Author Topic: Long technical question about cheese bitterness  (Read 1153 times)

Offline ultrun

  • New Cheese
  • *
  • Location: USA
  • Posts: 2
  • Cheeses: 0
  • Default personal text
Long technical question about cheese bitterness
« on: December 27, 2012, 06:02:35 PM »

 Hi everybody.  This is my first post here.  I've been lurking for awhile.

I've been having consistent problems with bitterness in my hard cheeses.  I never have problems with fresh cheese (eg chevre, mozarella) or bloomies or fetas, only pressed cheeses (gouda, jack, cheddar, etc). 

These bad cheeses are also sharp (acidic) and sometimes have a pasty texture sometimes not.  I usually crack them open after about 4-6 weeks because I want to get this problem figured out before I start long aging cheeses.  Ones I have aged longer, say 6 months, continue to be bitter.

I use my own raw goat's milk.  It's freshly drawn, and I practice strict hygiene.  I haven't tried pasteurizing. 

My first thought was maybe the Ph was off (it's frustrating that so many cheesemaking books don't even mention Ph).  So I went out and bought a Ph meter, and made a half dozen wheels making sure I hit relevant Ph targets.  For example, I salted my cheddar at 5.2 and drained my gouda at 6.1. 

I also use about half the amount of starter a recipe recommends since I'm using raw milk (this is per the advice given by Caldwell in Mastering Artisan Cheesemaking and Kindstedt in American Farmstead Cheese). 

I use calf rennet and use about a third less than a recipe calls for.  For example, I used about 2.5 ml for a cheddar recipe using 3.5 gallons milk.    This is per instructions is 200 Easy Cheese Recipes that say goat milk requires less rennet.  I don't know the rationale for this.

I still find that I get a clean break faster than the recipes indicate, sometimes in half the time.  So I cut the curds as soon as a clean break is achieved.  Because of this early coagulation I may reduce starter and/or rennet amounts even more in the future, but it will be pretty hard to use less than I am doing now.  For example, I used 1/16th tsp of MA4000 for my 4lb wheel of cheddar (I don't have a scale that will weigh quantities this small, so I've been using tiny measuring spoons - tad, dash, etc.).

Nothing else seems unusual during the make.

Today I cracked open and tasted five wheels that I'd made since I got the Ph meter.   A pepper jack, a gouda, a cheddar, a tomme, and a lancashire.

Alas four of them had the bitterness defect.  The lancashire was the only one that tasted good.

Since I hit the appropriate Ph targets, I am guessing that it is not a Ph issue.  I'm also guessing it's not rennet related because I measure carefully with a pipette.  The only other thing I can think of is salt content. 

I looked over my notes and saw that the jack, gouda, and tomme (all were 3-4 lbs) were all brined in 18% brine for about 12 hours (flipped after 6).  I make fresh brine every time.  But one mistake may be that I don't use enough brine.  I'm not sure of the total volume, but it's less than the 1:5 ratio I now see is recommended.  More like 1:2.

The other thing that I noticed was that I over salted the lancashire relative to the recipe instructions.  I used 72 grams (morton canning and pickling salt), when 2% by curd weight would be about half that.  But when I tasted the lancashire it did not taste too salty.  The salt level tasted fine, and it lacked the dreaded bitterness.   I also noticed that I made the exact opposite mistake in salting the very bitter cheddar.  I accidentally used half the amount of salt called for in the recipe.   Oy!  Can you tell I'm no good at math?

For comparison I went back and tasted the bitter cheeses.  I could taste salt, but definitely not as much as in the lancashire.  My conclusion is that I've been inadvertently undersalting.  This strikes me as bizarre since I've been following recipe salting instructions (other than my two goof ups and having a perhaps too small volume of brine).

There may also be some naturally occurring lactic bacteria in my raw milk that, in the absence of sufficient salt levels, are producing bitter peptides(?).  If so, this may explain why the cheese reaches the clean break stage too early, is overly acid even when 4-6 weeks old.

This most recent milk is also late-lactation.  Though I've had the bitterness problem with summer milk also.  Kindstedt says that late lactation milk, because it's higher in fat, takes up less salt and needs to be salted at a higher rate.  He doesn't however give any indication of how much extra salt may be required.

So my question is, does any of this seem plausible?  Could something else be causing this?  If it is a salt problem, I can see how to fix it for cheeses where the curds are dry salted (ie just add more), but I'm not sure about brining.  Should I just up the volume of the brine to get the recommended 5:1 ratio?  Should I increase the brine strength and use a fully saturated brine?  Should I continue using 18% brine and increase the time in the brine.  If so, by how much?  Is there anything else I should try?

Kindstedt has instructions for testing salt content, which require special test strips.  If I can find them, I will test these wheels and that should give me a definite answer as to what the final salt content is. 

