We have all seen recipes which call for you to perform a "Grip Test" towards the end of the cooking of the curds, at whatever is the highest temperature they reach.... That could be from direct heating, or using a warm water wash, which is usually followed by a period of stirring until they "feel" right.... Understanding that correct feel, in its various and subtle variations, is obviously the way the old-time cheesemakers did the job, before the day of pH meters.... so it would be helpful if those of you with a lot more experience than I could give us noobs their advice on how the Grip Test might relate to the pH....
I have been doing Grip Tests on every cheese I make for several months now, whether the recipe calls for it or not (I don't own a pH meter, and have no desire to get one).... In addition, every time I see one mentioned in a recipe, I try and visualize and understand what they are describing.... I have come up with a "scale" from soft to hard, that goes something like this.... Note, we only do Semi-Soft to Extra-Hard cheeses that are pressed in a mold....
1. Very Soft.... When you squeeze a small ball of curds in your hand, they turn to mush, and milky whey runs out between your fingers....
2. Soft.... The ball of curds compresses into a soft mass, with the curds melding together easily, and when teased with the thumb, tend to stay matted.... Individual curds, when pinched between the index finger and thumb flatten and tend not to rebound....
3. Medium Soft.... The ball of curds consolidates, but you can still see individual curds, and when teased with the thumb the ball starts to come apart.... Individual curds are a bit resilient, and bounce back to about half their original thickness after pinching....
4. Medium.... The ball of curds sticks together, but the curds come apart quite easily when teased with the thumb.... Individual curds are quite resilient, and return almost to their original shape after pinching....
5. Medium Firm.... The ball of curds still sticks together a bit, but falls apart when touched with the thumb.... Individual curds are quite firm, returning to their original shape after pinching....
6. Firm.... The ball of curds barely sticks together, and often breaks just when you open your hand.... Individual curds are definitely springy, offering significant resistance when pinched....
7. Very Firm.... I haven't experienced this (yet), but would expect this to be what Peter Dixon calls curds that will "bounce"....
Most recipes seem to want the curds to be about level 4. Medium, or so my limited experience indicates.... When I stop before this, I find the moisture quite high, and the cheese looses a lot of whey when pressed.... I can't remember the last time I stopped cooking the curds before they reached level 3. Medium Soft.... as below that the cheese has a tendency to slump.... Yesterday we made a Colby, where the recipe called for stirring the curds at 102*F for 60-90 min. until they were "springy".... I kept track of what the Grip was like, starting at 30 min, at which point they were "Soft".... At 45 min. they were "Medium Soft", and a 60 min. they were "Medium".... For most recipes, I would have stopped cooking at that point.... By the time 75 min. had gone by they were at the "Medium Firm" stage, and I stirred them for the full 90 min. before individual curds were what I considered "springy", which I describe above as "Firm".... At that point, the curds were partially drained and washed with cold water, stirred for 15 min. then partially drained and stirred at 86*F for 30 min. before pressing.... After 15 min. at 10 lbs. they were barely hanging together enough to flip the cheese, but after another 30 min. at 20 lbs. were well consolidated (though still soft), with only a few cracks in the rind.... After another hour at 40 lbs. the rind was completely closed, and very little whey was expressed on that cycle.... After pressing at 80+ lbs. (3.5 psi) overnight, only a further teaspoon of whey was released, and the cheese is quite firm....
This was the first time I had tried to produce "springy" curds, other than by cheddaring.... It was interesting and informative to see how the curds changed as they were cooked longer.... I will definitely be recording the results of my Grip Tests, using the scale above, for all future makes.... but I was wondering if there is any correlation to the pH in any significant and repeatable manner that could be quantified.... While the moisture content obviously decreases with cooking time (and temperature), it is also related to the curd size, determined by the Flocculation time and curd cutting.... Is the "Grip Test" only related to the moisture, or, for example would larger curds, cooked longer have a higher or lower pH than smaller curds cooked shorter, but with a similar Grip?.... Any comments from those more experienced amongst you will be most welcome....
Bob
