Page 1 of 2

My pH is in the rise

PostPosted: Sat Mar 19, 2016 2:23 pm
by Jokat
So I made some salami with a fresh bactoferm starter culture and within 24 hours, I observed the pH drop to about 4.95, so I brought the humidity down to 60% and over the next 5 days the pH climbed up to 6.7.
What's going on?

Re: My pH is in the rise

PostPosted: Sat Mar 19, 2016 7:50 pm
by NCPaul
Welcome to the forum. :D How and with what are you checking the pH?

Re: My pH is in the rise

PostPosted: Sun Mar 20, 2016 12:24 am
by wheels
:D :D Welcome.
My question would be likewise.

A pH of 6.7 is outside of what I would call normal.

Phil

Re: My pH is in the rise

PostPosted: Sun Mar 20, 2016 7:13 pm
by BriCan
Jokat wrote:I brought the humidity down to 60% and over the next 5 days the pH climbed up to 6.7.
What's going on?


Humidity is way too low :(

Re: My pH is in the rise

PostPosted: Sun Mar 20, 2016 8:01 pm
by wheels
Robert, isn't 6.7 DFD territory?

Phil

Re: My pH is in the rise

PostPosted: Sun Mar 20, 2016 9:51 pm
by BriCan
wheels wrote:Robert, isn't 6.7 DFD territory?

Phil


ph of 6.7 is bad

what I was saying that dropping humidity down that far is bad --- all my notes/work stuff is on my laptop which is down right now so no access for at least a week

Fermentation always high -- 80% - 90% ... dropping down to no lower than 75%

Re: My pH is in the rise

PostPosted: Sun Mar 20, 2016 11:39 pm
by wheels
Thanks.

I guess that we need a reply from the OP before this can progress.

Phil

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 3:53 am
by Jokat
I tried to reply once but it hasn't shown up.
I used bt007 culture with bioprotectant.
I'm using a Hanna pH meter for meat. Yes, it's been calibrated.
Like I said, it came down in around 48 hours to 4.95pH bit then began to rise up and it 5.89 currently.
It's been 6 days now.

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 11:12 am
by NCPaul
Dark Firm and Dry (DFD) meat (Fig. 1)

This condition can be found in carcasses of cattle or sheep and sometimes pigs and turkeys soon after slaughter. The carcass meat is darker and drier than normal and has a much firmer texture. The muscle glycogen has been used up during the period of handling, transport and pre-slaughter and as a result, after slaughter, there is little lactic acid production, which results in DFD meat. This meat is of inferior quality as the less pronounced taste and the dark colour is less acceptable to the consumer and has a shorter shelf life due to the abnormally high pH-value of the meat (6.4-6.8). DFD meat means that the carcass was from an animal that was stressed, injured or diseased before being slaughtered.


I think this condition would be a factor at the beginning and that the pH would not have been able to drop below 5 after 24 hours. Are you checking the pH directly or making a slurry? Are you checking a salami or a bit of meat wrapped in cling wrap? You haven't mentioned your temperatures, what are they? How much dextrose is in your recipe? How is the appearance and smell of the salami? Sorry for all the questions.

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 12:59 pm
by wheels
NCPaul wrote:I think this condition would be a factor at the beginning and that the pH would not have been able to drop below 5 after 24 hours.


Good point. :D

Phil

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 3:19 pm
by Jokat
The pH meter has a meat probe and I stick it right into a sausage. I rechecked the calibration a couple times and it didn't change.
I didn't use any dextrose because the basic salami recipe from "Salumi" doesn't call for dextrose. I used some toasted black pepper and fennel.
Temps have been all over the place but between 65-80F, mostly closer to 80F. I kept my chamber at 80%rh and 80*F for the first three days. That,s when I saw the pH drop down to 4.95.

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 6:15 pm
by NCPaul
This temperature range is a problem. In the fermentation phase of making salami the temperature can be 80 F and high humidity (90 % RH) to multiply the bacteria and to cause them to acidify the sausage. The acid is most conveniently made from dextrose in the recipe but can be produced from natural sugars and carbohydrates in the meat. This process should take no longer than two days. The drying phase lowers the temperature to 65-55 (even lower I like) and the humidity is dropped to 80-85 % RH. If your pH is increasing at your higher than recommended temperatures and lower than recommended humidity, it may be because of spoilage bacteria or enzymatic changes in the meat.

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 9:44 pm
by Jokat
OK, so do you have any recommendations Paul?
At this point I've decided to toss the batch. Sucks, buy I would also like to learn from it so this isn't a total loss.

Re: My pH is in the rise

PostPosted: Mon Mar 21, 2016 9:51 pm
by Jokat
....I'm basically following the times and temps in the Salumi book.
If I'm not mistaken, it recommends 80RH and 80*F until pH reaches 4.9 and then reduce temp to 60F and RH to 65.
Does that sound right or should I keep RH of 80 during drying?

Re: My pH is in the rise

PostPosted: Tue Mar 22, 2016 2:07 am
by NCPaul
I'll try to reply tomorrow.