Started by wauserfriendly, March 07, 2022, 07:16:09 AM

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Thanks.  I'm sure these have been asked all the time and I appreciate those of you who have to read them again and again.

I've been making my own yogurt for close to 50 years.  I'd like to build on this to produce things other than greek yogurt or soft high acid cheeses like cream cheeses.

I heat my milk to 180 then cool it rapidly to about 110. 
Then I add some yogurt, often mixed with a can of condensed milk, stir and incubate abt about 110 for about 8 hours.

Sometimes I strain the whey away for greek style, or even more away for something akin to cream cheese.

10 Can I make other cheeses, perhaps hard cheeses from this?  I have made something like boursin by adding herbs and some oil.

2) I know there's too much lactic acid for something like mozarella or swiss.  But if I stop an hour after incubation, could I make other hard cheeses from that?

3) Whenever I see directions for other cheeses, they talk about wiping away mold, or using vinegar.  How can we be sure that we have mold that is not so toxic?  Do the bad molds just not grow on milk products under certain conditions?  How can I make sure I'm safe?   I have similar concerns for aged beef as well.

I should also mention that I live in an apartment, so the temperature is roughly 70 all the time.  Of course I do have a refrigerator.   But I can't keep something at other temperatures.


Let me put it this way: you *can* do different things, but it won't be easier  ;D

OK.  It's an excuse for my favourite topic: acidity and acid coagulated cheeses.  Let's see if I can do it this time in less than 5 million words...

Acid coagulated and rennet coagulated cheeses are different.  Rennet works by modifying the protein in milk so that it can all hook up together using calcium as a glue.  The gel that it makes is relatively quite strong.  You get a rubbery, strong cheese.  Also, rennet will work with relatively little acid.  In fact, you can make halloumi with no added acid at all -- basically the same acidity as milk.

The proteins in milk are normally "hydrophilic".  This means that they love water.  They stick close to the water.  When you add acid, the proteins stop liking water so much.  When you add enough acid, they don't like water at all.  This is called "hydrophobic".  They race away from the water and kind of clump together.  The clumps are weak, though.  It's more like sand in a sand castle than the rubbery cheese of rennet cheeses.

There are 3 very important things to understand if you want to make acid coagulated cheeses:  First, the faster the water becomes "hydrophobic", the faster it rushes away from the water and the bigger curds it makes.  If you add acid very slowly, over a period of several hours, the curds will often be so small that you can't even see them.  Even though the proteins are hydrophobic and clumping together, those clumps are super small and so you end up with basically something that flows -- yogurt.  If you add all the acid you need very quickly, say 2 seconds, the curds will clump very large.  You can get curds that are several cm in size (bigger than an inch) and you will see the curds and whey split.

The next most important thing is that heat damages the proteins in milk.  If you bring it up to a high temperature, the whey proteins get all scrambled up (exactly like cooked eggs) and they get tangled up in the protein that we generally use for making cheese: casein.  This means that the proteins won't clump as well.  The tangled up proteins *also* trap water, which makes your yogurt thicker, but also makes it harder to drain when you are making cheese.  The less heating the milk has, the easier it is to make large curds of cheese that drain well.  Ideally you should use pasteurised milk (or raw milk if you are OK with the minimal risks involved with that).  You *can* make acid coagulated cheese from UHT milk, but it's easier without -- which is the opposite from yogurt.

Finally, the amount of acid you need to coagulate the milk depends on the heat of the milk.  Usually we measure acidity with the pH scale.  Lower numbers are more acidic than higher numbers.  Normally yogurt  forms at room temperature at a pH of about 4.8 (the same as feta, blue before you add blue mold or camembert before you add the white mold).  If it is 50 C, the pH is more like 5.3 (about the same as mozzarella or cheddar cheese).  If it's 85 C, the pH is more like 6.1 (the same as ricotta cheese, because that's how you make it ;-) ).

You can control the acid level of your cheese by heating your milk to a specific temperature and then adding acid until the curds form.  Because you add the acid quickly, you get large curds that are easy to drain.  Unfortunately, acids that you add to milk do not make very delicious cheese.  Also, if you age the cheese, it lacks the enzymes to produce nice flavours.  So it will always be lacking.  However (and this is the magic), you can go the other way around!

