Instruction manual
Page 37
Yogurt-Making Notes
Which Culture Should I Use? Our testing showed that store-bought
yogurts are not all created equal—some make dramatically better
starter cultures than others. While all the brands of plain “live culture”
supermarket yogurt will work, some produce thinner textures while others
are thicker, and a few produce yogurts that rm much more quickly than
others. Some are more susceptible to the lumpy texture that comes from
culturing too long or too hot. It’s worthwhile to test several different brands
of yogurt until you nd a favorite culture.
Does Boiling Before Culturing Ruin the Yogurt? No. The casein
proteins and whey proteins do not coagulate when heated unless acid is
also present, and the integrity of the fat in milk is actually strengthened by
boiling. To test this, we made yogurt from milk that had been simmered
long enough to reduce the volume by 25%. The result is a thick, smooth
creamy yogurt with the strongest “custard” taste of any of the yogurts we
tested. We didn’t choose this method for our custard-style yogurt because
the cooked milk/custard taste is so prominent that it starts to seem like
something other than yogurt. But it was a favorite among some of our
tasters, and it’s good to know that if you accidentally heat the milk hot
enough to produce a few bubbles, nothing bad will happen to your yogurt.
The Folding Proofer Consistently Makes Thick, Smooth Yogurt
Automatic yogurt makers operate on a pre-programmed, automatic cycle
which do not allow you to control results. With the Folding Proofer, you
can alter timing and temperature settings to produce yogurt to your taste.
Protein is Key to Thickening. The casein (protein) clusters in milk
thicken yogurt by unraveling and forming a three-dimensional mesh
when exposed to the lactic acid created by culturing. Heating milk above
172F/78C before culturing denatures one of the main whey proteins,
lactoglobulin, which allows it to join in the mesh (instead of remaining
inactive) and effectively increases the amount of protein in the milk
that will be available to thicken the yogurt. The reaction takes time, so
milk needs to be held at 195F/90C for ten minutes to denature most of
the lactoglobulin. A little evaporation during this heating also aids the
thickening benets of this procedure. When available, higher-protein
milks like Jersey or Guernsey make wonderful yogurt.
Culturing Temperature Affects Texture. In addition to the quantity
of protein available to form a mesh, the stability of that mesh is also
important, determined by the temperature at which the mesh forms. The