Hey all,

I’ve been a lurker on this site for years, and find it incredibly helpful and fun.  Now I need your help.  I have a mystery to solve with my raw milk that is failing to make cheese in a way I’ve never seen before!

I’ve been making cheese on and off for the last 7 or 8 years, depending on my milk availability.  I had a great raw milk source a year ago, and enjoyed success with fresh mozzarella and a few hard cheeses.  That milk source dried up, though, so I’ve been without fresh cheese for what seems like an eternity!  However, I finally found a new source last month, and have jumped right in to making fresh mozzarella once again.

The problem is that my 30-minute mozzarella is failing EVERY time with this new milk!  I’ve made it dozens of times before, using the same technique and different raw milk, and never had a failure before.  I know it’s not my technique or recipe… it’s got to be the milk.  I’m completely stumped as to why it’s failing.

Here is what is happening:  I add the citric acid, bring it up to temp at 88-90F, and add the rennet.  I let it sit until set, slowly rising to 100F, and that’s when it goes wrong.  I get a huge, globby mess like you see in the attached photo “curd_glob.jpg”.  When I try to cut the curds, I end up getting a super stringy and limp cheesy, cobwebby, mess, like you see in the attached photo “stringy_curds.jpg”.  Sometimes I’m able to get the curds strained enough to form a ball in the bowl, but it’s still limp, as if the cheese is melted.  This is before I ever heat it in the microwave, and when my whey is only in the 100-105 range.  I’ve never seen anything like it.  On the few times I’ve been able to get something resembling cheese out of it, it tastes bland but passable that day, and sour and waxy the next.  Sometimes it’s totally rubbery and plastic-y.

I’ve tried more rennet, less rennet, and slower heating.  I’ve even purchased a pH meter and checked to be sure that the milk wasn’t too acidic when I started out, but it was right at 6.5.  I tried testing my pH carefully after adding the citric acid, and made sure it was right at 5.2 before starting the process.  I even tried once with the old-school mozzarella method of letting it acidify on its own overnight, but the acidity never developed and the cheese bombed.  I bought new rennet, thinking that might be the problem, and that made no difference.  The last thing I tried was cutting the final temp back from 100F to more like 90F and I thought maybe it was going to work—it formed pretty nice curds and after draining I spun them and was able to form a fairly decent ball of cheese, but the texture was still way off.

I have two theories—either I’m still overheating it somehow or the cow has something in her diet that makes the milk fail like this.  I haven’t tried making any hard cheeses with this milk because I figure if I can’t even get a simple mozz to work, I sure don’t want to waste hours making a hard cheese and months waiting for it to age. 

Any advice you all have would be greatly appreciated!

Hi Sandra.  Nice to meet a lurker!

I sympathize with you in your dilemma.  I’m not a mozzarella maker, but the first thing that comes to mind is, as you said, a problem with the milk.  So I have to ask if you’re certain that your dairy person is using sterile techniques in the milking of the cow and the handling of the milk.  If the taste is sour on day two, I’d say it’s contaminated with an undesirable bacteria.

So, if you want to see if this is the problem, you’re going to have to pasteurize the milk before you make cheese.  One time ought to confirm the theory.  And, until you get this resolved, I’d recommend you don’t eat the cheese or drink the milk.

Let us know how it goes.  We’d sure like to get this resolved.

Thanks for the reply, Rich.  I get two gallons of milk every other Friday from a local Menonite farmer.  I’m due to get some this week, so I’ll try pasteurizing it and see if that helps.  Will report back this weekend!

Friday is my cheese making day, too.  I’ll be getting 4 gals of terrific Jersey milk.  Good luck.

Have you calibrated your thermometer recently?  I had to do mine as it was not reading correctly and my temps were way off.

To calibrate, you will need to put the thermometer into a glass of ice water and hold the nut on the back of the dial, and turn til the indicator reads about 32.5 degrees F.  Don’t do it with boiling water and water boils at different temps at different altitudes, but water will freeze at 32 degree regardless of altitude.