I'll also continue to age these cheeses to see if the bitterness reduces over time, but given my past experience I doubt it will.

I've read in other posts that certain cultures can be added to reduce bitter peptides (eg Choozit FLAV series), but I can't find a source for these locally or online. 

Sorry for the long post, but it's really frustrating having to throw out 75%+ of the cheese I make.  Thanks for your help


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


Offline Tiarella

  • Old Cheese
  • *****
  • Location: Chester, MA, US
  • Posts: 1,625
  • Cheeses: 71
  • Default personal text
    • Farm Blog
Re: Long technical question about cheese bitterness
« Reply #1 on: December 27, 2012, 06:28:06 PM »
Hi,  I'm no expert and I'm hoping Linuxboy will answer your question.  One other question?  What breed of goats do you have?  LB gave me some adjustment suggestions for those who use Nigerian Dwarf, Nubian or Lamancha milk.  The thread is likely in the washed rind section. (it was in the problem section but I think the webmaster has redistributed those) I started it and the thread title is something like "Help!  Washed rind style jumped ship". It's not easy for to go find it from this device but I think it's available.

Also, the brine you make; do you also add calcium chloride to prevent the brine from leaching the calcium from your cheese?  And may I suggest you save and reuse your brine as most cheese makers do? 

Hope others who know more will join this conversation.  I sympathize with how frustrating it must be to go to all that work and end up with something you're not enjoying the taste of!   :-\ :-X:-[

Offline bbracken677

  • Old Cheese
  • *****
  • Location: Dallas, Tx
  • Posts: 1,166
  • Cheeses: 16
  • I love me some cheese!
Re: Long technical question about cheese bitterness
« Reply #2 on: December 27, 2012, 06:54:54 PM »
Not sure how much this will help, but it will give you a solid indicator of how much rennet to use. Try using the flocculation method for determining when to cut the curd....you should aim for a 11-15 minute flocc time. If you are getting much quicker flocculation times than that then you can surely adjust your rennet quantity lower.

Search the forum for "flocculation" for the entire methodology and explanation, but in a nutshell it is this: after adding your rennet (record the time as accurately as possible) place a small light bowl (such as a plastic container, empty) on the milk and spin or nudge it every minute or so ....once the bowl stops spinning or sliding across the surface, sufficient surface tension has developed. This is the point at which you register the time (flocc point) and calculate how much time has passed since the addition of rennet.

For example: if you added rennet at 10:00 AM and at 10:12 the small bowl stops, then your flocculation time is 12 minutes. For a camembert, you would use a x6 multiplier and then cut the curd 72 (6x12) minutes from rennet addition...which in this example would be 11:12 AM. For Cheddar you would likely use a x3 multiplier and would cut the curd at 10:36 (10:00 AM + 36 minutes).

This is a more reliable (less subjective) method which will add reliability to your makes with regards to coagulation...not to mention it will nail whether you are using too much rennet (say, your flocc time is 6 minutes...too much rennet)

As to why your cheeses are too acidic...I will let those (such as LB) who know much more than I do on the subject...and indeed I am looking forward to seeing the answer myself, as I have had some acidification issues as well.

Offline Alpkäserei

  • Old Cheese
  • *****
  • Location: Indiana/Kanton Bern
  • Posts: 600
  • Cheeses: 62
  • Default personal text
    • https://www.facebook.com/Kaesereigrimwald
Re: Long technical question about cheese bitterness
« Reply #3 on: December 27, 2012, 09:18:49 PM »
What is the diet of your goats, and their living conditions?
I suggest a careful tasting of the milk and see if you can detect slight notes of theses undesired flavors prior to making cheese.

Guät git's dr schwiizer Chäser

Offline Toast

  • New Cheese
  • *
  • Location: Australia
  • Posts: 3
  • Cheeses: 0
  • Default personal text
Re: Long technical question about cheese bitterness
« Reply #4 on: December 28, 2012, 12:44:30 AM »
I'm keen for an answer to this question also.  We made a cheddar and aged it for 9 months only to find out that it has a nasty bitter aftertaste.  It has a good cheddar flavour initially but the bitter aftertaste completely ruins the cheese.  As with Ultrun's cheeses, our cheddar has a pasty texture (similar to a feta - white and crumbly, rather than yellow and firm).  After doing some googling and reading about Ultrun's trial and error, I'm wondering if the problem is bitter peptides from the starter culture that we're using (MO 030) which is a general mesophilic culture - a mixture of L. lactis ssp. lactis and L. lactis ssp. cremoris.  I'm wondering if some L. helveticus will help breakdown the bitter peptides and fix the problem? From one of linux boy's prior posts and Ultrum's experimentation the salt content may also be important, perhaps we didn't salt our cheese enough (despite following the recipe)? 

