Has primary fermentation ended?

[Crusado]

Hello everyone, I'm a first time poster and first time wine maker living in South Louisiana. Using Black Spanish from my backyard. Rain almost every day and afraid I was going to loose them. Very low sugar and very high acid. Got only 1 1/2 gals must. Blended sample tested 16.5 brix, 3.86 ph, 16.1 g/l TA using refractometer, ph meter, and NaOH acid test kit. Added 10.5 oz sugar to target 23.5 Brix. Did not adjust for pH/TA hoping test was somehow off (I know. Not good science) and that MLF will correct. Did not retest after sugar correction either and assumed starting brix of 23.5. Added 50 ppm KMBS on 7/26 mid-afternoon and pitched ICV-D254 w/ Gofirm 7/27 late afternoon. Cap already formed early next morning 8:30 7/28, punched and added first does Fermaid K. Punching 3 time daily. Brix using refractometer and Temp are as follows:
7/28 8:30 am - 20 brix - 75F
2:30 pm - 19 - 77
10:30 pm - 17 - 80
7/29 7:00 am - 14 - 81
3:30 pm - 11 - 81
12:00 pm - 9 - 79.2
7/30 9:00 am - 7.5 - 77.2

I'm using an excel spreadsheet to compensate for the refractometer and alcohol which is claiming my sugar is at -2.8 brix. This seems to have happened way too fast. Is my primary fermentation finished? Will sugar continue to drop? I thought it would stop at zero and I would press and move on to MLF. Do I let it go till sugar stops falling? WHAT THE HELL!?!?? Also haven't tested pH or TA again. Will do so after pressing. Any help would be greatly appreciated.

 

[M38A1]

Being new myself, I can't speak to the conversion of the refractometer with alcohol present. What I've learned is trust a hydrometer for SG if you have one as it's not affected by alcohol content. I have two now since everyone says "get two as you'll invariably break one at the worst moment". And testing pH in the presence of CO2 which is being off-gassed during PF will also skew the pH number from what I am reading here.

More to your question, from the few batches I've completed, that compressed timeframe doesn't seem right to have consumed 100% of the sugars.

 

[Johnd]

I'm also in south Louisiana, small world, what city are you in?

I've had grape batches finish as quickly as 4 days, but you really should get a hydrometer for testing after fermentation has started, I don't trust refractometer adjustments. The rest of your process looks pretty solid, I'm curious to hear what your hydrometer readings are when you get one.......

 

[Crusado]

I'm also in south Louisiana, small world, what city are you in?

I've had grape batches finish as quickly as 4 days, but you really should get a hydrometer for testing after fermentation has started, I don't trust refractometer adjustments. The rest of your process looks pretty solid, I'm curious to hear what your hydrometer readings are when you get one.......

 

[Crusado]

I do have a hydrometer. Just thought the refractometer was as accurate and oh so easy. Stealing a couple of drops at each punching sure beats having to dredge up 100 ml or more. I will check sugar via hydrometer shortly and post. I am in Lockport which is on Bayou Lafourche 15 miles or so east of Houma. Yes small world, and hopefully bigger harvest in the future. I’ve only got 2 vines now but my cuttings are thriving and I will plant 6 more in the spring.

 

[Johnd]

I do have a hydrometer. Just thought the refractometer was as accurate and oh so easy. Stealing a couple of drops at each punching sure beats having to dredge up 100 ml or more. I will check sugar via hydrometer shortly and post. I am in Lockport which is on Bayou Lafourche 15 miles or so east of Houma. Yes small world, and hopefully bigger harvest in the future. I’ve only got 2 vines now but my cuttings are thriving and I will plant 6 more in the spring.

Yes, it's a lot easier to use, the hydrometer is more work, just have a lot more faith in its results.

I know exactly where Lockport is , pass through there to fish down in Grand Isle and Port Fourchon.

 

[mainshipfred]

I know exactly where Lockport is , pass through there to fish down in Grand Isle and Port Fourchon.[/QUOTE]

Your numbers are growing rapidly down there. If they keep growing you may see a Northern invasion.

 

[Crusado]

Brix via hydrometer is 1.00985 @ around 4 pm-ish. Guess I'm not there yet. Non blended juice sample was 76.5F, pH 4.0, TA 12.3 g/l. Should I still press @ Zero despite the quick drop?? Why is the refractometer method with the spreadsheet off? Are there any other signs I can use to know it is ready? Was I wrong to blend original test sample? I'm hoping MLF will bring TA down but will it increase pH even further? WHAT THE HELL!?!?!! I feel like I'm preparing for the birth of my first child again.

 

[Johnd]

I know exactly where Lockport is , pass through there to fish down in Grand Isle and Port Fourchon.

Your numbers are growing rapidly down there. If they keep growing you may see a Northern invasion.[/QUOTE]

You northern boys come on down here, we welcome all who aren’t afraid to melt.......