easily provable in a laboratory. The more interesting
question to me was, are the effects of the minerals in the
water (referred to as Total Dissolved Solids, or TDS)
significant enough to be detected by a normal eater in a real-
world situation?
To answer the question, I charged Mathieu with making
Neapolitan pizzas using waters with different TDS contents
and brought in a panel of pizza experts to taste the finished
pies. The problem is that the real world is, well, real, and as
such, very difficult to control. In any scientific endeavor,
there are a number of key principles that must be adhered to
if you want to ensure that your results are accurate and
repeatable—the hallmark of any sound experiment.
Key to a Good Tasting #1: Eliminate Bias
Despite our best efforts, we have yet to invent a device that
empirically measures precisely how delicious pizza crust is,
so our best option is to resort to the crude analyses of our
mouths. Humans are notoriously bad at separating
emotional responses to foods and food brands from their
actual eating qualities, and the only way to eliminate this
bias is with a double-blind tasting—a tasting in which
neither the tasters nor the people preparing and serving the
food know which sample is which.
To do that, I first gathered my waters—five different
varieties of bottled waters with TDS contents ranging from
less than 10 ppm (the maximum allowable for “purified”
waters) all the way up to 370 ppm (mineral water on the
high end of the TDS scale), along with tap water. I chose the
specific brands because they were available at my local