WineXpert Fast vs. Slow fermentation

[Rocky]

I would like to hear the forums views on the benefits or issues with fast vs. slow fermentation. I am making four kits which I began on 2-3-25. The next morning, the fermentation was unimpressive but my cellar temperature was in the mid 60's F and I thought temperature could be a factor. I added heat to two of the fermenters and the process really took off. Today, 3 days after starting, one of the wines with heat had dropped from SGi 1.092 to SG 1.013 so I racked the wine off its residue (grape skins and oak powder and chips, etc.) into a 6 gallon carboy and added an airlock. I don't see a problem with this but I would like to throw it out to the community. Two other wines were SG 1.035 or so and will likely be below SG 1.020 by the EOD tomorrow. The third and largest batch is being more cooperative and is sitting at about SG 1.060.

Just wondering what you all think. Thanks for your consideration.

 

[Rice_Guy]

* high temp increases nutrient demand and increases the risk of off flavors / yeast stress. I have seen SO2 production when at 35C.
* high temp is said to be responsible for blowing off fruity aromatics.
* the yeast are hearty buggers they will do their job at faster rates up until death.
I have done 40C and it was 3 days for dryness.
* fusil alcohols, off flavors.

 

[Rocky]

* high temp increases nutrient demand and increases the risk of off flavors / yeast stress. I have seen SO2 production when at 35C.
* high temp is said to be responsible for blowing off fruity aromatics.
* the yeast are hearty buggers they will do their job at faster rates up until death.
I have done 40C and it was 3 days for dryness.
* fusil alcohols, off flavors.

Wow, you're just full of good news!

I did not get that high, maybe hit 25 degrees C.

 

[winemaker81]

With overnight starters I get a faster ferment.

But, upon reflection, do I? An overnight starter gives the yeast a larger critical mass, so it can dominate the must quicker. A large part of the reproduction is done in an environment that is more to the yeast's liking.

Without a starter, it typically takes a day to notice fermentation, and another day (or two) for it to get vigorous. So what seems like a longer ferment may actually more a longer soak.

I've learned to like a colder ferment, as I do get more aroma. Reds can be too fruity for my liking, but barrel aging dampens that.

Last fall I left the reds in the fermenter for 2 weeks, so I had a short EM. Great for color and tannin, although I use Color Pro so color and tannin are good, anyway.

I'm just spitting out facts/ideas. I haven't conducted qualitative tests to determine if one method is actually better than another.

 

[sour_grapes]

On the plus side, a hotter fermentation is purported to extract more goodness from the skins.

 

[Tripled92]

With overnight starters I get a faster ferment.

But, upon reflection, do I? An overnight starter gives the yeast a larger critical mass, so it can dominate the must quicker. A large part of the reproduction is done in an environment that is more to the yeast's liking.

Without a starter, it typically takes a day to notice fermentation, and another day (or two) for it to get vigorous. So what seems like a longer ferment may actually more a longer soak.

I've learned to like a colder ferment, as I do get more aroma. Reds can be too fruity for my liking, but barrel aging dampens that.

Last fall I left the reds in the fermenter for 2 weeks, so I had a short EM. Great for color and tannin, although I use Color Pro so color and tannin are good, anyway.

I'm just spitting out facts/ideas. I haven't conducted qualitative tests to determine if one method is actually better than another.

I can second this. Don’t really have any qualitative tests either. Some blow through fermentation in 2-3 days others are 6-7 days. Some blow through in 3 days but take a day or 2 to start, and some start that night and blow through in 3 days. A bunch of factors including yeast, yeast starter, temperature, must, where the must was from, freshness of it, sugar content, yeast health and viability etc. We actually had a Cabernet that we did in 2023 and it blew through fermentation in 2 days. Throughout it was a goner, tasted it to this day probably still the best “at fermentation day” taste of any of our wines

 

[Rocky]

Just some additional information on my wines. There are 3 reds (Grancha/Carignan, Monastrell and Pinot Noir/Shiraz) and one white (Trebbiano/Riesling). I used a combination of D47 and EC1118 yeast in the reds and EC1118 only in the white. Nothing else was added with the exception of a gallon jug of Blackberry wine base and additional water to the Granacha/Carignan, which is a double batch, i.e. 2 kits of Granacha/Carignan.

