Help Fermentation wont start

[Handy Andy]

Help please > Fermentation refusing to start !

I harvested and pressed 30 litres of Alverino white wine grape juice on Saturday. Added sugar and Potassium Metabisulphate then waited 24 hours and added yeast Enartis ferm SB saccharomyce cerivesiae + Nutrient Enertis Nutriferm Special.

After 24 hours the grape juice had not started fermenting so I added more yeast. 24 hours later nothing is happening.

I carried out a test last night, with just yeast and sugar and the yeast reacts strongly within 5 minutes. I then carried out a further test with yeast + sugar +additive and nothing happens.

I think the nutrient is killing my yeast. Can last years nutrient go bad?

Is there anything I can do to start my grape juice fermenting, with a nutrient that appears to stop my yeast from working?

Is there any mileage in adding bentonite waiting for the juice to clear then racking the juice and trying again with yeast?

Edit mg SG is 1.100 and has not changed since I added sugar on saturday.

 

[Handy Andy]

Pitched more yeast mixed with warm juice and water this morning, after an hour I can hear bubbling in the barrel, I might have fixed the problem. I used 4 times more yeast than recommended on the packet, then added some more for good luck.

 

[Johnd]

Yeast may take 72 - 96 hours to show visual signs of fermentation, depending upon the condition of the yeast, must, temps, etc…. What you’re probably seeing, is your first yeast pitching getting going, albeit with colony size help from the subsequent pitching.

 

[Handy Andy]

Yeast may take 72 - 96 hours to show visual signs of fermentation, depending upon the condition of the yeast, must, temps, etc…. What you’re probably seeing, is your first yeast pitching getting going, albeit with colony size help from the subsequent pitching.

Its possible, there was no bubbling before I pitched again this morning. Is their any chance the nutrient I added could have killed of the first lot of yeast?

 

[Johnd]

Its possible, there was no bubbling before I pitched again this morning. Is their any chance the nutrient I added could have killed of the first lot of yeast?

I’ve never had an instance where this occurred, nor heard of one. If you used nutrients intended for winemaking, in proper dosage, it seems very unlikely. You did, however, have a pretty healthy sugar content at 1.100+, that can make a difference. The yeast sense the sugar level in a must, and first reproduce to create a colony that is properly sized to handle the task at hand, this is what we refer to as lag time. Your dudes were just taking their time.

 

[Rice_Guy]

* the first phase of yeast growth is budding new cells in the presence of oxygen, I assume your bubble are in a brute/ pail with air, ,,, not in a carboy under air lock.
* your SG of 1.100 is a stress, ought to work but not optimum and the yeast will take a while to acclimate, step feeding is less stress on the yeast
* when this happens again, you can do a restart procedure with yeast sprinkled on a sugar water > add a little juice > add more juice
* as John said visual bubbles is not necessarily going to show anything for a few days, the yeast companies specifically select strains that have low production of foam/ byproduct chemicals that enhance stable long lasting bubble structure, it will take a while for byproducts to accumulate
* temperature is part of the equation, yeast will have an optimum and their growth typically decreases rapidly with ten degrees more temp and decreases gradually as the temperature is lowered. When I run controlled temp I start with a day at room temp to build up a cell population.
* nutrients are basically chemicals, they should have a long shelf life of years unless they are wet or exposed to heat that causes them to char
* the viable cell count in the dry yeast decreases if the packet was at room temp or warmer, it is best to keep yeast in the fridge

 

[bluecrab]

I read on another thread that if you rehydrate yeast with nutrients not meant for rehydration, it can kill them. I’m not sure if this is true or if it is your problem, but it is a possibility.

 

[salcoco]

nutrients are usually added after fermentation has started. it may be possible that using them at start overwhelmed the yeast. check with the supplier

 

[sour_grapes]

Well, let me also ask how much potassium metabisulfite you used for the 30 L of juice? If you used too much, that may have inhibited the lift-off.

 

[Handy Andy]

Well, let me also ask how much potassium metabisulfite you used for the 30 L of juice? If you used too much, that may have inhibited the lift-off.

On the packet it said 10 to 30grams/100litres so i gave it 10 grams 2 teaspoons. Maybe it would have been better to give it 5grams

Edit I think you may have hit the nail on the head !

 

[winemaker81]

Normal K-meta dosage is 1/4 tsp per 19-23 liters, so 2 tsp for 30 liters is WAY high.

 

[Handy Andy]

Normal K-meta dosage is 1/4 tsp per 19-23 liters, so 2 tsp for 30 liters is WAY high.

Er Yeah I wondered about it as I dosed, because last year I dosed at 50ppm or 1 teaspoon / 100 litres.

In Conclusion I added nutrient before the yeast had started and added way to much k-meta to the juice. Both of which could have slowed or even stopped the activation of the yeast.

Hopefully I have got away with it.

 

[KGREZLIK]

First timer here- Started with a 7.9 Fasterferment, 6 gal wine expert chilean cab kit. Went through the process yesterday, it has been about 27 hours, should the airlock be bubbling? Will the 3 piece airlock used in the fasterferment show bubbles? I am not overly concerned, room temp is about 67F, but at what point should I go to plan B, and what should Plan B consist of? The kit was fairly expensive, about 90$ and I would hate to give up on it- can this be rescued?

 

[Rice_Guy]

Not always.
Bubbles indicate lots of yeast activity and could be encouraged on the lab bench at 110F. We are making wine though so flavor rules control the fermentation.
I have used an Australian yeast that took four days to show bubbles and by day six it had as much foam as liquid. ,,,, you can get better bubbles with yeast that produce chemicals that stabilize foam, ,,, but again it was an inconvenience to clean foam off the table and such.
It sounds like you have the primary under air lock. The initial phase of yeast growth requires oxygen and frequently is an open bucket with a towel over it.

plan B usually is wait longer

 

[winemaker81]

@KGREZLIK, relax. Winemaking is an exercise in patience.

Typically, fermentation is visible in 24 to 72 hours. However, you have several factors slowing the yeast down.

While 67 F is not a cold ferment, temperatures less than 70 F are likely to slow the yeast down. And as @Rice_Guy said, yeast wants O2 for reproduction, so a sealed container slows that down.

What yeast did you use, and how did you inoculate? Did you pitch the yeast on top of the must? An open container with a temperature between 72 F and 78 F give the yeast the best starting environment.

I'd give it another couple of days. However, you can create a yeast starter with another packet of yeast. Start with 1 cup warm water (85-95 F), add 1/4 tsp yeast nutrient and 1/2 tsp sugar, then add the yeast. Set aside for 18-24 hours. It should show signs of activity. Then gently pour into the fermenter in a slow stream, preferably along the side of the container so the starter doesn't spread much.