In other words, grow your yogurt bacteria in the milk until you get the acidity that you want and then heat it quickly to form the cheese.  Because you are using a fermentation process, you get nice flavours, you get lactic acid instead of citric acid (or acetic acid) *and* you get enzymes from the culture that will eventually produce nice flavours as the cheese ages.  Hooray!  And because you heat the milk quickly to get to the point where it curdles, you get big(ish) curds that drain easily.

The main thing is practice.  You add your culture.  You leave it at a specific temperature (depending on the culture) for a certain amount of time, you heat the milk until it breaks,  you drain it, you press it lightly, you salt it.  You age it.  Bob's your uncle.  (I don't know if the last bit is true...)  But it will take time to get to know your cultures.  One word of warning: If you leave your culture so long that it makes yogurt, it has *already* coagulated.  it won't coagulate again.  So in order to get big curds you want to heat it wile the milk is still milk.  (BTW, this is not true for some types of cheese.  There is a famous style of brie cheese that is made by draining yogurt, probably in a similar manner to what you are already doing.  Edit: I forgot to mention that to get a nice solid cheese from draining yogurt, normally you need to drain it at room temperature for at least 3 days -- sometimes it takes my cheeses as long as a week to get to the consistency I want).

There is much, much, much more to this, but I promised to keep it as short as I could.  It's enough to get you started, anyway.  There are many traditional acid coagulated cheeses that are aged.  Some are soft cheeses, but some are hard cheeses too.  They have a different texture and flavour than rennet based cheeses, so don't expect to duplicate cheeses from the store.  Having said that, though, the cheeses are *different*, not worse.

I will leave you with one last thing, though.  Keep in mind my first words: this is not easier than rennet based cheeses.  In many ways it is *harder* to make quality cheese this way.  I have to admit that I probably make almost as much acid coagulated cheese as I do rennet coagulated cheese, but I'm crazy.  You don't have to be crazy.


Going to reply to my reply for the other questions:

1. Already answered.  Yes.

2. You can't make swiss or mozzarella this way (especially mozzarella) as the curds are not strong enough.  Like I said, you can make a variety of different cheeses.

3. Generally things that grow on cheese are not toxic.  Make sure to salt your cheese reasonably and keep the water content low.  I recommend *never* wiping with vinegar for very technical reasons.  Mold grows on cheese.  Embrace it.  Your goal is to set up the environment so that the things you want to grow on the cheese do.  That's a massively huge topic.

You should start out aging your cheeses in your fridge.  I've finally done enough testing to say that this works: Make sure that the cheese is fully drained and touch dry before you start.  Let it sit at your perfect 70 F, flipping it every day until it's just touch dry (or at least not shiny).  If the rind starts to dry out and change colour, you've waited too long.

Wrap the cheese in 2 layers of paper towel.  Put that in a ziplock bag. Put that in the fridge.

Take it out and flip it every day, inspecting it for mold, etc.  If the paper towel is soaked, replace it.

Rub off anything that grows on the cheese with a dry cloth, but if you feel adventurous, leave anything that's white and rub off anything that's blue.  If you get orange, it's because the bag is too wet.  Take everything out and let it dry.  If blue is taking over, then just clean it off with a 5% brine solution (5 grams of salt per 100 grams of water), dry off the cheese and then eat it.  With practice, you can coax your cheeses to age longer, but life's too short to fight crazy blue mold.

Once you have mastered being able to age cheeses in the fridge for say 2 months, then get yourself a picnic cooler.  Add an ice pack and a bottle of water to the picnic cooler.  Keep your cheeses in there.  Try to time changing the ice so that it maintains a 50-55 F temperature.  You will probably have to change the ice once a day.  If you go away, just put it in the normal fridge while you are gone.  With practice, that picnic cooler is as good as any cheese cave in the world.  It's a pain in the bum, but good.

