I will get the devastating part of this out of the way first. Due to, what I believe, is temperature shock I have lost two gallons of sake.
The Set Up: I did most of the secondary fermentation, of a six gallon batch, in a five gallon carboy. I racked that into one gallon and three liter glass wine bottles, and allowed these bottles to sit on the counter overnight to warm to room temperature. The plan was to pasteurize and age the sake in these bottles.
The Procedure: Filled two stock pots about half full with cold tap water and placed on burner with the flame set as low as I could manage it. I then paced the bottle in the pot with the cap off, and inserted the probe of a thermometer with the temperature alarm set at 140F.
The first bottle broke at about the five minute mark. I turned off the heat to both pots and removed the unbroken bottle from its pot. After several minutes of many “gosh darns” and dagnabits”, I believed that the breakage occurred due to the direct contact of the glass bottle with the metal pot. To insulate the glass from the metal I folded two dish towels four times and placed them on the bottom of the remaining pot, placed the second bottle on top of the towels. This raised the bottle about one inch off the bottom of the pot. I then repeated the above heating procedure. The second bottle also broke at about the five minute mark.
1)The temperature of the sake was lower than I expected it to be. About 63-65F.
2) The temperature of the water in the pots was still cold to the touch. It had not warmed to any perceivable degree.
3) Both bottles broke in the same time frame, and in exactly the same manner.
1) It is possible that there were micro fissures in the second bottle caused by the same stresses that caused the first bottle to break. However it showed no visible cracks or was leaking.
2)Given that the sake temperature was 63-65F, and the cold tap water temperature was still at its normal temperature (approximately 75F), is it possible the difference in the temperatures between the bottle and the tap water was enough to cause temperature shock?
I would appreciate any advice, experience pointers, or speculation the forum cares to give.
Thanks in advance,
P.S. Now I have to make more sake sooner than I had planned. Well shucky darns!