Rennet - Recommendations > Discussion On Types

[linuxboy]

Thanks . Finally finished the majority of that article on coagulants. One more section to go that has the major rennets listed along with their clotting strength and amount to use for common cheese styles. Will update it when I can.

http://www.wacheese.com/index.php?option=com_content&view=article&id=73

[Boofer]

I'm somewhat comforted that I may have identified a flaw in all of my previous cheeses...14...count 'em!     Thanks to linuxboy's clarification of rennets. I do realize I may have other process problems, but changing the rennet should at least eliminate some of the bittering that I may have been building into my cheeses.

I recently received calf rennet and will be using it for all my future cheeses. In fact, I am really anxious to redo some recent endeavors and sock them away for awhile.

Why do the cheesemaking kits have the m. miehei coagulant? Arrrggh!!    I wouldn't expect it to be that much of a cost differential. All kits for beginning cheesemakers should include animal rennet, right? Unless the prospective cheesemaker intends to only make young, fresh cheeses, why would these folks torpedo the unsuspecting beginner? It's just wrong. I have yet to make a fresh, unaged cheese. They have all been intended to be aged.

linuxboy, your work looks good so far. Can you characterize the damage to whey proteins caused by the M. Miehei as described here?:

"Microbial coagulant, such as one derived from M. Miehei breaks down whey proteins very quickly, causing damage as soon as 3-4 hours after addition. Whereas, other enzymes, such as animal rennet and FPC have negligible impact on whey proteins."

-Boofer-

[linuxboy]

Well, Boof, some people are vegetarian and avoid all GMO foods, so their choice is either m miehei or real coagulant from plants like cardoon. Also, yes, that is the cheapest rennet out there. I have no idea why anyone still sells m miehei without posting a clear description of the rennet options. Perhaps lack of research, or just stocking an item for the sake of selling it. There are applications for m miehei.

What kind of characterization would you like to see? Rate of proteolysis vs animal or FPC? Explanation of the specific sites in whey proteins affected? Factors influencing amino acid hydrolization? Discussion of organoleptic properties of the liberated peptides? I am trying very hard to not write too much because honestly, a lot of this stuff is kind of useless unless you're a scientist. No sense in obfuscating the important stuff for the sake of exactness. It's also why I chose to not have citations to all the research studies.

In terms of the effect on whey, because those whey proteins are cut, they can't be recovered well during industrial whey concentration. You get fewer solids, and the price paid for whey is for the solid fraction. So a plant making 10,000 liters may get $20 per lb of whey solids, but if those solids aren't there, then they're out of money. It's pretty dramatic in huge plants that can get money for the leftover whey. Practically for home cheesemakers it means a whey ricotta is difficult to achieve when using m miehei.

[Boofer]

You're right. What you present rapidly approaches TMI (too much information).

You did satisfactorily answer my question. If the whey solids are destroyed and not recoverable, probably no (or less) ricotta cheese is possible, correct? A lot of weight-lifting and body-building products use the recovered whey product. I can see how that would be affected.

And, yes, I do see the need for a non-animal-based coagulant.

-Boofer-

[linuxboy]

Glad that helped. If something is unclear, please, please let me know if you can. I go over and revise what I write repeatedly to take out the excess fluff, but it's hard for me to judge sometimes what is relevant and what isn't. I try to include a lot of "this makes the cheese taste XYZ" and "don't do this because" type of writing.

Yes, whey ricotta is made from the whey proteins, not the casein proteins. Those whey proteins are denatured when they are heated, which means they are unwound and can clump together and come out of the whey as solids. If the proteins are cut to smaller bits they can't be unwound in the same way when they're heated, so they don't come out of solution (meaning yes, less or no ricotta yield). In terms of commercial practice, smaller bits of proteins aren't as heavy, and they're physically smaller, so it's not as easy to use commercial methods like a membrane that filters specific sizes of proteins, or centrifuging.

[Gina]

Follow up report:  I just opened the first cheese made with my 'new' dry calf rennet (Purchased because of this thread - I formerly used microbial rennet.) It's an Asiago, meant to be aged longer, but I was curious. Even though it is still young, it is extremely good and I am very pleased with it. So pleased I made another one yesterday.

My taste buds are very sensitive to even slight bitterness (super taster), and there isnt any at all with this. Of course it's not possible to really tell if it's the new rennet that's responsible, or that my skills/knowledge have improved, or blind luck. No matter the cause, I'm very pleased.

Also, it's my impression that I am getting better set and firmer curds with the animal rennet, but that could be my imagination.

