Mycoderma? My first try with grapes and not a kit.

[David Violante]

Hello everyone, this is my first try at winemaking with actual grapes and not a kit, and I have a question about what may be going on in the carboy. It is a concord recipe from ECKraus using local grapes from an established vineyard that I started in October 2019.

The initial SG was 1.116, pH 5.8, TA .5 before fermenting. It went through a pretty good fermentation although I had some fruit flies towards the end and on advice stopped the fermentation after about 6 days with Campden tablets in fear of acetobacter. Then the SG was 1.035, pH 5.4 TA 6.75. After several re-attempts to restart fermentation over a month or so, I finally just ended up racking it, and using nitrogen gas in the head space of the carboy.

Two months later, the SG was 1.030, pH 2.7, TA 9.75. Yikes! On advice I added 40g of potassium carbonate which brought the pH to 4.5 and the TA to 4.5. Being too alkaline I added 57g of tartaric acid. Yep. Yo-yo. It's now pH 3.8 and TA 6.75.

So... It has been racked several times and I've used nitrogen each time in the head space. In the last two rackings, there are tiny white pearls present on the surface and that stick to the sides of the carboy. I can still see a fine sediment coating the bottom. It doesn't smell bad, but it does taste a bit tart and, how do I say this, a bit mineral-ish. Being a concord, I figured it just has a ways to go. It doesn't taste bad at all, just a smidge metallic maybe.

Today I noticed a layer separation. There is a clear layer within a centimeter of the top, then another layer about 6" off the bottom, and sediment also (see attached pictures). I'm wondering what it all is? I've added a Campden tablet per gallon on each racking and have filled the space with nitrogen too. I'm considering adding potassium sorbate to coat the yeast if that's what it is, and bentonite to clear it. Not really sure at all.

Does anyone have any thoughts? I'm definitely all ears... LOL

Thank you in advance....

David

 

[David Violante]

 

[NorCal]

There are a number of things to unbundle. Your pH numbers seem to vary far greater than I’ve ever seen. May need to look into that instrument and how you are calibrating it. The single dose of nitrogen will not provide protection to your wine for an extended period of time and thus the O2 exposure. At this point I’d rack, sulfite to 50ppm and make sure the container is full.

 

[GreenEnvy22]

Was there anything else in the original recipe other than grapes? I can't see how you'd get such a high pH from just grapes. SG was super high too.

Not sure on the white stuff, maybe the carbonate.

 

[salcoco]

non dissolved tablets.

 

[David Violante]

So today I racked the wine and reduced the headspace by adding two bottles of gnarly head old vine zin (one of our favorites), let it sit after gently mixing and then tested it.

I'm using a Milwaukee pH meter and calibrated it using fresh 4.01 and 7.01 solutions. The pH after sitting was 3.8. I calculated the TA by taking a 10ml sample to which I gradually added a 0.1 N solution of sodium hydroxide. It took 6.75ml to bring the solution to a pH of 8.2. Using the calculation: (hydroxide/sample) X 0.75 = g/L, I came up with a TA of 4.6875. Which seems low.

So I also did a taste test LOL. It smells and tastes great although a little metallic/mineralish still. I haven't added sulfite yet, I don't have the equipment to test it and am not sure how I can figure it out without taking a sample somewhere. Should I just add 1 crushed Campden tablet per gallon? Is there anything I should do about the pH and TA?

 

[stickman]

First thing is that, in general, it is not good practice to add campden during an active fermentation, as the yeast will release acetaldehyde binding the campden that was added. You said you didn't add sulfite, but campden is sulfite so you did add sulfite, you also said you added a tablet per gallon at each racking which you did twice already. Is the wine just a couple of months old? If so, I'd say your're ok for now.

Because of adding potassium carbonate and then tartaric acid etc., you have a lot of potassium bitartrate in suspension, so your TA numbers now will be higher than what they will be once the wine has cleared. The metallic mineral taste may also drop off once cleared, though it may not recover fully. Just allow the wine some time to clear and see how it tastes. Did the gravity ever come down?

 

[David Violante]

Yeah, I definitely did add a bunch of sulfite to the batch so far. I hadn't really wanted to stop the fermentation to be honest. The concern by a colleague was that acetobacter from the fruit flies in the must would turn it to vinegar. So, that caused me to add the Camden / Sulfites early. Oh... The current SG is 0.996

Regardless of how this batch turns out, and I'm still hoping that it will be ok, it has been a huge learning experience. Invaluable really.

