Hi, I just wanted to give my experiences I had tonight with my first try at pasteurizing. I started by following the guideline of 160-175 degree bath after soaking in 110-120 prior. The bottles weren't in the hot water bath for more than 3 minutes when I lost 2 of them. the second set of bottles I put in the hot water bath I didn't let get over 160 degrees. I only lost 1 bottle on that batch. I then decided to do a quick search online for what temperature kills yeast best and I found that 138-140 was agreed upon most. so for the last few sets of bottles I did not let the temperature get over 150 and I made sure that it went over 140. Other than my 3 casualties everything else went well.
Thanks for sharing. Sounds like you had some fun
.... a few comments:
- The real test whether your method works is whether you actually killed the yeast ... so I would celebrate your method only after another month or so and I keep my fingers crossed that it will work!
- While you are right that the yeast dies at around 140, the whole trick in these recipes is to make sure that the complete bottle and its content gets warmer than 140. That is not the same than saying that the water in the pot is over 140. The often cited Cornell research
paper on cider pasteurization is based on two test series:
In series 1) they hot-fill cider and thus measure the actual cider temperature. In these tests they showed that cider temperatures between 140 and 150 were enough to stop fermentation
In series 2) they put bottles of cider into a hot water bath. This series they did at 165F water temperature not at 140-150F. I don't know why they did not try it at lower temperature (so it does not necessarily mean it does not work) but I did find it interesting that they did not even try and assumed that heat transfer from the water into the bottle is not perfect for the time-spans we use (i.e. minutes). The would be my gut feel as well since the amount of heat transferred between water and bottle is proportional to the difference in temperature. Thus, I would expect the bottles to be slower to reach the last few degrees towards equilibrium with the surrounding water and therefore getting to the same temperature than the water.
- My experience has shown that temperature is more critical (in terms of having bottles explode) than most other parameters such as duration or amount of air in the bottle. Especially with my more critical brews (such as my Malzbier) I am very careful to keep the temperature between 160 and 170 and never exceed 170.
- However, even in that range, I have bottles explode if the carbonation is high so I think I agree with Daze that your carb level might have been on the high side. One tip from Daze (verified by me) is to release pressure from the bottle before pasteurization (and or course re-cap) - it will not kill carbonisation but greatly extend the safe range of pasteurization conditions.
BelMamba