice to warm up to room temperature for the time being. Once I see the brix start to move, I'll cool the must back down.
I poured the final 20L of juice into my fermentation vessels this morning. I kept this last bucket outside overnight in order to keep the temperature down while the juice inside was left at room temperature for the yeast to get a hold and start working.
For the rest of the day I've tried to keep the must as cool as possible so that fermentation can proceed slowly for the next few weeks. It's now been 20 hours since inoculation and I've started seeing small bubbles appear, and a bubble is pushing through each airlock every 5-10 minutes or so. This slow-start is pleasing.
I've currently got the juice in two containers (a 20L carboy and a 60L demijohn) and I'm cooling them with a couple different methods:
The carboy I've placed in a small rubbermaid bin, which is one-quarter filled with water. Every two or three hours I've been rotating in a small icepack, which is keeping the water temperature around 58 degrees. The must should be slightly higher, and I'll check that tomorrow morning, when I check brix numbers.
The demijohn is much bigger than the carboy, so I've got it wrapped in some blankets, with two icepacks secured against the side of the glass with with some insulating neoprene. These icepacks stay frozen for about 5-6 hours, so I'm rotating them about that often. Again, I don't know how cold exactly this is keeping the must, but I'll check tomorrow morning when I check the brix.
I inoculated 2/3rds of the Gewurzt juice this evening around 9:00. I did about 15 litres with BA11 and 25 litres with R2. Tomorrow morning I'll dump the rest into the two containers I'm using. I'm leaving this portion outside because it's arouind 10 degrees C and I want to keep the must as cool as possible.
I also bought a new high-end hydrometer todaym, and did my own measurements: I got 21.2 brix (at 62 degrees) which is pretty close to the numbers David gave me on the phone yesterday.
Before inoculation I did some acid adjustments. The must had a TA of 6.4, which I wanted to raise to 7.0. Given that 1 gram of tartaric acid will raise 1 litre of must by .1, I added 36 grams of tartaric acid to the must. (.6 * 60 = 36).
Today I picked up 60 litres of Gewurtztraminer juice from Palatine Hills Estate Winery in Niagara-on-the-lake.
The grapes were picked Sept. 27, and allowed to rest 6 hours on skins with some enzymes before being pressed. As I was in California at the time, helping with Eno Wines' harvest, my share was set aside in three 20L buckets and put in cold storage until I could pick them up today.
The inital numbers look fantastic:
- 21.8°B
- 6.4 g/L TA
- 3.52 ph
The only concern is that the TA is a little low. As I'm aiming for an Alsacian-style white, I'll probably raise this to .7 in order to give it a little more 'spine.'