Author Topic: Bitterness from too much culture  (Read 4040 times)

JeffHamm

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Bitterness from too much culture
« on: September 11, 2011, 07:26:41 PM »
Hi,

I've read on the boards that too much rennet can cause bitterness, but that if you age the cheese that this will go away.  I've also read that longer aging of cheeses made with vegetable rennets (or is it microbial rennets) will become bitter; so I'm assuming that the "aging to remove bitterness" is either restricted to calf rennet, or that the bitterness arises for different underlying reasons in the two cases.

Ok, what I'm more curious about is the bitterness that arises from too much starter culture.  Does this develope with age?  I've had one cheese that seemed to be slightly bitter, mostly on the finish.  It's a cheese I've made a few ttimes, and it's never been bitter before.  However, I aged this much longer than the others (took it over 100 days; which isn't huge long or anything), and I think I had used more culture than the other makes.  I used to use 1 or 2 ice cubes of cultured Flora Danica, but I started useing 4 (about 1.2% volume of a 10L batch). 

I've checked my notes, and see that I have a couple other cheeses made with 4 ice cubes of starter.  These ones I've been aging for a long time (at about 6 - 8 months).  If 4 ice cubes turns out to be too much culture, are these likely to be exceptionally bitter, as in unedible, or does bitterness due to over culturing peak, and then fade?  I guess I could wait a few more months to find out, but I'm worried now.

- Jeff


linuxboy

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Re: Bitterness from too much culture
« Reply #1 on: September 11, 2011, 07:44:17 PM »
It's not that straightforward.

In all cases, bitterness is caused by the creation of small protein chains (called peptides). Those chains are brought about when a large chunk of a protein is cut. Enzymes do the cutting. Enzymes are site-specific with where on the larger protein strand they cleave it into peptides. After peptides, the chains are broken down even more into various flavor forming compounds and amino acids complexes.

Now, the amount of enzymes and the type of enzymes make a difference. If you have a large amount of residual rennet, for example, it will be more aggressive in its reaction rate. If you have a calf rennet, it will act differently than the "identical" FPC, and different than M miehei and similar derived enzymes. The culture selection makes a HUGE difference. The amount does, but in your case, it's not that relevant. 1.2% is perfectly acceptable.

Tomer1

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Re: Bitterness from too much culture
« Reply #2 on: September 11, 2011, 08:39:10 PM »
Im having a hard time grasping the reason for difference in culture amount (represented as % bulk culture) in different cheeses,
Is the variation between different type of cheeses adapeted to the make in order to hit the ph targets and not acidify too slowly or too fast?


linuxboy

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Re: Bitterness from too much culture
« Reply #3 on: September 11, 2011, 08:43:38 PM »
Yes, it is to balance time with acidity. Sometimes, you don't want to wait for 4 hours before finishing the shift (mozz, cheddar). Sometimes, you want to wait 24 hours (lactic or semi-lactic).

Honestly, the variation is minor. Most of the time, it's a straight 1%.

Tomer1

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Re: Bitterness from too much culture
« Reply #4 on: September 11, 2011, 10:02:35 PM »
Thanks, its good to know.

JeffHamm

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Re: Bitterness from too much culture
« Reply #5 on: September 11, 2011, 10:36:47 PM »
Thanks for that.  Sounds like my culture amount should be ok, although I have backed down to 2 cubes and the cheese turns out just fine.  I'll be bitterly dissappointed if, after waiting a year or more, my mangengo and romano have to go in the bin.  Fingers crossed.

- Jeff

linuxboy

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Re: Bitterness from too much culture
« Reply #6 on: September 11, 2011, 10:54:39 PM »
Age them more if they are still bitter. It does go away. Vac pack and leave them be.

JeffHamm

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Re: Bitterness from too much culture
« Reply #7 on: September 12, 2011, 12:52:02 AM »
Ahhh, so it does eventually go away.  That's good to know.  I know darius mentioned that her cheeses seem to get bitter around 3 months or so, which is similar to my one that had a slight bitter finish.  I'll mention this to her as well.  It seems it builds up though, as neither of us have had any bitterness for younger cheeses.  I wonder what the time course is? ....

- Jeff

linuxboy

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Re: Bitterness from too much culture
« Reply #8 on: September 12, 2011, 01:15:37 AM »
It's not a given, but that tends to happen. If the enzyme soup mix is wrong, it may take a long time. Generally, if you have a high calcium, dry (35% MFFB or lower) cheese, the bitterness will go away with time. For more moist cheeses, or if your enzyme mix is not appropriate, the bitterness will likely remain. It's about rate of reaction (temp, ph, and water limited), and about types of enzymes and quantity (rennet, milk, and bacteria).

JeffHamm

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Re: Bitterness from too much culture
« Reply #9 on: September 12, 2011, 01:54:17 AM »
Gotcha.  I realise that there are always many things to consider.  I'm just happy to know that it's not a given that I've got a cave full of bitter pills to swallow.  Both darius and I were talking about caerphilly, and it is a cheese that is typically eaten quite young.  So it could be that therein lies the problem. 

- Jeff

Offline Hande

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Re: Bitterness from too much culture
« Reply #10 on: September 12, 2011, 05:32:19 AM »
Jeff, you can try measure of your icecube volume too, if you are not yet already do that.
I measure 2 different type trays and both was about 16 ml / icebube.
I take 100ml water and look how many cubes you can fill. To me it was 6 cubes.

Hande

JeffHamm

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Re: Bitterness from too much culture
« Reply #11 on: September 12, 2011, 08:21:39 PM »
Thanks Hande.  I measured my ice cubes once before, using a syringe, and they were close to 1 oz, so close to 30 ml (which is why I increased to 4 cubes, as that gets me around the 1% mark).  I should mesure them again and get a proper estimate.  I might just fill the ice cube tray, then weigh the cubes when done to get an average weight.  Since water converts 1g = 1 ml, that should get me a decent estimate. 

- Jeff

P.S. Hmmm, got the syringe out again, and I think my ice cubes are more like 20 ml (which is cloesr to your 16 ml cube size).  Must make and measure a tray and see what this comes to.
« Last Edit: September 13, 2011, 06:04:47 AM by JeffHamm »

JeffHamm

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Re: Bitterness from too much culture
« Reply #12 on: September 15, 2011, 06:24:05 AM »
So, I weighed the ice cubes and 16 of them weighed 360g, so about 22.5g/cube so each is about 22.5 ml.  I recalled it was not quite 1 oz, but I thought it was a bit closer.  Thanks for reminding me to verify my measurements Hande.

- Jeff