Joe, Bill is right about the SO2, although Gene is right about pH dependency. I just think Bill is closer to the SO2 load you put in than Gene is. The normal dose for a 5-gallon carboy is 1/4 teaspoon of K-meta, and you quadrupled that for only 4 gallons.
My advice has always been to make a yeast starter. You will know very quickly if the yeast is viable because the yeast is confined to a small volume of liquid. If you dump it into a 4 or 5 gallon volume, you might waste two or three days before deciding the yeast is no good.
Generally, when making a starter, never put yeast in water warmer than
100 degrees F. Most wine yeast die at 104 degrees, although some can hold out to 110. Don't play with the health of your yeast. They make the wine. You just facilitate the experience and clean up after them. But each yeast strain is different.
You said you were using Lalvin ICV-D254. This yeast has an optimum fermentation range of 64-82 degrees F., with a low tolerance of 53 and a high of 89. Within those limits, it should ferment. In the optimum range, it should ferment very well. However, it is a low-foaming slow fermenter, which is why it delivers a rich mouthfeel.
As for temperature shock, I am fairly certain the yeast do not experience die-off unless they exceed the limits for the strain (for this one, as described above). Yeast that have undergone temperature shock are usually just stunned and go into a sort of hibernation that can last from several hours to several days. ICV-D254 is an ADY (active dry yeast), not a freeze-dried yeast as many people think. It becomes active when rehydrated. I don't think it can go into shock until then (I refrigerate mine at 40 degrees F.), so if you added the dry yeast to a cold must it should have activated if within the temperature limits mentioned above.
I hope this helps. If I misstated anything, Lum, Tom S., Ray, Ed, Joe, and others will correct me so stay tuned.
Jack Keller, The Winemaking Home Page
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