Just a thought.

I’m wondering how effective that method would be for the temps we need in cheese making.  When I worked in the processed food industry we had to use separate thermometers for cold and hot.  They had to be calibrated separately.  A cold calibrated thermometer could not be used to do hot temps.  Of course, this is only if you’re interested in very precise temp regulation.

Thanks for the suggestion, Kim.  I make a lot of hard candies and caramels, so I learned long ago the importance of thermometer calibration   I do usually test in boiling water though, not ice.  I’m not at any significant altitude where I live.

Green Cheese Maker - 07 May 2015 09:12 AM

I’m wondering how effective that method would be for the temps we need in cheese making.  When I worked in the processed food industry we had to use separate thermometers for cold and hot.  They had to be calibrated separately.  A cold calibrated thermometer could not be used to do hot temps.  Of course, this is only if you’re interested in very precise temp regulation.

Rich,

Good thought, but the temps involved in cheese making I would think would not be considered as Hot.  I learned of this calibration method from thecheesemaker.com.  The OP seemed to already know so probably a moot point anyway.

Kim, thanks for the calibration reminder.  I realized I had not done mine for a long while.  So I checked them this morning:  The one I use in the milk was spot on, but the one that I use to monitor water temp in the sink was off by almost 5 degrees.  These things can creep up on you if you don’t monitor them periodically.  So, again, thanks for the reminder.

Well, it took me all morning, but I just tried mozzarella again.  I pasteurized the milk first (held at 145F for 30 mins) then cooled it down to 90, and added the citric acid.  After letting it sit a bit, I added the rennet, then let it set up again.  I never added any more heat.  After the clean break, I cut the curds, let sit again, then drained.  I spun the curds in hot water to stretch them into a ball, which formed pretty well.  I did not get the super-stringy curds, likely because I never went above 90 (recipe calls for 100).  So in all, these were my best results yet.  However, they still weren’t right.  The cheese just doesn’t quite taste like it should, and took HOURS.  I don’t know if the pasteurization helped or if it was the low temps that got me through it.

I’m at a loss.  I think I need to find a new milk source :(

Well, at least you saw some improvement - that’s a positive.  A suggestion for pasteurizing that might be faster:  Instead of heating to 145 for 30 min, you can also heat to 161 for 15 seconds and achieve the same result. The double boiler method will prevent scorching and you won’t have to stir continuously.  Another thing involves cool down.  I’m not sure how you did that.  If you let it cool on its own, you may have left the milk in the high temperature zone too long.  After the heat phase, the milk needs to be cooled rapidly, like setting it in a sink of ice water.

If you can find another source for raw milk you’re fortunate.  Raw milk is not that easy to find.

I have a sous-vide / water bath setup that I use for maintaining temps, so keeping it at 145 for a half hour wasn’t difficult, and didn’t require constant stirring.  And I did cool it as quickly as possible by moving the pot to a sink full of ice water.

I really think the cow must be eating something unusual that’s affecting it, because I’m doing all the right/usual things, and not getting good results.  I’ll need to talk to the farmer about it.

I m with Rich in that theirs probably some contamination :(

Welcome to the Forum !

OP Check out this video, it may help you.  http://hoeggerfarmyard.com/make-mozzarella/

Thanks for sharing that vid, Kim.  I may actually do some myself.  I do have a question though.  I had heard that Moz should be made with skim milk.  Any problem with using whole cream milk?

Quick update: I stored some of Saturday morning’s results in a container, and it has turned pasty to the point where I don’t want to eat it.  This is the same results I’ve gotten with other non-pasteurized batches as well.  This batch was just stored in a container with a lid.  I’ve tried before in water and wrapped in plastic, and got the same results.

I’m going to call my farmer this week and tell him what’s going on and see if he’s got any info to share about the cow’s diet.  Will report back!