Primary was great, Secondary now stopped after racking?

[we5inelgr]

Ok, this question/situation, clearly, is the result of being a 1st time vintner

I've got 3 batches of wine (Pinot Noir, Petite Sirah & Cab Sauv), all from fresh grapes, that appear to me to be stuck during what I believe is considered the secondary fermentation period.

Conditions for all 3 batches:

• Had a starting brix of between 23 and 26.
• "Cold" soaked for 3-5 days at 65F in a cold box. (50 ppm SO2 added at beginning)
• Inoculated with yeast:
  
  1. With appropriate alcohol tolerance.
  2. Per package instructions.
  3. Using Go-Ferm
  4. Waited till temp of yeast slurry was less than 18F difference (~20 min).
  5. Mixed in about 1/2 volume must into yeast slurry.
  6. Waited ~5 minutes, then pitched.
• Primary fermentation started up and was vigourous, temp ~78F.
• Fermaid K was added at the beginning, and at about 1/3 brix drop.
• All batches continued for 5-7 days.
• When primary fermentation slowed considerably, checked SG:
  1. All were between 1.0237 and 1.0298.
  2. Independently (not all on same day or time), I racked the juice off the skins into carboys with airlocks and place them in a temp controlled box at 75F.

Now, several days later, there is zero activity observed (not even very tiny bubbles) and the SG readings appear the same.

I'm starting to wonder if this secondary fermentation phase is stuck...for all 3 batches.

The concern here is waiting much longer to see if anything happens because (1) this is my first vintage, so I'm not sure how to gauge this stage and
(2) the grapes may not have been ideal, not visibly filled with mold, etc ... just that the vineyards were not kept up the best they could and I suspect high levels of bacteria / native yeast due to a bit of finger nail polish smell coming from at least the P.S. batch.

All batches smell pretty good at this point (no more nail polish remover smell).

Perhaps I left behind too much of the initial yeast inoculation when I racked into the carboy's?

Perhaps there is still too high level of native bacteria in the juice, competing for nutrients?

What are some suggestions at this point? Use lysozyme "just in case" and then pitch a new yeast inoculation? I do want to do a MLF using a commercial strain on all 3 batches.

I guess my bottom line question is, what would be the negative effects of adding lysozyme first and then pitching more yeast?

Any thoughts or suggestions would be greatly appreciated!

Thanks!

P.S. For reference, my other thread regarding the "finger nail polish" smell on the P.S.

 

[stickman]

Are you saying the wine is stuck at 1.02 sg? Lysozyme will not have any negative effects on yeast, it only works on bacteria. Take a look at this restart guide that may help.

View attachment 2010RestartStuck.pdf

 

[we5inelgr]

Yes, the wine seems stuck at 1.02 sg. In the case of the Cab Sauv, it hasn't moved in about 5 days. Pinot Noir for about 3 days. The P.S. is the newest racked off the skins and the sg has remained the same for 1 day. Not as concerned about that, but I'm thinking in 3-5 days, the C.S. and/or the P.N. should have moved some.

I looked at the restart guide. Thanks for the reference. Seems overly complex...but, they are experts so what do I know

Anyway, I might experiment a bit and simply add lysozyme for potential native bacteria, then adding a "stuck" yeast fermentation procedure.

Thoughts about doing the MLF now (even though brix is ~6 -7), and the after it's done, follow-up with a healthy "stuck" fermentation procedure to go to dry?

 

[stickman]

It would not be a good idea to start MLF now. It is best to get the sugar converted first. If you add Lysozyme, don't exceed 150ppm. If you have yeast hulls on hand, the addition of .3 to .5 g/l before adding the next yeast starter is helpful.

 

[Arne]

Are your temps. still up there? If not get em up to mid to high 70's. Bet you left too much of the yeast when you racked, but there should still be enough to finish out. Might be slow, but should finish. Arne.

 

[pillswoj]

Are you using an hydrometer or a refractometer to measure sg? refractometers are not accurate in once fermentation has started.

 

[we5inelgr]

Are you using an hydrometer or a refractometer to measure sg? refractometers are not accurate in once fermentation has started.

Ookkaayy, upon further review...my status as a newbie vintner is solidly confirmed.

I had read that if one uses a refractometer during (or after) alcoholic fermentation, one must make adjustments. Well, I had totally forgotten about that.

Eventually, I'll get a hydrometer. The need for 250ml samples turned me away at first due to my limited quantities of grapes/must. Guess I could alway put the sample back after taking readings (assuming the hydrometer is sterilized first).

Using the conversion calculator found at Northern Brewer, it looks like all of my batches would be considered dry.

Example. Petite Sirah starting brix 24. Current brix reading (using refractometer) is 6. The corrected SG is approximately 0.977.

According to winemakersacademy, OH fermentation is considered done when final S.G. reads about 0.996.

Another site, talks about S.G. readings that go below 1.000.

So, according to all that, it looks like my primary fermentations for all batches is probably done.

Onward to MLF and thank you again to all who responded with info and suggestions. As always, it's greatly appreciated.

 

[stickman]

@pillswoj good catch!

 

[Scooter68]

Using a Hydrometer does not require a 'disposable' sample of your wine. Just sanitize the hydrometer before use, then rinse and sanitize again before storing it. You just develop a simple routine for taking the sample with clean/sanitized equipment and then returning it to batch. Actually I do both the SG tests and the pH testing with the same sample to save time and effort.
The only time a sample could not be returned to the batch is if you do a TA test with it and that requires very small sample.