We are cheese novices but are finding that we have a bitter flavour in all cheeses we've made -  2 x blue cheeses (ripened for >2mths) and to a lesser extent a camembert (ripened for 2-3 wks).  The only cheese we made with no bitterness was a feta which only cured for 5 days.  All cheeses used the same MO 030 starter culture.  What starters are other people using and can anyone recommend another one to try that has not resulted in bitterness?


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


Offline Tiarella

  • Old Cheese
  • *****
  • Location: Chester, MA, US
  • Posts: 1,625
  • Cheeses: 71
  • Default personal text
    • Farm Blog
Re: Long technical question about cheese bitterness
« Reply #5 on: December 28, 2012, 06:50:48 AM »
Again, I'm no expert so I can only answer your question about what starters I've used without bitterness.  I've used MM100 series, MA4000 series, TA61, Abiasa Thermophile Type B, KAZU, MD88 and LM57. the last 2 are adjunct cultures used with others.  I've never had any bitterness in any of my cheeses.  I use raw goat milk from my tiny herd of Nigerian Dwarfs. 

Offline bbracken677

  • Old Cheese
  • *****
  • Location: Dallas, Tx
  • Posts: 1,166
  • Cheeses: 16
  • I love me some cheese!
Re: Long technical question about cheese bitterness
« Reply #6 on: December 28, 2012, 07:51:02 AM »

I read some thread on this site that I can't find again now that said that it could be that the culture needs another strand of something or other, or it could be not enough salt.


I believe that was Lactobacillus helveticus to be used in conjunction with T-61 type thermophilics



I have 4 gallons of raw milk to use this weekend and I am afraid to mess it up again. It's expensive.


One thing I am thinking about doing was a suggestion by someone, in order to reduce acidification, was to give the curds a quick wash before pressing (this would slow acidification during pressing).

Looking back, I think much of the acidification issues I have had may be due to excess acidity generated during pressing....Normally I begin my makes in the morning, so by 2-3PM I am pressing, which means that by the next morning (when I typically remove from the press) the cheese has been in the press for 18 hours (+-).  If this is causing the acidification issue I occasionally am seeing then I have, apparently, 2 options: a pre-press wash of curds, or drastically shorten the pressing time.

In the past I have not been able to check the pH of the cheese out of the press...

Offline Mike Richards

  • Mature Cheese
  • ****
  • Location: colorado springs, co
  • Posts: 446
  • Cheeses: 19
Re: Long technical question about cheese bitterness
« Reply #7 on: December 28, 2012, 09:05:55 AM »
I'm not an expert, either.  However...

I've had a number of bitter cheeses and most of my first cheeses had texture defects similar to what has been described (it's like every cheese I made was a bad feta in texture).  I have learned that that texture and the flavor, for my cheeeses, was a result of too much acid.  I got a pH meter and was able to hit the targets pretty well, but I still had the same problem.  I also had a floc time that was much too short.  I reduced my rennet each time I made cheese until I get the floc time in the 10-15 minute range (well, I actually got it at 21 minutes once, and then started increasing it into the right range).  Getting this right seems to have made a big improvement for my cheeses.

I believe in my case that the too short floc time led to higher moisture in the cheese (it's harder to get a good multiplier when I'm not sure whether it floc'd at 5, 6, 7, or 8 minutes), which ended up providing the culture more food than it ought to have had, allowing it to continue developing acid past when it should have stopped.

The next refinement, whose effects I haven't yet seen, is the use of my pH control charts.  Even though I have been taking the right steps at the right pH targets, sometimes I get to those targets much earlier than I've anticipated.  This, again, indicates that my acid is developing too quickly.  I use my charts to ensure that I follow the same time development of the acid, not just perform the right steps at the right pH.  I'm expecting this to improve the final cheese, too.

Using raw milk will usually (always?) require a reduction in the amount of starter culture you use.  Otherwise, you'll get too much acid development.  I'd suggest trying something like my chart and seeing how well you are actually following the path of the original recipe.  If you go faster, than likely you'll end up with higher moisture content and more acid.

One final thought on salting.  Insufficient salting can also lead to continued culture development and too much acid development.  When you salt, if you're not careful, you can lose a lot of the salt to the whey (especially if your curds start out too moist).
If only I could make cheese as well as I grow a mustache...

Offline bbracken677

  • Old Cheese
  • *****
  • Location: Dallas, Tx
  • Posts: 1,166
  • Cheeses: 16
  • I love me some cheese!
Re: Long technical question about cheese bitterness
« Reply #8 on: December 28, 2012, 09:50:32 AM »
Makes sense....a combination of too much moisture and too little salt would do the trick.

