Difficulty with non-culture PH drop

User avatar
StefanS
Passionate
Passionate
Posts: 353
Joined: Sun Feb 15, 2015 00:12
Location: Mass

Re: Difficulty with non-culture PH drop

Post by StefanS » Thu Aug 27, 2020 14:38

Where Lactic Acid Bacteria is involved in described above process? or any bacteria?
redzed wrote:
Wed Aug 26, 2020 16:52
After the slaughter the bacteria metabolizes available glycogen taking the pH from 7 to 6 or less. By adding sugar we feed the remaining lactic bacteria and get a further drop.
or I misunderstood your statement?
User avatar
redzed
Moderator
Moderator
Posts: 3373
Joined: Fri Apr 20, 2012 06:29
Location: Vancouver Island

Re: Difficulty with non-culture PH drop

Post by redzed » Thu Aug 27, 2020 15:56

First quotation:
Because there is no oxygen to complete the breakdown to carbon dioxide and water, and under the conditions found in the muscle at this time, the pyruvic acid is reduced to lactic acid. There is no blood circulation to remove the lactic acid, which therefore accumulates, and the muscle tissue acidifies. The pH drops from about 7.2 to 5.5 in a typical muscle.

Second quotation:
Formation of lactic acid during post-mortem glycolysis is responsible for the decline in pH value within the meat after slaughtering. The pH value of
meat at the point of slaughter varies depending on the type of animal but is generally between 6.8 and 7.2. After slaughter, the pH normally drops to
around 5.3 – 5.4,


And from The Encyclopedia of Meat Science, Vol. 1, p.262
pH Changes from Muscle to Meat
During the early postmortem changes in muscles of slaughtered
animals, the pH declines from approximately 7.0 in the
muscle of a live animal to 5.3–5.8 as its final value, termed as
ultimate pH (pHu). The reason for the pH decline is the formation
of approximately 0.1 mol l−1 lactic acid from glycogen
in the anaerobic glycogenolytic pathway.


The above authorities confirm what I wrote, and that is that lactic acid is produced naturally in the carcass after the slaughter and is responsible for the acidification.
User avatar
Bob K
Moderator
Moderator
Posts: 2106
Joined: Sun Jun 02, 2013 15:16
Location: Northwest Ct

Re: Difficulty with non-culture PH drop

Post by Bob K » Thu Aug 27, 2020 16:20

redzed wrote:
Wed Aug 26, 2020 16:52
Lactic bacteria occurs naturally in the carcass. After the slaughter the bacteria metabolizes available glycogen taking the pH from 7 to 6 or less. By adding sugar we feed the remaining lactic bacteria and get a further drop
redzed wrote:
Thu Aug 27, 2020 15:56
Because there is no oxygen to complete the breakdown to carbon dioxide and water, and under the conditions found in the muscle at this time, the pyruvic acid is reduced to lactic acid. There is no blood circulation to remove the lactic acid, which therefore accumulates, and the muscle tissue acidifies.
Isn't this two different ways of producing Lactic acid
LOUSANTELLO
Forum Enthusiast
Forum Enthusiast
Posts: 567
Joined: Fri Dec 18, 2015 23:35
Location: Chicago

Re: Difficulty with non-culture PH drop

Post by LOUSANTELLO » Thu Aug 27, 2020 16:25

But back to my question. Even adding sugar/dextrose to further drop the ph isnt happening without a starter culture to kickstart it, even if I hung it for the maximum 120 ferment hours. Im lucky if it drops 0.1 on a ph meter with 0.3-0.5% dextrose
User avatar
redzed
Moderator
Moderator
Posts: 3373
Joined: Fri Apr 20, 2012 06:29
Location: Vancouver Island

Re: Difficulty with non-culture PH drop

Post by redzed » Thu Aug 27, 2020 16:31

It was not my intention in the answer I provided to Eric to describe the chemical chain in the production of lactic acid in the carcass. I stated that it occurs naturally during post mortem. There is nothing in my answer about the production of lactic acid.
User avatar
redzed
Moderator
Moderator
Posts: 3373
Joined: Fri Apr 20, 2012 06:29
Location: Vancouver Island

Re: Difficulty with non-culture PH drop

Post by redzed » Thu Aug 27, 2020 16:33

LOUSANTELLO wrote:
Thu Aug 27, 2020 16:25
But back to my question. Even adding sugar/dextrose to further drop the ph isnt happening without a starter culture to kickstart it, even if I hung it for the maximum 120 ferment hours. Im lucky if it drops 0.1 on a ph meter with 0.3-0.5% dextrose
How many failed fermentations have you had when trying this?
LOUSANTELLO
Forum Enthusiast
Forum Enthusiast
Posts: 567
Joined: Fri Dec 18, 2015 23:35
Location: Chicago

Re: Difficulty with non-culture PH drop

Post by LOUSANTELLO » Thu Aug 27, 2020 16:36

3-4. I normally use a culture and only watched one drop without a culture
bluc
User
User
Posts: 83
Joined: Thu Jul 30, 2020 05:12

Re: Difficulty with non-culture PH drop

Post by bluc » Fri Aug 28, 2020 09:57

Just a random thought I am only just starting and have zero experience but just thought I would throw this out there.

Usually when bacteria/yeast(I do some home brewing) doesnt work its because of conditions. Are you trying to ferment the meat in same conditions you would use ferment it using a starter? In this case it may be your issue.? If you use anti bacteria agents like nitrate and salt you need to bomb it with bacteria to over come it(a starter culture) then you can ferment at a much lower temp then normal because the culture established a healthy colony straight away. Ferementing at lower temp without a starter may work but may take to long leaving you in danger zone longer.

if you dont use a culture maybe you need to leave the meat at higher temp[personally I would prob up temp 2-3c at a time until desired results are achieved and document so you know the sweet spot.] If you have not got somewhere maybe experiment at room temp. Giving the bacteria a fighting chance to overcome the salt and nitrate. maybe leave at higher temp for 2-3-4 hrs before putting in chamber see what it does. I thought of this after watching the lamb proscuitto video https://youtu.be/jl_ak-HEJwk
he leaves it at room temp for 8hrs before he puts it into chamber to develop flavour. Which I assume is done by building up a healthy bacteria colony at room temp before slowing the bacteria by putting it in a cooler enviroment to slow the effects of the bacteria and ultimately killing the colony off by removing the water leaving behind the yuminess..Lots of videos say room temp but not mant reference temp. Would make it muchmsimpilar if they did. After all fermenting without a starter is the same as fermenting with one just a lot less controlled and results can vqry wildly. Until you build a favourable indeginous colony.
Like beer if you do a mash then leave lid off it will ferment but will prob taste like crap. Or may be great

If you innoculate with a yeast that was harvested to be reliable flavour profile it will out perform local yeast because you add it at a rate high enough to achieve that.

Anyhoo just a thought feel free to tell me to bugger off if I am off the mark..
Post Reply