 

[Tripled92]

Just some additional information on my wines. There are 3 reds (Grancha/Carignan, Monastrell and Pinot Noir/Shiraz) and one white (Trebbiano/Riesling). I used a combination of D47 and EC1118 yeast in the reds and EC1118 only in the white. Nothing else was added with the exception of a gallon jug of Blackberry wine base and additional water to the Granacha/Carignan, which is a double batch, i.e. 2 kits of Granacha/Carignan.

Just a suggestion, if you plan on using a yeast starter, yeast nutrient and have decent temperature, i don’t think you need to use EC1118 to help finish out fermentation. If anything, if its 6 gallons, you can use 2 5g packets of d47 if you are worried about fermentation. The yeast that isn’t used will just fall to the bottom of the bucket.

 

[Rocky]

Just a suggestion, if you plan on using a yeast starter, yeast nutrient and have decent temperature, i don’t think you need to use EC1118 to help finish out fermentation. If anything, if its 6 gallons, you can use 2 5g packets of d47 if you are worried about fermentation. The yeast that isn’t used will just fall to the bottom of the bucket.

I agree with your assessment. However, in this case, the kits were from 2021 and 2022 so I used the EC1118, "Turbo Yeast," as insurance.

 

[winemaker81]

I agree with your assessment. However, in this case, the kits were from 2021 and 2022 so I used the EC1118, "Turbo Yeast," as insurance.

The age of the kits is not a problem in your situation. If the concentrate is good, it's yeast food. If it's not good, well, it might be yeast food anyway, but you'd not want to drink the result.

Your wines are fermenting, so all is good. However, for future reference, make a starter with the preferred yeast. If fermentation doesn't take off after 24 hours from inoculation, then add the EC-1118.

 

[Tripled92]

I agree with your assessment. However, in this case, the kits were from 2021 and 2022 so I used the EC1118, "Turbo Yeast," as insurance.

Ohh makes sense! How is the wine going now?

 

[BPL]

Many folks brag about how fast their wines ferment and complain about being slow to start up. It's all wine in the glass at the end of the day.

What you are asking about (fast or slow ferment) gets pretty technical in the fact that the temperature of the ferment affects the physical molecules in the must, (aka, blowing off aromatics, off flavors, etc). It's the wine maker's choice to determine the extent of what is in the glass by methods of fermenting. In this case allowing a fast ferment, a cool ferment, or controlling what and how the yeast performs is >this choice<.

Yes, I have tested fast and slow ferments, measured the effluent from the fermentation (gas/CO2), observed resulting color, exothermic heat, and ultimately tastes. To put into perspective previous comments about fusels, color, "goodness from the skins", etc., I have attempted to condense roughly 10,000+ words into a single graphic. The bell curve represents the rise and fall of the exothermic profile of yeast during fermentation. The "mean" is the exact center of the yeast temperature specifications. FYI, Yeast activity follows the same profile, and 1/3 sugar depletion occurs at the peak of the bell curve.

The short story is pick a starting must temperature within the yeast specifications and apply it on the curve PROPORTIONALLY. The variability of the must temperature during fermentation is the retention or give away of the characteristics on either side of the starting point percentage wise. Conversely, locking in a temperature using controls or allowing a slight movement in the set point holds the yeast to a specific (and desired) flavor profile.

The choice is in your hands.

Barry

 

[Rice_Guy]

I agree with your assessment. However, in this case, the kits were from 2021 and 2022 so I used the EC1118, "Turbo Yeast," as insurance.

The sugar in a juice concentrate has infinite shelf life, basically if nothing has grown all the sugar is there.
The mineral and yeast nitrogen has infinite shelf life, basically if nothing has grown all the mineral & YAN is there.
Flavor and color will change with time. This is the key on picking a shelf life time period. Best storage is cool below 68F. Much of the change in flavor versus fresh happens in the vacuum evaporation factory processes.
Yeast in the kit will degrade with time. Best storage is cool below 68F.
Sorbate will degrade with time. Best storage is dry with low humidity. (And with a desiccant)

 

[Rocky]

Thanks, Madison. My cellar is currently at 65 degrees F and even in the Summer months only gets up to about 68. Regarding the juice in the kits, I did a very unscientific "smell" test and they all seemed fine. The exception was the Trebbiano-Riesling, which had significantly browned over the years. I went ahead with it anyway (In for a Penny, in for a Pound). It is lightening slightly and may be okay. If not, I merely wasted a packet of yeast and some distilled water. The price of the kit was a "sunk cost." I could always make a white vinegar!