Author Topic: time v's target pH  (Read 2246 times)

Offline NimbinValley

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time v's target pH
« on: November 06, 2012, 11:18:28 PM »
Hi all.  I notice many people recommend to demould a (tomme) cheese and leave it 1 or 2 days before brining.  However, if the cheese has reached its target pH, say 5.2, in 12 hours should it go straight into the brine?  I guess I am thinking about reducing the chance of late blowing by ensuring all of the lactose has been consumed.  If the pH is already at 5.2 then most of the lactose would have been consumed then anyway - is this correct thinking?  Cheers.  NV

linuxboy

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Re: time v's target pH
« Reply #1 on: November 06, 2012, 11:52:31 PM »
Your drain pH combined with aging time has more to do with postacidification fault than terminal pH pre brine. That said, for a tomme style with high drain pH (6.3), it should naturally finish around 5.2-5.4 within 12 hours, after which it is best to brine. Not the end of the world if you don't, but with raw milk, it makes for a more consistent product to drop the pH quickly and salt quickly.

Clostridium will find other food if there's no available sugar. Will still blow. More of a pH issue and flora balance for the spores.

Offline NimbinValley

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Re: time v's target pH
« Reply #2 on: November 07, 2012, 12:21:01 AM »
The only time I have had post acidification issues is when I have used silage fed cow milk. 

Yesterday's make was quite difficult but I might describe it as others may find it interesting to see what I did and why I did what I did! 

I was making a cow milk asiago style cheese, meso/thermo mix with a few adjuncts.  Pasteurisation was to 65oC but I was unable to cool it down quickly and since the water jacket holds a lot of residual heat the milk likely went much higher and stayed there for about an hour.  As you would expect I had a very soft set and a very long healing time after I cut to ensure that I didn't lose everything.  As a result the pH was already bordering 6.35 by the time I got to stir.  I was worried about too much acid development so I added a wash step to remove as much lactose as I could.  I replaced 60L of whey with water in a 200L batch.  The curds firmed up quite well as I cooked up to 50oC.  I usually only go to 48 but I wanted to drive out more moisture.  The pH at whey-off was 6.09 in the whey, so likely around 6 in the curd.  Despite this it knitted together well (high temps help I guess) and 12 hours later the pH is 5.35. 

So now I will brine it and see how it goes...  Anyway, I think I solved the problem in the best way I knew how so it will just take a few months to see the results.  Any questions/comments would be appreciated as a learning exercise.  Thanks.  NV.

linuxboy

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Re: time v's target pH
« Reply #3 on: November 07, 2012, 01:34:20 AM »
Want to make sure we are we talking about the same thing... Excess acetic/other VA due to secondary fermentation? If so, this should be present mostly in aged cheese (>8 months) when there's pH tipping point mismatches between acid/buffering and affinage schedule (temp) combined with MFFB. Anything else is multiple fermentation paths due to unclean milk or sanitation issues or particular bacteria ecology quirk.

That's some quick thinking, seems like the make worked out OK in the end.

Offline NimbinValley

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Re: time v's target pH
« Reply #4 on: November 07, 2012, 03:04:28 AM »
Ok.  When I have had blown cheeses in the past they have been (apart from 1 case) from cow milk at times when cows have been fed silage.  Blowing started about week 4.  The one case with goat milk I put down to a contamination issue.  It also occurred about week 4 from memory.

linuxboy

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Re: time v's target pH
« Reply #5 on: November 07, 2012, 03:11:03 AM »
yeah, that's classic clostridium spores likely got sucked into the milk line.