Author Topic: Understanding Rennet vs Floc Time vs Curd Cut Time Impact On Cheese > Bitter Taste Discussion  (Read 2623 times)

zulzie

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hello to  mr. queso.....

i've read your posts with great interest......you are doing the rest of us a great service sharing your experience and knowledge....and thank you for that......do you give classes?  i run a seasonal dairy from may to november with 20  jersey cows.....so, i can find time in the winter to come and work with you......

i am STILL confused on the relationship of how much rennet vs the floc time vs when to cut the curd vs what effect all of that has on the final cheese!   i must be dum.....  :)

lets say i want drier curds...is it RENNET LEVEL  that affects the moisture....or is it the HOLD TIME that i want to increase or decrease to affect the moisture level....or......is it BOTH?  (so confused!).....

the general advice from suppliers/books is you use half the rennet for a softer cheese (say a blue) than a harder cheese like a parm say......(cheddar in the middle?).....of course, this depends on your milk......at the beginning of the season, i make cheddar....i aim for a 45 minute hold time......i cut in half the amount of rennet recommended on the bottle to start.....over the first few days of cheesemaking, i vary rennet levels to get a 15 minute floc time, multiply that by 3 for a 45 minute hold, and check the curd for clean break at 30, 35, etc.....but generally  just wait for 45, if i got a 15 minute floc....

that all sounds like i know what i'm doing (i guess)  but i STILL DON'T UNDERSTAND what is driving the moisture levels and other effects.....is it the amount of rennet? is it the hold time?  is it a fluid relationship between both of those things?  if you use less rennet, and hold it longer, is that roughly the same as using more rennet, and holding it less?


dthelmers

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I'm not Mr. Queso, but I think I can help. The greater the flocculation multiplier, the moisture the curd, and also: the larger the cut size, the moister the curd. For a dry cheese like Parmesan, use a multiplier of 2 to 2-1/2, and cut the curds the size of grains of rice. For a moist cheese like Mozzarella, use a multiplier of 3-1/2, and cut the curds to 3/4" cubes.
Both the flocculation multiplier and the curd size control the  moisture content of the final cheese, along with how long you cook the curd, which expels more whey.
If my flocculation happened faster than my target, or perhaps I got distracted and didn't cut soon enough, I'll make up for that by cutting my curds a little smaller, and perhaps cooking a little longer, but watching I don't get too acidic by doing that. Stirring the curds a little more vigorously will make them a bit drier, too.
A practical example: I make Caerphilly regularly from the 200 Easy Cheese Recipes book. It comes out as it should, a bit crumbly. I wanted mine to be a bit moister, so I increased the flocculation multiplier from 3 to 3-1/2. I increased the curd cut size to 3/4" from 1/2"; then I followed everything else as written. My Caerphilly comes out moister, with the same flavor as before.

zulzie

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ok....thank you, that makes sense....

you mention:  "if my flocculation time is off my target"....that intrigues me.....what IS your floc time target?  are there floc times associated with different moisture level cheeses?  i have a floc chart thing, it only mentions curd cut size and floc multipliers....but not floc time... shouldn't we use floc times to fine tune rennet levels?  if there was a general "floc time" for cheddar, say......call it 15 minutes (i have no idea really, seems like 15 is about right if you use a multiplier of 3, and want a 45 minute cut time).......

then, you change your rennet levels to hit your 15minute floc time.....of course, acidity and temperature will affect floc time (and 100 other things no doubt).....but, if you are "in the groove" in your cheesemaking, and your milk does not vary, and your temp control is good, and your culture amounts and type are pretty consistent, then, the floc time should "only"  vary with your rennet level......

is floc time then taking these other factors into account, such as temp and acidity?  is that why we use floc time to fine tune curd cutting time?

because acidity will vary with the culture growth, and that acidity will affect rennet response.....so, the floc time gives us a way of seeing what is happening, on that particular day, with what the rennet is doing, and when to cut the cheese.....

dthelmers

  • Guest
ok....thank you, that makes sense....

you mention:  "if my flocculation time is off my target"....that intrigues me.....what IS your floc time target?  are there floc times associated with different moisture level cheeses?  i have a floc chart thing, it only mentions curd cut size and floc multipliers....but not floc time... shouldn't we use floc times to fine tune rennet levels?  if there was a general "floc time" for cheddar, say......call it 15 minutes (i have no idea really, seems like 15 is about right if you use a multiplier of 3, and want a 45 minute cut time).......

My target is 15 minutes for pressed cheeses. For semi lactic cheeses I don't pay attention to the floc time.

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then, you change your rennet levels to hit your 15minute floc time.....of course, acidity and temperature will affect floc time (and 100 other things no doubt).....but, if you are "in the groove" in your cheesemaking, and your milk does not vary, and your temp control is good, and your culture amounts and type are pretty consistent, then, the floc time should "only"  vary with your rennet level......

I have a pretty variable milk supply at times, sometimes using milk that has hit its sell-by date, so sometimes my floc time goes wonky.

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is floc time then taking these other factors into account, such as temp and acidity?  is that why we use floc time to fine tune curd cutting time?

because acidity will vary with the culture growth, and that acidity will affect rennet response.....so, the floc time gives us a way of seeing what is happening, on that particular day, with what the rennet is doing, and when to cut the cheese.....

