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GENERAL CHEESE MAKING BOARDS (Specific Cheese Making in Boards above) => Problems - Questions - Problems - Questions? => Topic started by: scasnerkay on February 28, 2012, 11:07:53 PM
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There were no responses to my question in when posted under Swiss cheese, so I am trying again....
This is my first cheese with PS, and I am following the recipe in Artisan Cheese Making. I think my pH meter was not be functioning correctly, because though the make progressed along just fine, my pH meter kept reading no lower than 6.5. So either the acid level was developing more slowly than I expected, or is it broken?
Jarlsberg –type cheese
2 gal non-homoginized whole milk, pH 6.7
1 pre-measured packet Thermo C (ST and LH) about ½ tsp
1/8 tsp ps
¼ tsp calcium chloride
1.75 ml calf rennet
12:00: heating in heavy bottomed pot on diffuser plate over low flame
12:30: temperature at 92 degrees
12:38: done stirring in cultures, resting at 92 degrees for about 45 mins
1:35: done stirring in calcium chloride and rennet (each diluted in ¼ cup water)
Flocculation at 14 mins, clean break at 49 mins
Curd cut about 3/8 inch and rested 5 mins.
2:30: Temperature 90 degrees, pH 6.6
Stirred gently for 20 mins, with flame as low as possible to bring it back to 92 degrees.
3:05: Whey removed to level of curd, replacing with 140 degree water to bring to 100 degrees
3:45: Temperature now 108 degrees, pH still says 6.6
I think something might be wrong with the meter, because the curd feels ready. It is squeaky, and readily wants to knit together when I stop stirring. So I go ahead with draining the whey.
Pressed in mold in whey for 10 mins with 10 #
Removed from whey into standard press with 10 # for 30 mins, and meter now says pH 6.7
Meter re-calibrated
Cheese flipped and re-dressed and pressed with 20 # for 1 hour.
Cheese flipped and re-dressed and pressing with 30 # for I am not sure how long to go.... pH is 6.5 then 6.6.
9:00: Getting anxious because I would like to go to bed at some point. Now at 40 # to try and get some whey to measure and I am now at 5.9 pH.
10:15: Time for bed, so it had to be done pressing. Last pH measurement 5.7, weight 2# 2oz. Into the brine for 7 hours.
Next evening weight 1# 14oz
So my main question is regarding the pH... Should it have been so slow to drop? In comparison to Anut's recent posting on Jarlsberg, this seemed very slow.
Next question... If the meter was accurate, what can I expect with this cheese given the pH at into brine?
Susan
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When you wash the curd your removing lactose which slows down the acidification process. You have also diluted the whey so the pH goes up. I may have removed less whey than you? Also, the meter you are using will act funny when you are in between two pH values. It will go back and forth a bit. When my goes say from 6.5 to 6.4 and back, I assume that I'm just verging on 6.4, but not quite there yet. Your pH values do seem high through out the make, but I have only made this once and have no basis for comparison. Hopefully a more experienced cheese maker can answer that question for you. Your final pH and your cheeses weight were fine, so I wouldn't worry. Not to be an alarmist, but my first two meters got really erratic just before they quit working all together. You might want to start your makes earlier if at all possible, and you might want to play with your meter on different liquids of known pH until you're sure it is working correctly, before your next make. It's difficult when you first start making cheese to know if the problem is you, the recipe, or your cultures & equipment! :)
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Thermo cultures generally have a longer pH curve than mesos, especially if the thermos are not at optimum temperatures (yours seemed fine). I find that things start to speed up around the 4th hour and can drop like a rock at 5. You can always add a little basic meso to move the acidity along a little faster, but slow acidification is not a bad thing. For a variety of reasons, it's very possible that you needed to add more culture in the beginning. This again shows why you can't blindly follow a time based recipe.
That being said, I would also check your meter. Calibrate and try again. Your meter should have at least a 2 point calibration, 3 is better. If yours only calibrates to 1 point, it is not trustworthy.
So did you take the cheese out of the press at 10:15? If so, why? Thermos build up acidity in the press, so you generally want to press overnight.
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Thermos build up acidity in the press, so you generally want to press overnight.
Wouldn't you run the risk of overacidifying by keeping it in the press overnight? If it starts to build up acidity in the press, it seems like it would turn into a runaway by morning.
-Boofer-
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Boof, depends on where you hit the points in the acidity curve. It is vital for paste development to not go below 5.2 before brining. Ideally for most cheeses, 5.3-5.4.
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I did take it out of the press and into the brine because I was concerned that it would drop too low overnight, and I have been frustrated by cheeses that were apparently overacidified. Before I had the pH meter, I was routinely leaving the cheese in the press overnight, and ending up with a dry and crumbly paste.
So what will be the outcome if the acid level doesn't drop low enough?
And why is slow acidification "not a bad thing"? Does that mean it is a good thing?
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LB- what happens to the paste below PH 5.2 that makes point so important to paste development? I just put a Caerphilly into the brine and the PH at that point was 5.14. I do know that my pressing room was a little warmer than usual so I am sure that it pushed the development a little further along than what I normally would see.
