I sent the questions to Danlac, were I get my stuff and got a reply today, here is the e-mail;
Questions as follows:
Several of us are having the same problem and was wondering if u can help.
1) sometimes when hard cheese are made they do not melt, why?
2) When making Swiss cheese, it starts to break up after a few hours in
brine, nice and pliable before hand.
we do not use meters so cant tell u the acid/PH.
Helpful hints from Dave Burley:
These problems relate to the total titrable acidity in the cheese and pH.
Not stopping the fermentation soon enough will cause these problems, as can
adding too much starter or having too high or low ( depending on the
starter) a cook temperature. What is happening is the cheese will not fuse
because the pH is too low. This sort of cheese will be hard in the mouth
and crumbly to the bite, like the grana cheeses of Italy. In my experience,
this is the most common fault of amateur and small dairy cheeses. It is
tricky to get this fusibility condition consistently without using pH
evaluations, as that is the condition which controls the calcium levels and
the state of the various caseins, esp the beta and gamma caseins.
In the old days before things like titration and pH meters, a technique of
the hot iron test was used to see if a melting cheese was ready to have the
fermentation stopped. The test was simple. A piece of iron, like a large
uncoated ( no zinc or chrome around food) nail, was heated to red heat and
stuck on a cheese curd surface and pulled, The length of the pull ( say 6-8
inches for cheddar, as I recall) was an indication of the meltability of the
cheese. Making Mozzarella and stretching it is likewise controlled by the pH
and temperature. A pH of not lower than 5.1 is desirable. Taking a sample
of curd and squeezing it in the palm of your hand is another crude way (
used even today) to evaluate curd fusability. Remember the various starters
have various proportions of mesophilic and thermophilic lactobacillus and
will respond to temperature differently. Raising the temperature of the cook
will slow down mesophilic ( cheddar type) bacteria and speed up the
thermophilic ( swiss and mozz ) bacteria up to a point. Many modern
starters have both types, so you need to do trials.
In the case of the cheddar, salting of the curd basically halts the pH drop
and the placing of the <<warm>> curd in the mold and holding it warm for a
few hours during pressing will guarantee curd fusion and a good toasted
cheese sandwich. Likewise with Swiss varieties it is important to sweep the
finely grained cheese curd from the kettle and pack it into the press
immediately and to keep it warm so it will have the opportunity to fuse.
Note in this case the fermentation will continue, so presss early. These,
when cooler in a few hours, can be brined safely. Brining too soon before
curd fusion or when the pH of the curd is too low to fuse will cause the
cheese to disintegrate in the brine. Make sure your brine pH and salinity
are correct. I suggest 18% -20% salinity - and egg will just float - and pH
to being of 5.0 adjusted with hydrochloric or preferably lactic acid from
sterilized whey allowed to ferment a few hours. Reuse your brine as it will
improve with use, but guard against bactgerial contamination, esp
Salmonella. Skim the brine after each use and periodically sterilize it by
heating it to 180F. Adjust the salinity before each use, as the salt content
will drop with use. Brine cheeses cool at 50-60F. Check in your library for
a copy of Adnan Tamime’s new book “Brined Cheeses”. pH at various points in
the process will be dependent on the milk source which depends on the time
of year as to buffer capacity, so you will have to vary your techniques
throughout the year, as the old timers did when using a single herd source.
Try this, reduce your starter concentration by a factor of two. Reduce your
cook time by say 10 minutes. Reduce or increase your cook temperature by
5-10 degrees. Do these separately on different batches to get into the
ballpark and then modify your procedures. If you do not have access to a pH
meter or reagents to titrate the cheese, get some narrow range pH paper in
the 4 to 6 range and use them to judge when to begin pressing. Keep your
presses warm. There is a reason for all those press cloths and wrapped
presses in the older cheese technology and for the size of the cheeses.
Helping to keep the temperature up during curd fusion. If you make small
cheeses, temperature control is highly problematic. Make good use of your
oven or an insulated box with a hot light to keep the temperature up. Be
sure to use a ceramic base for the bulb if it is on for long periods and
unattended.
Part 1