Author Topic: Gas Exchange in Aging Cheese  (Read 406 times)

Offline Milk Maid

  • Medium Cheese
  • ***
  • Location: San Francsico, CA
  • Posts: 33
  • Cheeses: 1
  • Default personal text
Gas Exchange in Aging Cheese
« on: February 07, 2013, 01:11:40 PM »
Would someone explain to me the gas exchanges occuring with aging cheese? I know the cheeses need O2. Do they 'exhale' co2 like us humans?

Thanks-


Guests, join the CheeseForum.org community to remove this ad.


Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 198
  • www.wacheese.com
    • Washington Cheese Guild
Re: Gas Exchange in Aging Cheese
« Reply #1 on: February 07, 2013, 02:16:44 PM »
Quote
I know the cheeses need O2.
Why do you think they need O2? And which cheeses?
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.

Offline Milk Maid

  • Medium Cheese
  • ***
  • Location: San Francsico, CA
  • Posts: 33
  • Cheeses: 1
  • Default personal text
Re: Gas Exchange in Aging Cheese
« Reply #2 on: February 08, 2013, 01:52:52 PM »
I assumed (hah!) that the reason cheeses needed air was because they needed O2. But maybe that's wrong. There's some gas they're getting when I open the lids to the aging boxes. As far as cheese variety, I was thinking in general. But if there is variation between cheeses, how about a bloomy rind.

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 198
  • www.wacheese.com
    • Washington Cheese Guild
Re: Gas Exchange in Aging Cheese
« Reply #3 on: February 08, 2013, 07:52:52 PM »
Well it's not like you're wrong or right, I was just curious, trying to understand the question better.

Gas production varies with the cheese. For example, are we talking about PAB in swissies? That's predominantly CO2. For bloomies, that's NH3. Maybe a better way is to describe the processes that produce gas and where they occur, and who is responsible. And what processes need either air exchange or oxygen.

The first major gas exchange happens with NSLAB consumption of lactate.
- NSLAB uses O2 to help with lactate metabolysis, and a byproduct is CO2. The rate and degree of CO2 production is directly limited by O2 availability.
- For example, in large cheddar blocks in plastic bags, there's little to no O2 coming in, limiting the CO2 production.
- This process is largely inside, not on the rind. Requires O2 to penetrate.

Second gas exchange happens on the rind
- Species such as geo and p candidum oxidatively consume lactose. And a byproduct is both CO2 and O2.
- Happens rather quickly, requires oxygen
- Also, protein breakdown happens on the rind, and this produces NH3.

Third gas exchange type is more of a production by heterofermentive bacteria such as Leuconostoc and PAB
- for leuconostoc and others, citrate consumption produces CO2.
- For PAB, same thing, CO2 production, but metabolic pathway is different.

Other minor activities happen, like protein breakdown overall producing NH3, various LAB metabolisms producing small amounts of CO2, etc. Usually not consequential.

In practical terms, cheese needs air for the oxygen to grow surface mold for bloomies, air movement to evacuate NH3 that's produced, and oxygen for NSLABs.
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.

Offline Milk Maid

  • Medium Cheese
  • ***
  • Location: San Francsico, CA
  • Posts: 33
  • Cheeses: 1
  • Default personal text
Re: Gas Exchange in Aging Cheese
« Reply #4 on: February 12, 2013, 05:12:34 PM »
Thank you LB  :)


Guests, join the CheeseForum.org community to remove this ad.


Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 198
  • www.wacheese.com
    • Washington Cheese Guild
Re: Gas Exchange in Aging Cheese
« Reply #5 on: February 12, 2013, 05:27:30 PM »
<3 Any time :)
Taking an extended leave (until 2015) from the forums to build out my farm and dairy. Please e-mail or PM if you need anything.

Offline bbracken677

  • Old Cheese
  • *****
  • Location: Dallas, Tx
  • Posts: 1,166
  • Cheeses: 16
  • I love me some cheese!
Re: Gas Exchange in Aging Cheese
« Reply #6 on: February 12, 2013, 05:42:10 PM »
where they occur, and who is responsible.

All I can say is...he who smelt it, dealt it! 

(wasn't me!)


 >:D