Fermentation?

We have 3 one-quarter stainless steel kegs in our fermentation chamber that currently holds our Chenin blanc harvest. We harvested our first one-quarter keg on September 17th, allowed it to cold settle the gross soluble solids and kicked off our fermentation on September 25th. We observed the slow start of fermentation 44 hours later. But, like any anxious parent we were holding our breaths until we could see this event.
For our second harvest that occurred on September 26, we followed our typical protocol of settling the gross soluble solids and added our yeast on October 2nd. We waited at least 48 hours to see if we could observe any signs of fermentation on those two kegs and nothing was happening. I looked online to see if I could learn anything about why fermentations can fail and I found an excellent enumeration a la David Letterman called Top 10 Reasons For Fermentation Failure at the E.C. Home Winemaking & Beer Making Supplies Website.

• Fermentation temperature too hot or too cold
• Adding too much sugar at the beginning of fermentation
• Improper yeast starting method
• Sealing up the fermenter after adding sulfites
• Using a wine airlock at the beginning of fermentation
• Lack of nutrients
• Fermentation has already completed
• Yeast has reached its limit
• Using distilled water
• Yeast is too old

Patience can be a virtue, but after 72 hours elapsed, we decided to look into the kegs. We could see foaming on the top of one of the kegs and the beginning of foaming on the other. We took a Brix reading and tasted juice from both of the kegs and on the one with foaming, we could definitely taste a fizziness in the juice, good indications of fermentation. My husband decided to test the fermentation locks and when he switched the fermentation lock from the keg that was fermenting to one of the kegs where the fermentation lock was not giving any indication of fermentation this is what we saw:

So to the list of "Top Ten Reasons For Fermentation Failure" add:

• Defective fermentation locks

Here is a very short video of a fermentation lock in action: