Stuck ferment, restart failed

[Univox360]

I can’t seem to get my wine past dropping only 1 brix every few days. I’m stuck at Brix 13 on day 16 which is a lot of sugar content still. At day 14, I tried a restart protocol with EC-1118 yeast and a starter volume but this has also failed to get going despite all the yeast hydration nutrients etc. and following strict protocol. not sure what do do now. Full details below:

16 days ago I received some primitivo grapes about 600 lbs. grapes came in the heat wave and had some raisins etc, but I wasn’t allowed to sort before crush. I had to ameliorate to drop the sugar and acidulate to raise the pH, but things came out to a good range initially. I inoculated with a BDM 45 using a dry pitch and got an initial ferment that was quite vigorous. Unfortunately during the heat wave I didn’t have great temperature control and the ferment hit 92F overnight on day 3 or 4. In the morning I dropped some sanitized ice jugs and got things down to below 86 within 12 hours but the damage was done. The brix kept dropping but now slowly and the high heat gave a ‘sharp’ acidic smell a few days later meaning the VA is too high.

At 1/3 depletion I hit it with some nutrients, but still the brix was still moving down way to slow. At day 12 I added Reskue or yeast hulls. Then on day 14 I added lysozyme and bumped the SO2 back up. I drew off about 7 liters from 220 liters and created a starter volume. I used the yeast hydration nutrients and Fermaid O according the the attached protocol. But now at day 16 my starter is ticking along just as slowly as My wine was. No strong ferment. Restart protocol I used. Only thing I didn’t folllow was not using uvaferm 43, but ec-1118 can also be used for restart.

https://www.lallemandwine.com/wp-content/uploads/2019/01/WE-9-Stuck-Fermentation.pdf

There aren’t any off flavors and the wine , although too sweet, has good flavor although it needs to aerate a bit for the VA to flash off.

What to do next? New starter? I’m worried it’s a lot of wine going to go to vinegar.

Thanks!

 

[stickman]

It looks like you're not alone in this situation. Scott Labs has indicated receiving many calls during the current vintage; they don't know the source of the problem yet, but offer the following guidance.

https://scottlab.com/managing-high-volatile-acidity-in-red-grapes

 

[sour_grapes]

How are you measuring your Brix? Refractometer or hydrometer?

 

[Univox360]

Refractometer. BTW I’m still on the skins. Should I press?

 

[CDrew]

That is a lot of wine so you have to try again! And, that's what I'd do. You have nothing to loose.

I'd make a new big starter with maybe 100g yeast and GoFerm. Then add your existing wine stepwise to it, so the starter becomes the primary fermentation. Be generous with additional Fermaid O. Do not add more SO2 until it's complete as I suspect that is what is causing the problem. Do you know your SO2 level?

As to what yeast to use, tough call. From reading your source, the Uvaferm43 restart sounds pretty good on paper.

Good luck and post up what happens.

edit: Leave on the skins and use a hydrometer to monitor progress.

 

[sour_grapes]

You cannot (easily) use a refractometer to monitor fermentation. The alcohol has a different refractive index than water does, and so it skews the result to make it appear to have sugar in it.

See more here: - ValleyVintner Main Page

 

[Snafflebit]

Zinfandel, Primitivo is famous for stuck fermentations. You don't say what your starting Brix was. With raisins in the must your Brix is surely even higher. It may be worthwhile to figure out if you need to add some water to the batch. I am using BM45 this year and it will stick at 16% alchohol and needs nutrition and DAP in my opinion. And definitely buy a hydrometer and measuring jar

 

[Univox360]

Brix started at 27 after amelioration

 

[Univox360]

pH started at 3.56 and crept up to 3.65
TA started at 7g/L and crept up to 8.4g/L (a lot!)
I’ll try to correct the refractometer readings and send later for more accurate measure

 

[Snafflebit]

I have grapes this year that were 29.5 brix after a cold soak. The must contained a few raisins, mainly shrivel. In order to target 25 Brix with water addition, there is an undershoot. You can see my experience this year in the link below. The heatwave was a big problem in California. Step one is to make sure you measure Brix with a hydrometer

2022 Cab growth starting off great.

 

[CDrew]

Zinfandel, Primitivo is famous for stuck fermentations. You don't say what your starting Brix was. With raisins in the must your Brix is surely even higher. It may be worthwhile to figure out if you need to add some water to the batch. I am using BM45 this year and it will stick at 16% alchohol and needs nutrition and DAP in my opinion. And definitely buy a hydrometer and measuring jar

I have seen that said many times, but it is not my experience. I've made Primitivo each of the last 6 years. I did have to water back once(2021) from 27 brix to 25 brix. I've never had a single problem with a stuck or incomplete fermentation. Yeast used: D254, D21, Avante x2, Bravo x2.

For @Univox360 go buy a hydrometer this morning. They are cheap and will help you obtain accurate numbers with no calculations needed. That high brix is borderline for most yeast strains, especially if there were raisins in the must.

Unrelated question: Anyone tried to restart a stuck fermentation with Avante? It's an extremely robust yeast with excellent high temperature/high alcohol tolerance. It seems like it should be an appropriate strain to use.