Just so.

Sailor Con Queso

  • Guest
Good explanations Dave.

The floc time is your choice, but the idea is to be consistent. I too shoot for a floc point (time) around 15 minutes for most hard and semi-hard cheeses. That should stay the same. If you find that it is taking longer, then you can use more rennet next time. If the curd is setting too quickly, use less.

The floc multiplier is also your choice, depending on the cheese and what you are looking for. As Dave said, the longer the curd sets before cutting, the more moisture the finished cheese will have. So unlike the floc "point", the floc "multiplier" can and does change. For a Parmesan, you might use a 2.0 but for a Gouda, you might use a 3.5. As a cheesemaker, you make a cheese, wait 3 months, see how it turns out, and make adjustments on the next batch. Take good notes. ;)

Ed - aka "Mr. Queso"

zulzie

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i've had bitter cheese problems.....i googled it, and it seems that there has been some bad rennet on the market the past few years (i googled "bitter cheese rennet", or something like that)....i talked to dairy connection a year ago....they said that most animal rennet is made overseas, and both quantity and quality have been an issue...they didn't know who was making it, or much about it....but, it was in short supply...and high priced.....things seem to have calmed down this year

is there a maximum floc time and hold time for cheddar?  say, are you pushing the limit to wait 60, or even 90, to cut the curd.....say, a 20 minute floc, and a 60 minute cut...... and use less rennet?  maybe back off the culture volume slightly and delay acidification a bit.....is there an advantage of using the least possible amount of rennet to get the tastiest cheese?

 i also read that a pure LC culture....abiasa meso II (in the old book "cheesemaking practice"....seems to be very good, i just read a bit on google books)  without the LL takes longer to acidify, but makes less bitter cheese....here is a good link for a discussion of LL, LC....http://textbookofbacteriology.net/lactics_5.html


any recommendations on rennet source and brand to make sure that rennet is not causing the bitter problem?  and....is ill made rennet from mold cause more of a bitter problem than animal rennet? (i fight bitter cheese from mold, so it makes sense that rennet from mold that is not manufactured properly might be a problem....)

has anyone made some rennet from animal stomach?...i watched an interesting video by some italian guy who made his own.....i thought i'd harvest some veal this spring, get rid of some 3 week old bull calves, and try making some rennet.....





Offline JimP

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This is very interesting for me as well. Zulzie - thanks for asking these questions. Ed, Dave - thanks for the answers.

Floc time - once you've established all the other parameters for your make, ingredients, temps, procedures, desired moisture content, etc, as I understand it you choose your floc time (or maybe you are choosing it as a part of your procedure?).

The general consensus seems to be a 15 minute floc time.

Why?    Is it a matter of convenience (i.e., it's quicker than 30 minutes)? Would it make equal sense to speed up the process and adjust for a 5 minute floc time? Is 15 minutes as quick as the process can be pushed (e.g., the cultures cannot perform their magic any quicker? Is there something else in the thought process?

I've been spending most of my forum time time trying to get my mind around this huge body of information and neglecting giving feedback on what I've been making. I'll catch up on that soon. In the meantime, many thanks to all who help us by their updates and explanations!

Sailor Con Queso

  • Guest
A short floc time, using more rennet, can definitely cause bitterness. This is particularly true with non-animal rennet. A floc time that is too long, using less rennet, will produce a cheese that has to be aged much longer.

zulzie

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just talked to margaret morris.....she verified 15 minutes for cheddar floc time.....18-20 for softer cheeses.....but, said same 15 minutes for a hard parm type cheese......


she also indicated that this "science" is pretty nebulous....its a tool, but i don' think there is any definitive "model" of how this works .....i would love a scientific paper with all sorts of un-understandable equations and chemical reactions done, but with some usable conclusions.....and a simplified description of what chemically and physically is happening, and what  are the results of the rennet level tweaking, and the hold time tweakings......

linuxboy

  • Guest
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just talked to margaret morris.....she verified 15 minutes for cheddar floc time.....18-20 for softer cheeses.....but, said same 15 minutes for a hard parm type cheese......
A little surprised, and I disagree. Time to floc is largely a matter of pH at renneting. the rennet amount should not change that much among all hard cheese styles. For a softer cheese (bloomy rind), I would acidify to 6.45 ish. This would give me a time to floc of 12-14 mins. This is as it should be. It may even be less for stabilized types.

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she also indicated that this "science" is pretty nebulous....its a tool, but i don' think there is any definitive "model" of how this works
There absolutely are models, with many years of theoretical backing, research studies, and rheological assessments, including computer-aided determination of flocculation based on predictive modeling of components and sensor data. Most of it has been done in French by people working at INRA. There's actually very little left to discover in the science of enzymatic coagulation. We're still waiting for a better model of micellar function and structure, but coagulation is fairly well understood.

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and a simplified description of what chemically and physically is happening, and what  are the results of the rennet level tweaking, and the hold time tweakings......
I have posted a video and have discussed this before on the forums. To sum, all gellification depends on rate of reaction, which is influenced by acidity. The most important aspect is gel strength, both at onset when cutting, and later, the derivative function to determine velocity of gellification, which determines strength, which in turn determines syneresis rate, which helps to determine moisture content, which then influences rate of catabolysis during aging.