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what happens to the paste below PH 5.2 that makes point so important to paste development?
Let's consider what's happening. From the onset, when acidity develops, casein micelles lose charges as the acid acts on them. So, you fuse them together to form a curd, creates a new dynamic of acid working on the colloidal calcium bonds inside micelles (as opposed to colloidal + k-casein for milk). Past 5.2, there is a tipping point. In milk, this is the point where you might see the earliest inclinations of some coagulation, a sort of thickness. In cheese, this is the point where too many sites become protonated.. that is, when acid degrades too many sites for sodium ions to bond properly.
End result, not enough balance between sodium and hydrogen ions, creates salt gradients due to poor sodium exchange, creates paste defects... often cheese brittleness, crumblyness, lack of cohesion.
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So what will be the outcome if the acid level doesn't drop low enough?
Residual lactose, often leading to post-acidification, which results in paste defects.
And why is slow acidification "not a bad thing"? Does that mean it is a good thing?
Because slowness results in more even calcium breakdown. Usually, any kind of gradient is an enemy. Salt gradients (except in blues), moisture gradients, pH gradients, etc are all undesireable. Slower but constant reaction produces superior results. This applies to cooking too, mostly... hence, sous vide works so well.
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This is exactly why I (and maybe LB) am often reluctant to talk about pH "points". Home cheesemakers setups and situations are all different and produce different results. If your pressing room is indeed too warm, your cheese will become more acidic than if it were pressed in a cooler room. So you have to compensate for that somehow. LB actually helped me think that thru last Fall. I was hitting all of my pH "markers" but some of my cheeses were becoming a little too acidic and crumbly. So, I now add less starter bacteria to slow things down, and I have adjusted my markers upwards to compensate for my conditions. So on a given cheese, if I was hooping at 5.8 and ending up at 5.0 after pressing, now I am hooping at 6.1 and ending up at 5.3. HUGE difference in my cheeses now. The important point is developing a system that works and can be replicated.
Air drying at room temperature for 2 or 3 days presents another opportunity for bacteria at warmer temperatures to be much more active. I take mine out of the press and immediately go into 54F for drying. That is also true of brining. If the brine is warm, bacteria will be much more active. I brine at 54F.
Bare in mind that the rules change with both a salted curd or a washed curd cheese. With a salted curd like cheddar, you have to get the curds down to near a finished pH BEFORE salting. The salt puts the breaks on the bacteria and seriously slows acid production. So, properly produced salted curd cheeses will not over acidify.
With a washed curd cheese you remove about 1/3 of the lactose so the bacteria simply can not over acidify. There's just not enough food to create a finished cheese with a low pH. That was the case with your Jarlsberg. Who knows what the pH really was, but it could NOT have gotten too low if you did a good job washing.
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I try to talk about 2 aspects
1) Ph "tipping points", which are pH at rennet, at drain/curd fuse (curd fuse is most accurate), and pH at salt/brine.
2) Balancing colloidal and non-colloidal calcium by understanding degree of calcium breakdown (micellar and to a degree, k-casein) in milk before rennet addition, and through brining.
In this regard, there are some absolutes. For example, draining below 5.8 is just about impossible practically. Ideally, curd fuse should happen at the degree of target calcium for the style. Higher (6.3-6.4) for alpines and parm, lower for continentals (6.2-6.3) and milled curd (6.0-6.15). There are also absolutes for brining, as I mentioned. But beyond that, there is a rather wide range possible when you balance the three tipping points together. And then you can modify screw ups through temp and curd washing.
The rest is pretty much useless. I can use pH points that are .2-.3 different, use a different culture, and produce an almost identical cheese to someone else. This is why it is vital to understand what your culture is doing, and focus on one cheese family and combination at a time until you fine tune the acidity curve with time and your practices and get into a make rhythm.
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LB,
In searching, I have found your use of the term "curd fuse" several times. At what point in the process does "curd fuse" happen, and what does it look like?
I just realized that I have now made 20 cheeses with rennet! So I am trying to look for patterns in the process and better understanding. On the most recent cheeses I have made, it seems like there is a point when the curds really want to knit together and have to really be stirred to keep that from happening. At the same time, if left to settle a bit they really want to clump. At the same time, they seem to be a bit squeaky when tasted. This was true with the manchego, gouda, and jarlsberg. Does this characteristic mean something?
Susan
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I think I'm the only one who uses that term. Everyone else uses the less precise definition of whey drain or hooping. For practical purposes, they're about the same, but I try to be exact in my descriptions. What you are most interested in is that precise point when individual curd bits gather together into a curd mass. When the pieces fuse together, even if it is a weak fuse. If you look at my recipes, I am a strong advocate of pre-pressing and matting curds under whey to achieve knit and even texture and reduce gradients in cheese.