 

[Univox360]

I'll get a hydrometer as soon as I can.
From the alcohol correction chart (putting in starting Brix at 27), I get an actual brix of about 5.6.

 

[Raptor99]

If your original Brix was 27 and the current Brix is 13, then the current SG is 1.013. (See the calculator here: Homebrew Refractometer Calculator) The actual Brix is the Brix that you measure with the refractometer. But you need to calculate the actual SG once fermentation has started.

Fermentation is not finished, so if the Brix doesn't change it is probably stuck. The original Brix of 27 would give a potential ABV of 16.7%. Many wine yeasts would stop before that. EC-1118 has an alcohol tolerance of "up to 18%" "depending on conditions." (Lalvin EC-1118™ | Lallemand Brewing).

Once the measured Brix is down to 10 and holding there, the SG would be 0.994 and the fermentation would probably be finished.

 

[Univox360]

So I'm reading 14 now Brix for my main ferment. Not sure what the difference is about from 13 measured earlier, but this puts me at a specific gravity of 1.022 according to my calculations.

For my starter ferment with EC-1118, I am getting 12.5 Brix after pitching on Friday. This puts me at specific gravity of 1.012.

Hydrometer comes tomorrow and I'll double check.

Clearly the starter is going... but not strong. Should I start over with Uvaferm restart anyhow and pitch that using a different starter setup? EC-1118 is clearly not going very fast.

 

[Univox360]

Also, at which point to add the restart to the main ferment? I have heard a suggestion of 1.000 SG

 

[winemaker81]

Also, at which point to add the restart to the main ferment? I have heard a suggestion of 1.000 SG

You've got a high brix must and the finale is not necessarily going to go quickly. The yeast poisons its own environment with alcohol, so things slow down, and the BM-45 may have hit its limit. If you are seeing progress in the starter, then it is working. I'd add it now, as you need to get the main batch working as well.

How many packets of BM 45 went into the original, and how many EC-1118 into the re-starter?

If it were me? With 600 lbs of grapes I'd make an overnight starter with 5 or 6 packets of EC-1118. Start with 3 cups of 95 F water, add 1 tsp nutrient, 3 Tbsp sugar, and the yeast. Stir to blend and cover with a towel. Leave it in a warm place for a few hours to ensure it's working, then move to the fermenting area. The temperature of the starter will adjust to the area temperature, so you won't have a temperature shock when adding the starter to the batch.

The next day, carefully pour down the side of the fermenter so the starter spreads as little as possible. Yeast supposedly reproduces faster in larger groups. I've been making overnight starters for over a year, and they consistently make a fast start. The yeast is in an environment more ideal for it (95 F is too hot for grapes, but the yeast loves it), and quickly produces a much larger colony.

Unrelated question: Anyone tried to restart a stuck fermentation with Avante? It's an extremely robust yeast with excellent high temperature/high alcohol tolerance. It seems like it should be an appropriate strain to use.

I haven't tried Avante for restarting a ferment, but based upon the description I'd try it. Except in very high brix musts, it should work.

 

[Univox360]

I dry pitched 60g of BM-45 initially with no nutrients (whoops).

For the starter, I hydrated 80g of EC-1118 in 0.88L of water with fermstart. I added 4.4g of Fermaid O to the starter volume (7.5L). Then introduced the wine slowly to the foaming yeast vessel. Because I thought my sugar was higher than it was, I did not add sugar unfortunately.

I agree about adding the starter sooner than SG 1.000. Better the yeast in the starter get tp the main ferment before the alcohol reaches toxic levels.

 

[Univox360]

So I added the starter to the main ferment this afternoon. Main ferment gives SG of 1.020, about what I calculated from the Brix and equations earlier. We'll see how things proceed now that EC-1118 is working on things. I have some Uvaferm as a backup just in case.

Just curious, since this is all taking so much longer than expected: I am doing this in a 300L marchisio tank (220L wine). I use the lid, but just sitting atop with the airlock hole loosely covered with plastic wrap. So there is 80L of headspace. Should I be flushing with nitrogen and/or pushing the lid all the way down to prevent oxidation and spoilage?

Thanks everyone!

 

[winemaker81]

Just curious, since this is all taking so much longer than expected: I am doing this in a 300L marchisio tank (220L wine). I use the lid, but just sitting atop with the airlock hole loosely covered with plastic wrap. So there is 80L of headspace. Should I be flushing with nitrogen and/or pushing the lid all the way down to prevent oxidation and spoilage?

During fermentation the yeast needs O2 for reproduction, so there is not an oxidation problem. After fermentation, O2 is the enemy.

Most of us cover the fermenter with a towel, just to keep stuff out, while letting air pass through.

 

[Univox360]

I added the EC-1118 starter 5 days ago (Tuesday). Three days ago I measured specific gravity at 1.013. Today I am getting around the same, maybe 1.0125 if I am being generous. BTW to get an accurate SG I found I had to lightly "blend" the wine in a blender and filter it through a coffee filter.

Seems stuck again. I have quite a bit of ways to get to dry....

I have the Uvaferm yeast as a backup. Should I pitch it to restart again? Or give the EC-1118 more time? Seems like it will never get there at this rate.

Thanks!