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Question on fermenting with UMAi bags

Posted: Mon Jan 19, 2015 22:52
by Lance Link
After some research and reading of successes people have been having using this method I thought I would give them a try. I am making a soppressata with T-SPX for fermentation. The instructions say to hang at room temp for 48-72 hours, but there is no mention of humidity. I understand that when using a traditional casing temp and humidity need to be exact for the bactoferm to work properly. My question is, does it not matter when using these bags? To keep a constant temp, I have them in my bread proofer at a constant 70 degrees. The Rh without a water pan is a constant 83.6%. Is this okay? Any opinions would be appreciated.

Posted: Mon Jan 19, 2015 23:53
by Devo
I always follow the manufacture instructions for the culture your using. Just because its a UMAi bag dose not mean we should stray from the norm. Follow the manufactures instructions and test your Ph with a meter of Ph tape. You can not just go by time Temp & R/H and hope that you have the right PH like some on the UMAi site seem to think. There are to many variables to hope you got it right just from that.

Posted: Tue Jan 20, 2015 07:28
by redzed
Lance that is a very good question and one that I have been pondering about myself. Unfortunately there are no technical bulletins with instructions on using the Tublin 10 material, which is what Umai is selling. This is all that is available:
http://www.tub-ex.com/Food-grades.24.aspx?recordid24=14

The recipes on the Umai site do not provide enough insight as to what is really going on with the meat, there is no discussion or instructions on how to use starter cultures and how they actually work. When we make salami using conventional methods, the fermentation stage is the most critical of the whole process and maintaining a high humidity (90-95%) during this stage is very important. The high humidity should be maintained until the pH drops to 5.2. But since the Tublin material is only permeable from the inside, it may make very little difference what the RH in your curing chamber is. The bacteria will need to rely on the water activity (Aw) in the meat to do its job and lower the pH.

And as Devo pointed out, you need to know whether the pH has dropped and if you are using T-SPX you don't want it to drop below 5.2, and if it goes lower that 5 you will have a sour tasting salami. There are a number of factors that affect how much and how fast you will have a pH drop. If you ferment at a slightly higher temp or add a little more sugar sugar, your pH will drop faster. On the other hand if you don't distribute the starter culture throughly in the farce, or don't add enough, or the culture is not that fresh, it will probably take longer to get to that 5.2 reading. So you do need to check the pH, rather than blindly following the recipe that tells you to ferment for 48 hours.

Posted: Tue Jan 20, 2015 13:58
by Lance Link
Thanks for the replies. I was thinking the same that the bags are designed to let moisture out and not in so the rh outside the casing shouldn't be a factor. I will have to test the ph.

Posted: Tue Jan 20, 2015 15:06
by Devo
I have made several types of salami using these bags and the Ph drop was the same as if I was using natural casings. The nice part about these bags is now with the tie strap you can open them up and test your product and reseal. There are a lot of old time salami makers who give these bags a bad rep, probably because people take short cuts from the norm.

Posted: Tue Jan 20, 2015 15:59
by Shuswap
I feel the pressure of adopting pH measures when using Umai bags for fermented products in spite of what Umai says about it not being necessary.
In addition to what has been said on this forum, I have been doing other reading on the subject. This morning I came across this article by Eutech Instruments (there are several of interest) which describes how the pH value of meat provides evidence of how long the meat will keep and indicate technical processing characteristics from the point of slaughter to final product. An interesting read: http://www.eutechinst.com/tips/general/17.pdf

Posted: Tue Jan 20, 2015 16:49
by Devo
Good read and thanks Shuswap. I read an article 8 or 9 months ago about how people die from the wrong Ph in foods. For the life of me I can't find it any more. Anybody have information on that? The proper Ph in canned foods is important is it not?

Posted: Tue Jan 20, 2015 23:23
by Lance Link
I have ordered a ph tester, albeit a little after the fact. I can still test when it arrives I'm guessing just to see where it's at. Also assuming my soil ph meter won't do the job.

Posted: Wed Jan 21, 2015 00:01
by Bob K
Actually Lance if you are confident that it is accurate you can make a slurry of a meat sample and unionized or distilled water and check the Ph with your soil meter

http://www.milwaukeeinstruments.com/phinmeat/

Posted: Wed Jan 21, 2015 01:25
by Shuswap
There is a $60 difference in price between amazon. com and amazon.ca for the Milwaukee 102 meter. With today's excchange rate there should only be a $21 difference. Looks like cross-border shopping to me. :shock:

Posted: Wed Jan 21, 2015 14:13
by Lance Link
Bob K wrote:Actually Lance if you are confident that it is accurate you can make a slurry of a meat sample and unionized or distilled water and check the Ph with your soil meter

http://www.milwaukeeinstruments.com/phinmeat/
I couldn't attest as to it's accuracy as there isn't an type of calibration tool with it.