The characteristic you describe is a sensory description for what happens when the acidity has developed enough to allow for some intra-micellar bond breakage, and therefore, a good degree of reorganization and re-bonding in curds. This is the earliest point at which you should try and fuse curds together. As acidity continues to develop, the fuse-ability slowly decreases due to fewer calcium sites available.
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I agree with LB. I almost always gather the curd in the whey and into the mold and press in the vat or pot at least under I have flipped a few times then just in the pot. For me it has always just given me better looking cheese wheels - LB knew the science behind why I was doing it.
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Boof, depends on where you hit the points in the acidity curve. It is vital for paste development to not go below 5.2 before brining. Ideally for most cheeses, 5.3-5.4.
At 9:00PM she had 5.9. A little over an hour later it had dropped .2 to 5.7. If you project that out over the next several hours (being mindful that the bacteria population is growing and contributing acid at an increasing rate), it seems quite reasonable that she would have been well into the red zone when she got up.
I was hitting all of my pH "markers" but some of my cheeses were becoming a little too acidic and crumbly. So, I now add less starter bacteria to slow things down, and I have adjusted my markers upwards to compensate for my conditions. So on a given cheese, if I was hooping at 5.8 and ending up at 5.0 after pressing, now I am hooping at 6.1 and ending up at 5.3. HUGE difference in my cheeses now. The important point is developing a system that works and can be replicated.
This is a good thing to remember and to adjust accordingly instead of being hung up on using set pH points. I have begun to move slightly off the selected target pH in order to more closely hit the end zone pH markers as LB framed:
1) Ph "tipping points", which are pH at rennet, at drain/curd fuse (curd fuse is most accurate), and pH at salt/brine.
Good dialogue about this.
-Boofer-
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Boof - you can't project a straight line for pH. As the bacteria start to produce more acid, they succumb to their own waste products (acid) and slow down. Every species/strain has a pH curve and a bottom end limit. For example according to Danisco, the TA50 series of S. thermo will not drop below about 5.25.
This is when it helps to have a flat electrode pH meter to measure the finished cheese as it comes out of the press. If it's too low there are many things that you can adjust for next time.
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Sailor, could you tell me what brand of pH meter you are talking about?
Also, are the pH curves and bottom end limit usually mentioned on the sites for the companies making the cultures?
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Boof - you can't project a straight line for pH. As the bacteria start to produce more acid, they succumb to their own waste products (acid) and slow down. Every species/strain has a pH curve and a bottom end limit. For example according to Danisco, the TA50 series of S. thermo will not drop below about 5.25.
This is when it helps to have a flat electrode pH meter to measure the finished cheese as it comes out of the press. If it's too low there are many things that you can adjust for next time.
I wasn't aware of these things. Good to know.
If the pH does happen to fall too low, measured coming off the press, what could be possible courses of correction for the next make (assuming the same cheese style/recipe)?
Reading my Danisco Alp D sheet I see that I can anticipate pH 4.5 after 7 hours. That presumes the dosage is correct for the acidity curve. That puts me in the red zone, no? The only way to be sure, that I can see, is to monitor the pH and don't go to bed while pressing is still active. Overnight pressing might work for a larger volume of cheese, but for small scale production (2-8 gallons) I would think close monitoring would be recommended.
Sailor, could you tell me what brand of pH meter you are talking about?
A lot of Extech ExStik PH100 (http://www.extech.com/instruments/product.asp?catid=69&prodid=430) or PH110 (http://www.extech.com/instruments/product.asp?catid=69&prodid=431) meters are in use on the forum. Meters with a flat surface electrode for fast and easy on-the-spot pH measurements.
-Boofer-
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Reduce starter bacteria, reduce ripening time, alter cooking temp a little, stir more (eliminates excess curd whey), drain & hoop a little early, do a partial curd wash. Depends on the cheese and what you are trying to achieve. When you drain, you are removing a huge amount of lactose and are putting the brakes on acid production at that point in the make. However as LB has pointed out many times, the acidity at draining is very important so you don't want to drain too early either. Pressing removes more whey and lactose and limits acid production even more.
The fallacy of pH points is that they are absolutes at every step of the make. If you are producing cheese every day on a commercial basis, that is true to a certain degree, but it is still about defining a method and routine that works within a given environment. Milk, cheese, bacteria, molds, are all living things not a mathematical equation that can be followed without subjective evaluation.
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Overnight pressing might work for a larger volume of cheese, but for small scale production (2-8 gallons) I would think close monitoring would be recommended.
Be careful. Danisco's Alp D relies on a synergistic (faster) acid production meant for a normal factory make. It's not like real alpine starter. Unless you have your dosages right and know how it behaves predictably, you have to monitor that drop to time your brine. Good part is that unlike emmethaler, an alpine type like alpkase or even gruyere will do alright even at 5.1-5.2 due to the very high drain pH. Not ideal, but with enough aging it will be OK. In a jarlsberger, with a wash, it's a decent fit because the wash helps to mitigate the drop.
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Okay, Sailor, that's good confirmation for what I've been following. Just checking to see if there was something I was missing.
-Boofer-