Offline MrsKK

  • Old Cheese
  • *****
  • Location: Wisconsin
  • Posts: 1,875
  • Cheeses: 61
  • Default personal text
Re: Long technical question about cheese bitterness
« Reply #9 on: December 28, 2012, 10:05:07 AM »
The proper amount of salt can help expel more whey, too.  Proper pressing with enough weight and for enough time are vital to reducing the amount of moisture in the cheese.

I think the salt amount is the answer to the OP's question, as the Lancashire was not bitter, but had more salt added to it!


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


Offline bbracken677

  • Old Cheese
  • *****
  • Location: Dallas, Tx
  • Posts: 1,166
  • Cheeses: 16
  • I love me some cheese!
Re: Long technical question about cheese bitterness
« Reply #10 on: December 28, 2012, 10:35:37 AM »
The proper amount of salt can help expel more whey, too.  Proper pressing with enough weight and for enough time are vital to reducing the amount of moisture in the cheese.

I think the salt amount is the answer to the OP's question, as the Lancashire was not bitter, but had more salt added to it!

Great Sherlocking!   :)

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 199
  • www.wacheese.com
    • Washington Cheese Guild
Re: Long technical question about cheese bitterness
« Reply #11 on: December 28, 2012, 10:39:31 AM »
short bitterness cause overview:
- Water drives reactions between molecules
- For protein, water facilitates the breakup of protein chains into peptides
- For fat, water facilitates breakup of long fats into FFA chains and then into flavor and aroma compounds
- For sugar, water facilitates breakup of di-sugars such as lactose, and then the monosugars

Of these, bitterness is most often caused by peptide chains from portions of caseins. b-casein, for example has several portions that are very bitter.

There are generally several causes of this:
- Too fast or mis-timed rate of protein breakdown due to too high of a moisture, inadequate salt, too high aging temperature, excess residual rennet or too-proteolytic rennet
- Contamination in paste from bacterium, yeast, or mold that has enzymes that cause the wrong kind of protein (and fat) breakdown. Specificity of those enzymes targets different portions of protein
- contamination in rind, same, causes excess breakdown or wrong breakdown
- milk is off. sometimes in late lactation, milk has too much natural enzyme and it doesn't work well.

to remedy:
- excess moisture: use floc, make sure you hit moisture target
- salt level: measure correctly and model salt/brine schedule for your cheese type and form factor.
- aging temp: control for your cheese style. may need to lower
- general protein breakdown: use adjust such as lb paracasei, casei, lb plantarum, lb heleveticus to facilitate converting larger bitter peptide chains to smaller ones.
- contamination: audit sanitization and hygience practices, possibly thermize/pasteurize
- rennet-related causes. Switch rennet or make small batches with different amounts to rule out or confirm.
- milk. sometimes not much you can do, but usually diet-related. check mineral schedule, worm loads, overall feed nutrition

In your case, most likely cause is something related to moisture/salt combos.
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: Long technical question about cheese bitterness
« Reply #12 on: December 28, 2012, 11:33:46 AM »
Thanks LB!

Great explanation of the potential causes for bitterness! 

Offline ultrun

  • New Cheese
  • *
  • Location: USA
  • Posts: 2
  • Cheeses: 0
  • Default personal text
Re: Long technical question about cheese bitterness
« Reply #13 on: December 28, 2012, 11:45:29 AM »
Thanks for the help everybody.  I'll try again this weekend, watch floc time, triple check my math for salt, and let you know how it goes.  I think I'll try making a couple smaller wheels and salting them at different rates.  All else being equal, if that fixes the problem, then I'll at least know the cause, and with some tinkering can find rates that work for me.

To answer a couple of the questions:
My goats are Oberhasli - not a breed known for high fat production.
They eat pasture in the summer supplemented with a locally produced natural (though not organic) grain.  In the winter their hay comes from my pasture.
Their milk tastes beautiful-  not a hint of off or bitter flavor.  Also other (fresh) cheeses don't have this problem, so it must be something with the chemical reactions happening in aging. 
Their barn is clean, and I am super careful about milk hygiene, so I doubt that's a factor.
Also the particular starter culture doesn't seem to matter.  At least among the four or five I've tried, the results have been similar.  Though I haven't made any aged cheeses with Thermo cultures yet.

Offline linuxboy

  • Old Cheese
  • *****
  • Location: Ukiah, CA
  • Posts: 3,986
  • Cheeses: 199
  • www.wacheese.com
    • Washington Cheese Guild
Re: Long technical question about cheese bitterness
« Reply #14 on: December 28, 2012, 12:32:09 PM »
Good luck. If it's still not working for you even with lower aging temp, higher salt, and lower moisture, get some adjunct lactobacilli to help complete the bitter peptide conversion.
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.