So I blindly followed a pretty reputable Concord grape recipe to the "T", since this was my first time with grapes and not a kit. Lessons learned so far:

1. Test everything before adding anything to see if you really need it. Like sugar. Or acid blend. Or tartaric acid... Even if the recipe says so.
2. Take suggestions with a grain of salt and do research on the who what when where why and how also.
3. It's only 5 gallons and if it all goes bad it's better than a barrel going bad.
4. Personal taste and preference have a lot to do with it.
5. Science.
6. And math.
7. And lots of patience

So... I feel like the acid level is ok if perhaps a little high and the TA a bit low. The batch has been at about 70F very steadily.

1. Should I add Campden / Sulfites now since I racked it (I'm thinking yes)
2. How can I figure out the sulfite level without a lab
3. Should I try to drop the acidity, which will increase the TA as well

Thanks much folks, this has been very helpful~

 

[stickman]

Campden tablets are variable depending on the supplier, check the package for the strength, usually given as weight of potassium metabisulfite per tablet, sometimes sodium metabisulfite, sometimes the label will give ppm sulfite/gal, etc. Provide the label information and someone will be able to help with sulfite addition.

Others will give their opinions, but I wouldn't add anything until the wine drops clear, you need to go primarily by taste at this point, and the taste will be affected by all of the suspended solids. Fining agents are available if you are in a hurry to clarify, but it will usually drop clear on its own.

 

[David Violante]

here's what I've been using~

 

[stickman]

So at 550mg if you added 1 tablet per gallon, that's around 80ppm, you did that twice, so 160ppm addition total, not counting the first addition during fermentation. Even if half of the sulfite bound up you still have 80ppm, just my opinion, you probably have enough sulfite for now.

 

[David Violante]

Was there anything else in the original recipe other than grapes? I can't see how you'd get such a high pH from just grapes. SG was super high too.

Not sure on the white stuff, maybe the carbonate.

Here's the ingredients for the recipe I used:
40 lbs. of concord grapes
6 1⁄2 lbs. of sugar
2 tbsp. Yeast Nutrient
3⁄4 tsp. Pectic Enzyme
1 tbsp. Acid Blend
1 tsp. Wine Tannin
1 Packet of Wine Yeast: 71B-1122

 

[David Violante]

So at 550mg if you added 1 tablet per gallon, that's around 80ppm, you did that twice, so 160ppm addition total, not counting the first addition during fermentation. Even if half of the sulfite bound up you still have 80ppm, just my opinion, you probably have enough sulfite for now.

I definitely appreciate the help~ Should I be concerned about the pH? I'm finding online that Concords should be around a 3.4 ish pH and a 6.someting TA.

 

[stickman]

The pH and TA often discussed are pre-fermentation numbers, post fermentation are often different, usually higher pH and lower TA. You said in an earlier post that the wine tasted good except for the metallic taste, so let the wine fall clear at cellar temperature and see what you have, if it tastes good leave it alone, if it needs a little more tartness then you can add some acid at that time.

 

[NorCal]

Sometime the best thing you can do for wine is nothing. You racked, topped and based on your Camden additions, you should have plenty of SO2. Leave it be for 3 months in a cool, dark place. At that point taste it again and see if any minor adjustments are needed to acid or backsweeten if you like that style.

Next time, I would not add SO2 (Camden) during fermentation. While it may suspend fermentation based on the SO2 tolerance of the yeast, that yeast could reactivate when SO2 levels drop. It’s a bad practice and leaves you with potentially unstable wine. To that point, I would make sure your carboy has a vented bung while it sits for 3 months.

 

[David Violante]

Cool beans thank you both~ I'll let it sit for a while to clear and age for a few months and then re-check it. It has a vented bung on it now so I'll leave that in place. I appreciate all the advice and help!

 

[David Violante]

UPDATE:
I has been 10 days shy of a month since I racked the wine. I topped it off with a couple bottles of reputable zinfandel, and maybe 500 ml of water. I did not add any sulfite. Here's a picture of what's happening at the top of the container. I'm thinking I need to rack again, and add sulfites. I could try to get a sample of these things and see if I can find a microscope somewhere, but I'm not sure I can find one. I don't have a filter kit, unless I make one from a whole house filter with a very small micron cartridge. It's sitting at about 60 degrees in a cool dark place with a vented bung attached that is half full.

 

[David Violante]

 

[stickman]

My guess is that the material at the top is tartrates possibly combined with a protein precipitate, which is not much of a concern at this time. Excessive racking will do more damage than good. I would rack if you have a sulfide aroma associated with heavy yeast lees, otherwise allow to settle clear. The recipe did include some tannin which should help with protein precipitation, but in the end may not be enough. Just relax and allow time to work for now, again you can use fining for clarification if you are in a hurry, but otherwise relax.

 

[sour_grapes]

View attachment 59370

I was concerned about that picture until I realized you used Campden tablets. I imagine that junk is from the binder in the Campden tablets or not-completely-crushed bits of Campden tablet.