Surface crack type defects of cheese can be many and are cheese type dependent. This article explores the common surface crack defects, their common causes and solutions, sorted by root problem. But first the description.
- Single or multiple cracks in surface of pressed cheese ranging from small to large fissure depending on severity.
- Unknown in unpressed cheeses.
- Most common is drying a natural rind of a pressed cheese in an aging environment’s where the humidity is far too low. Common examples are in post pressing air drying phase or if trying to age in a very low humidity environment such as uncovered in a cold household forced air style fridge. The rapid dehydration of the cheese results in rapid shrinkage of exterior, but not interior of cheese resulting in high tensile stress in surface of cheese and compression of interior of cheese somewhat like a football but to lower extent. As cheese has lower tensile than compressive strength, the cheese surface eventually tears or cracks to partially relieve the stress. The cracks become progressively larger if humidity is not corrected. High moisture content fresh pressed cheeses such as washed curd Gouda’s are more susceptable to this than low moisture content fresh pressed cheeses such as Parmesan due to the higher possible moisture content differential between surface and interior.
- The short term solution is not to seal i.e. by waxing but to reasonably heal the cracks. This is done by minimizing further dehydration and enabling the moisture content of the cheese to re-equalize between surface and middle to relieve the stress within the cheese enabling the crack(s) to mostly heal. This can be done by placing the cheese in a high humidity environment, an example are placing on a mat on a board or plate and placing a lid such a bowl over top to mostly seal the humidity in. Normally the cheese will still be giving off enough moisture that providing extra humidity from a bowl of water etc is not required. Note, during this healing period ensure that humidity is not 100%, i.e. condensation, puddling of water, otherwise normally unwanted surface molds will be activated. Another additional option is to semi-seal the exterior of the cheese but not the internal cracks by rubbing exterior with oil which will develop a firm not soft or sticky rind.
- The longer term solution is, for future cheese making, to develop a better humidity control system.
Curds Too Cold
- If making cheddared (stacked and milled) type cheese, curds may have become too cold causing uneven texture.
- Short term solution is if cheese is straight out of press, to repair cracks, seal the cheese in 65C / 150F water for 1 minute.
- Longer term solution is, for future cheese making, to ensure stacked curds are kept warm.
Brine Too Acidic
- If making cheeses that require a brine bath such as Washed Curd type cheeses (i.e. Gouda, Edam), if brine is too acidic, the bathing cheese will have a pH shock which can result it small series of cracks all over rind.
- Short term solution is to remove cheese from brine, let air dry in high humidity environment as described above, then when cracks reasonably healed, continue brining with pH adjusted to ideal 5.5-5.6.
- Longer term solution is, for future cheese making, ensure brine pH is in optimal range.
- Pressing cheeses is often performed using a cheese cloth sheet lined hoop to hold the soft curds during pressing. Folds in cloth due to using sheet in shape of cylinder result in indented grooves or “wrinkles” in pressed cheese. This problem is more prnouced in small versus larger cheeses due to geometry.
- First, ensure cloth is thin, not thick to minimize indent grooves.
- Second, during initial light pressing’s, cloth should be pulled vertically straight up around perimeter while holding follower down to ensure cloth is vertical and minimal around cheese or alternatively, sew cloth into a cylinder shape to match size of hoop to reduce excess cloth around periphery, use with seams facing outward.
- Third, after initial pressings, curds should have started to knit, for subsequent heavier pressings, remove the cloth liner.
- In pressed cheeses, if the curd wasn’t fully knit during pressing, subsequent drying can cause shallow cracks all over the surface of the cheese. One cause of poor knitting is under-pressing.
- Pressed type cheeses during and after pressing are commonly still moist and heavy with little tensile strength. Improper handling such as pinching /squeezing around periphery to lift the cheese can result in closed cracks in surface of cheese.
- Lift cheeses from bottom as they are much stronger in compression from their own weight than in tension.