I am finding using the dry rennet to be very easy. My cheeses are usually 4 gallon ones, and I have made pre-measured little packets containing 1/8 tsp so measuring isnt necessary each time.

[Boofer]

I'm with you, Gina. I formerly used mucor rennet and have recently switched to calf rennet because of linuxboy's tutelage. So far, I have a Gouda and my Beaufort that have been made with the dry calf rennet. Unfortunately it will be quite some time before I can taste the Beaufort (try this same time next year!), but the Gouda should be available by Halloween. I'm very curious.

Congrats on having your supertaster approve the Asiago. Woo woo!!

-Boofer-

[linuxboy]

That's so great to hear! Congrats. It's amazing because there is so little rennet left in the cheese after draining whey, but it makes a world of difference which one you choose.

[KosherBaker]

Thanks . Finally finished the majority of that article on coagulants. One more section to go that has the major rennets listed along with their clotting strength and amount to use for common cheese styles. Will update it when I can.

http://www.wacheese.com/index.php?option=com_content&view=article&id=73

Wow Pav.

Great article. Thank you so much for putting it together. Just in case you are looking for feedback. Here are some points from a complete noob cheese maker. 

1. In the section on Plant based coagulants, you mention the bittering effect that they have on milk. However, the following paper seems to claim that this is true for cow's milk only (or mostly?), and that for goat and sheep's milk cheese Plant based coagulant may actually be preferable. They profiled Cynara L. usage in Spain and Portugal, which appears to be the purple section of the artichoke and cardoon flower.
http://www.google.com/url?sa=t&source=web&cd=1&ved=0CBIQFjAA&url=http%3A%2F%2Fwww.net-lanna.info%2FFood%2FArticles%2F11024336.pdf&ei=FPpyTKuGL4GesQOS76GoDQ&usg=AFQjCNEjMTJFp9Y-v5FBdFH6afSIhIT-9g&sig2=w8mR2_iQILQeBpEOnZyidA
Now I'm a total noob as I mentioned so it may be that I misunderstood something. So am very much looking forward to your (and everyone else's) feedback on this.

2. Do any enzymes come from starter cultures (the Meso- and Thermo-)? The reason I ask is because they appear to be able to produce curds. Especially the buttermilk. Are they the same enzymes as the ones found in the different types of rennet?

3. The following sentence confused me a little bit:

Enzymes coagulate milk by destabilizing the casein proteins, which causes them to join together and form a stable gel.

By destabilizing/cleaving I understand that the kappa and alpha/beta bonds are broken. So once they are separated what do they attach to in order to form the curd?

4. Would you consider an Acid as another form of coagulant? Like for example Vinegar or Lemon Juice and such? I thought I'd mention it as it may help draw the bigger picture of how the coagulation process works.

5. For those forced to use coagulants that yield bitter taste. I would love to see a list of things that can be done to minimize that. Like for example I saw on a Youtube video that washing the curd before pressing it will minimize the bitterness in the cheese later on. Sure enough reading an article sometime later it was mentioned that excess acid in the curd will cause bitterness in the cheese after it is aged.

6. Now the following is not related to coagulation, so it may be irrelevant for your article. But I thought it would also be good to know why acidity turns to bitterness during the aging process. And which acid(s) are responsible for that?

Again thanks for the great article, and I hope nothing above comes off critical or negative in any way.

Rudy

[linuxboy]

That is so super helpful. Thank you so much. I'll make some changes after ACS. To answer your questions:

1. In the section on Plant based coagulants, you mention the bittering effect that they have on milk. However, the following paper seems to claim that this is true for cow's milk only (or mostly?), and that for goat and sheep's milk cheese Plant based coagulant may actually be preferable.

I wouldn't say preferable. I would say that for casein structures other than bovine casein when used with raw milk that has native bacillus and cocci strains with peptidases and proteases, the end product exhibits acceptable flavor without excess bitter notes. I would also say that for highly proteolytic and peptidolytid/lipolytic cheeses such as ones with bloomy rinds or blue mold, the degradation of proteins by those enzymes is so much higher and faster than the protein degradation from aspartic proteases that the bitterness is mitigated. It's like if there are any extremely hydrophobic peptide terminals in the cheese, they're further broken down by the other enzymes from bacteria and molds.

2. Do any enzymes come from starter cultures (the Meso- and Thermo-)? The reason I ask is because they appear to be able to produce curds. Especially the buttermilk. Are they the same enzymes as the ones found in the different types of rennet?