Once you are sick of that, hopefully you've saved up for a cheese fridge :-)

Again, there is *so* much more to this, but that's all I have time to type tonight.


Lots of good information. I'm on the autistic spectrum and I sometimes stick to a path and sometimes need to ask questions differently.  I need to understand why.

I think I get the first step is to create curds of the proper size for the cheese you desire.  I know that heat or acid will coagulate proteins.  Can I just add acid to get to the desired pH?  Or can I just heat to get the proper coagulation?  Or just let the little beasties to enjoy a yummy lactose meal and to excrete lactic acid into the milk?  (We could just call lactic acid "bacteria pee."  Thank you, Hans Krebs.) Is the concept to GET the pH to (in the cases you cited 4.8, 5.3, or 6.3) and develop at that pH?  Or are you saying that will be the resulting pH?

I can add citric/acetic acid to the milk to get it to the desire pH. I've done that with ricotta/mozzarella.

I can also get the pH to lower using the bacteria at a temperature that makes them happy and let them convert lactose to lactic acid.

If I stop fermentation when the pH gets to 5.3, I'd have larger curds and could then be at the first step to making something like a cheddar?

I know heat will coagulate proteins, just like acid will.  Why can't this be done entirely with acid, or heat, or with the bacteria?

f I get the pH (using acetic/citric acid) to 4.8, I can make yogurt.  If 5.3, mozarella/chedar, 6.1 ricotta.

A few things are unclear.  I read the following:
QuoteNormally yogurt  forms at room temperature at a pH of about 4.8.... 50 C, the pH is more like 5.3 (about the same as mozzarella or cheddar cheese).  If it's 85 C, the pH is more like 6.1 (the same as ricotta cheese, because that's how you make it ;-) ).

Are you saying that the pH automatically changes if I just heat the milk? Or are you saying that the pH will change if I add yogurt and incubate at those temperatures? I think you are saying that each cheese develops at that pH.

I know I can add a given quantity of vinegar/lemon juice to give me the right pH.  But if I add bacteria (yogurt), the little beasties will take a bit longer converting the lactose to lactic acid, thus giving me the proper acidity.

I get that I should use the yogurt to get to the right acidity and then heat.  I have enough memory and understanding of the chemistry.  Your explanations have helped me understand.

I have pH test strips.

I see a few options:
1) Heat the milk to about 80c, then cool down to 35 c.  Add yogurt.  Wait until ph = ?
2) Warm milk to 35 c.  Add yogurt.  Wait until ph = ?
3) Start with room temperature or cold milk.  Add yogurt and keep at room temperature.  Wait until ph= ?


I think I need to clear up a misunderstanding:

I know heat will coagulate proteins, just like acid will.

This is not correct.  You can only coagulate proteins with acid.  Heat reduces the amount of acid that you need.

Are you saying that the pH automatically changes if I just heat the milk?

No.  The curds form at a higher pH when the milk is hot.  The hotter the milk, the less acid you need.

The key to big curds is to either add acid quickly, or heat the milk quickly to the point where it will coagulate with the amount of acid that it contains.

Letting the bacteria grow in the milk produces acid.  It produces it slowly.  The curds are therefore *very* small.

You can let the bacteria grow in the milk until you have *some* acid and then quickly heat the milk to get the milk to coagulate.  This will produce big curds.  This is the best way to make acid coagulated cheese.

I've just written this quickly because I have to run, but I'll try to answer better a bit later.


Do you have any cheesemaking books? I think you would really appreciate Gianaclis Caldwell's Mastering Artisan Cheesemaking. That's my favorite, with great recipes and a great overview on how everything works.


As a start, use option 2.  Heat milk to 35 C, add yogurt.  Hold it for about 3 hours.  Heat until it coagulates.  The more acid you produce in the 3 hours will mean the *lower* the temperature it will coagulate at.  Adjust the amount of time you wait to hit the temperature you want.  I recommend starting with trying to coagulate the milk at 50 C (which would be traditional for Ayib cheese).

If it curdles at a temperature higher than 50 C, next time wait longer.  If it curdles at a temperature lower than 50 C, next time wait less time.