Author Topic: First cheese attempt... mould contamination?  (Read 2827 times)

ScottC

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First cheese attempt... mould contamination?
« on: February 06, 2011, 07:33:04 AM »
Hi Everyone,

My wife and I decided to attempt cheese making. We made a cheddar and two Camembert style cheeses. The cheddar is unknown at the moment because it's waxed and waiting for a few more months (or weeks, depending on my patience).

The (potential) problem is that the Camemberts that look and taste OK, with the exception of small non-white mould colonies growing under the surface P. candidum. I've included our method, in case it's important. If not, skip to the last paragraph :-)

The cheeses were made by the following process:

  • 200mL UHT milk inoculated with a new, commercially purchased dry starter and kept warm overnight
  • 4L pasteurised non-homogenised milk brought to 42ºC and inoculated with 70mL overnight starter culture.
  • Inoculated with small amount of new, commercially purchased, dry P. candidum spores
  • Added 0.8mL rennet and maintained temperature for 40 minutes.
  • Cut the curd to 2cm cubes and rested for 30 mins
  • Turned curd and rested for a further 30mins
  • Turned curds and rested for 30 mins
  • Drained off the whey
  • From this point on, the cheese was at room temperature (about 25ºC)
  • Filled baskets and drained for 5 mins
  • Turned and drained for 1 hour
  • Turned and drained for 2 hours
  • Turned and drained for 2 hours
  • Turned and drained for 3 hours
  • Turned and drained overnight
  • Soaked in 25% w/w brine for 45 minutes, turning at 20 minutes
  • Removed the cheeses to a draining rack inside a 25cmx18cmx10cm (LxWxH) plastic container with the lid resting on tops, sideways (but cheeses covered)
  • Dried in the plastic container for 12 hours
  • Added 0.5cm of water below the drying rack in the above container and closed the lid.
  • Moved the plastic container to storage at 11ºC (fluctuates between 9-12ºC)
  • Left for 2 weeks, turning occasionally, then wrapped in microperforated plastic lined foil wrappers.
  • Left wrapped for a further week.
The P. candidum developed without any problems... nice even coverage over the whole cheese. It was first noticeable at day 8 after moving them to storage.






They are now 21 days old and we unwrapped and cut one to see how they were progressing. The cheese we cut looked fine, and smelled clean and fresh. The paste is still quite firm.







To cut a long story short, the main concern we have is the presence of a few non-white moulds. There would probably be maybe 5 or so on one of the large surfaces of the cheese. They are only growing at the interface of the white mould rind and the curd. I.e. under the white rind, but against the curd - they're not visible at all on the rind surface (which looks uniformly white) and not anywhere inside paste. Perhaps they're spores that have landed on the surface of the cheese during drying, or maybe they're not able to grow in the centre of the cheese (maybe due to lack of oxygen or requirement for salt). They're quite small at only around 2mm diameter and quite thin, only just visible in a cross section of the cheese:



If I carefully slice off the ride to reveal the paste surface, the colonies are visible. I can see two colours - a dark pinky red and a dark green/grey. I have read that the P. candidum can appear pink when it's too humid, but I assume that this would normally be present on the cheese surface, not under the white rind. I wouldn't have thought that it'd appear as a discrete dark red/pink colony like this... but I've never seen it before, so I don't really know.





So I guess what I'd like to know is

1) Is this a common problem? I've seen plenty of hard cheeses with natural rinds that have all kinds of funky moulds growing on them, but not white softies like this.
2) Is it simply a matter of better disinfection of equipment during the process to keep these things at bay, or am I doing something else wrong?
3) Any other feedback on the mould, the cheese, the method, or anything else would be appreciated :-)

Cheers,

Scott.
« Last Edit: February 06, 2011, 08:45:37 AM by ScottC »

FRANCOIS

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Re: First cheese attempt... mould contamination?
« Reply #1 on: February 06, 2011, 07:35:21 PM »
It's environmental contamination, probably from your fridge.  Not a big deal and it will sort itself out of you start making lots of this cheese.  The fridge will reach an equlibrium and become satured with good mould spores.

ScottC

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Re: First cheese attempt... mould contamination?
« Reply #2 on: February 07, 2011, 03:32:21 AM »
Thanks for the comment.

I'd assumed they were stray moulds from the environment, but I think they must have come from before the fridge, since they were sealed in a plastic container at that point. I guess I'll have to be more careful during drying. How/where do people dry their cheeses to avoid this?

Cheers,

Scott.

FRANCOIS

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Re: First cheese attempt... mould contamination?
« Reply #3 on: February 07, 2011, 08:17:09 PM »
Take the recommended dosing rate for the white mould and quaduple it.  Then quadruple dose your brine.  Nothing else will grow, trust me.

ScottC

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Re: First cheese attempt... mould contamination?
« Reply #4 on: March 04, 2011, 04:05:26 AM »
Thanks for the advice... but we can't quadruple dose our salt since we're putting it in brine that certainly won't take 3x more salt than we're using now... unless you just mean soak for 4x longer (or use dry salt on the surface instead?).

linuxboy

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Re: First cheese attempt... mould contamination?
« Reply #5 on: March 04, 2011, 04:13:46 AM »
He means increase the amount of candidum. That way, if you totally saturate both the milk and brine, the candidum will grow so quickly and so thickly that it will outcompete everything else.

ScottC

  • Guest
Re: First cheese attempt... mould contamination?
« Reply #6 on: March 05, 2011, 07:01:19 AM »
Oh Ok I understand. I don't think the P. candidum growth was a problem though... we didn't see any other moulds until well after the P. candidum was thick! In fact, we didn't even know they were there until we cut them open.

jo1973

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Re: First cheese attempt... mould contamination?
« Reply #7 on: March 30, 2011, 12:14:44 AM »
hi, i am a beginner cheesemaker, and have just recently made my first batch of camembert which was growing a lovely soft white mould on it, then started growing some blue mould spots on it, so i cut them off and now the cheese is exposed and i don't know if i have cut too much off or not.  Will the white mould grow back or not.  It has nearly been 10 days of ripening and still the cheese is not covered totally.  Any suggestions?  Thanks.

9mmruger

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Re: First cheese attempt... mould contamination?
« Reply #8 on: March 30, 2011, 12:24:14 PM »
Wash your hands real well, then pat the cheese and smear the existing mold into the open areas.  You could also sprinkle a few grains of salt on the open areas as well.  It should recover nicely.

jo1973

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Re: First cheese attempt... mould contamination?
« Reply #9 on: March 31, 2011, 05:43:04 AM »
Thanks for the advice, I am sure with practice I will get better at monitering my cheeses.  Will give your suggestion a try.