Yes, a lot of enzymes exist both within the cell membrane, within the cell body in the fluid, and in the cell components. They come into play in the cheese texture, flavor, and aroma development. But coagulation due to acid that produces a lactic curd is due to two dynamics. One, the production of acid to lower pH to the isoelectric point of milk (4.6), which destabilizes the positive charge of the k-caseins to the point where milk can no longer be a colloid, and Two, the polysaccharide structures on the cell membrane contribute to a thick set. That's why Leuconostoc, for example, produces a thick set, its exo-polysaccharide structure is conducive to cell joining into chains.

By destabilizing/cleaving I understand that the kappa and alpha/beta bonds are broken. So once they are separated what do they attach to in order to form the curd?

Cardosin and chymosin have initial specificity only toward k-casein. k-casein is hydrophilic in its terminal, has a net positive charge on that terminal, which lets the casein structure remain in suspension. as1, as2 caseins are hydrophobic, they cannot be in suspension and will join to each other via calcium bonds. I posted a video here. Search for my post, something like "must see:video that explains the science behind coagulation." The k-casein is oriented with its hydrophilic terminal out, and that's the part that's broken off by chymosin/cardosin to liberate a glycopeptide. The other section is called para kappa-casein, highly hydrophobic.

4. Would you consider an Acid as another form of coagulant? Like for example Vinegar or Lemon Juice and such? I thought I'd mention it as it may help draw the bigger picture of how the coagulation process works.

That's true, I didn't mention it because I didn't want to get into the whole discussion of milk chemistry. But you're right, I should add it and touch on it for completely.

5. For those forced to use coagulants that yield bitter taste. I would love to see a list of things that can be done to minimize that. Like for example I saw on a Youtube video that washing the curd before pressing it will minimize the bitterness in the cheese later on. Sure enough reading an article sometime later it was mentioned that excess acid in the curd will cause bitterness in the cheese after it is aged.

For what kind of cheese? For hard cheese that's aged a long time? It's a toughie. For active bloomy rind, blue, and fresh cheeses, it's easier. Upping the protein content is one good trick to reduce bitterness with m miehei. I'll add a section, thx.

6. Now the following is not related to coagulation, so it may be irrelevant for your article. But I thought it would also be good to know why acidity turns to bitterness during the aging process. And which acid(s) are responsible for that?

It doesn't by itself. It depends on the cheese and rate of degradation and whey drain pH (which affects calcium in the cheese). So what happens is that as cheese ages, it will break down by itself. The coagulant enzyme helps, and so do proeteases and peptidases. But cheese protein will also break down all by itself in the presence of water due to classic hydrolysis. So what happens with high acidity development is that often it's not the acid itself but the other factors. For example, say you miss the brine target of 5.4 and wind up brining at 4.9. High acidity, right? Yep, but what has that acid done to the cheese while it has been sitting? Well, it's degraded the calcium bonds both between individual caseins and the bonds between micelle structures. This is especially the case when the whey drain pH was low. So by the time you salt, those proteins have been "predigested" by the acid. And then during aging, because the knit is poor, the rate of proteolysis is faster. If you take two cheeses and change either drain pH or salt/brine pH, the rate of protein degradation during maturation will be different. The lactic acid by itself doesn't really do all that much. It's converted to lactate salts most of the time.

Remember bitterness and it's taste is a peptide chain. A peptide chain is liberated when proteins break down. And those proteins break down due to catabolysis (i.e. protein hydrolysis), usually with the help of an enzyme that has specificity to certain amino acid bonds in a protein.


Thanks again. I'll rewrite portions and improve what I wrote. One disadvantage of online publishing like this is no peer review, so this is a big help.

[KosherBaker]

Wow what an awesome forum. I need a thumbs up graphic.

5. For those forced to use coagulants that yield bitter taste. I would love to see a list of things that can be done to minimize that. Like for example I saw on a Youtube video that washing the curd before pressing it will minimize the bitterness in the cheese later on. Sure enough reading an article sometime later it was mentioned that excess acid in the curd will cause bitterness in the cheese after it is aged.

For what kind of cheese? For hard cheese that's aged a long time? It's a toughie. For active bloomy rind, blue, and fresh cheeses, it's easier.

It was indeed for a hard cheese that is meant to be aged a long time over 6 months and up to a couple of years, at the extremes.

Upping the protein content is one good trick to reduce bitterness with m miehei. I'll add a section, thx.

I'm really really looking forward to that. Knowing the protein types and where to extract them from will help us insure cheeses that are meant for the cave/aging.

Great Stuff Pav. Thank You very much.