cRystAllIZERs AND cApAcIty
Next up, we took a closer look at the effect of crystallizers on
production capacity. Fig. 2 shows the results of testing a similar
puff pastry margarine recipe to that used in our other trials.
We tested two production capacity levels, each with and
without crystallizers added. In Fig. 2, the pilot plant’s bar pressure
indicates that crystallization is occurring. When producing at low
capacity (40%), the fat has time to crystallize by itself. But at higher
capacity (above 70%), low bar pressure shows the fat is more liquid
and crystallization is less effective.
At low capacity, fast-crystallizing fat types can produce crystallization, but it requires crystallizers to be added to increase contact and result in sufficient crystallization both at higher and lower
As a general conclusion, it seems that the more crystallizers
you add, the higher the bar pressure and therefore the better you
can maintain or increase capacity. Without adding crystallizers, you
would need to reduce capacity, allowing the blend to remain in the
tube chillers for longer. So, while adding crystallizers will increase
recipe costs, there’s a worthwhile trade-off in better utilization of
Still in our experimental corner, we decided to look more
closely at the effect of different crystallizer dosages on production
capacity, moving from zero to 0.5%, 1%, 1.5%, and, finally, right up
to 2%. To make things more interesting, we simultaneously tested
the effect of two different rotation speeds: 400 and 800 rpm
In Figs. 3 and 4, the colored bars represent the four tube
chillers in our pilot lab production setup. It came as no surprise,
of course, that the viscosity needed for margarine required
more energy toward the end of the production line. We also
confirmed that applying crystallizers does indeed increase
viscosity by the end of the process, but the difference they
make is nothing extraordinary.
FIG. 2. The effect of crystallizer doses on production capacity
cRystAllIZERs AND pUFF pAstRy
Margarine produced for incorporation into puff pastry is very
thin when first made, expanding in the oven to arrive at the
mouth-feel loved by consumers all over the world. Seen from a
puff pastry expansion point of view, trials with Palsgaard’s crystallizers produce a very stable margarine. No matter how hard
we work the product, it still performs well in this vital regard.
But we were curious to learn what might happen if we were to
conduct a baking test on the final product itself. So we measured the effect on ten such pastries of increasing crystallizer
dosages from zero to 2%, switching between three different
Normally, rotation speed isn’t a parameter most production staff can work with. Often, that’s because most production machinery has a fixed speed—or enables switching only
between one or two levels. Now however, in a trans-fat-free
landscape, the ability to adjust rotation speed in combination
with various dosages of crystallizers has become a key factor
for achieving the right result.
In Fig. 5, rotation speed strongly affects expansion results,
performing best at around 11 rpm. Introducing crystallizers
smooths out the effects of rotation speeds, enabling a good
expansion result not only with different process parameters
but also on different machines—expansion simply becomes less
sensitive to process parameter variations. There is, of course,
production machinery that can arrive at comparable results
without any addition of crystallizers, but few manufacturers
have invested in the up-to-date equipment that can do it.
ARE cRystAllIZERs AWAys NEcEssARy?
It is possible to create recipes that perform just as well as—or
at least comparably—to the performance of a trans-fat-containing formulation. For example, cake margarines that use
fast-crystallizing fat types such as palm oil or coconut oil fat
have nothing to be gained by adding crystallizers. But with
cheaper fat types, small amounts of crystallizers can make a
However, in replacing trans, there is no way to avoid
spending some amount of additional funds—and, for most, the
costs will be high. Manufacturers will need to take a look at
their equipment line-up. Most likely, older machinery won’t be
enough to maintain current capacity and product quality on the
new, trans-fat-free playing field—not without applying crystallizer dosages as high as 2%.