Raisins, Part I

The more you ignore them, the drier they get.

Raisins.

Sweet, plump, and wrinkled, just how I like my wo--  Um, that is to say…

Raisins.

Sweet, plump, and wrinkled, raisins have been touted as nature’s candy for millennia.  They can be found in sweet applications, such as scones and cookies, or savory applications, such as pilafs and tagines.  As long as people have been leaving grapes out in the sun to shrivel, they have been finding delicious uses for the end result.

But what exactly is a raisin? 

One could ask the same thing about water.  What exactly is water?

We just don’t know.

What we do know is that, in the U.S., we are most familiar with two types of raisins: the brown ones, and the not brown ones.  One might assume that the brown raisins began their unsuspecting lives and red grapes, whilst the not brown raisins (for sake of simplicity, we shall henceforth refer to them as “golden” raisins) began as green grapes.  This would be a foolish assumption, based solely on ignorance, and is therefore unacceptable.  In a moment, we will come to the true origin of these raisin brothers from other mothers.

Let us first, however, bring another raisin name into play: the Sultana.  This is a term not widely used in the U.S., found mostly in Commonwealth nations as a strange remnant of British Imperialism.  When asked about the difference between Sultanas and raisins, a dear friend of mine from the motherland explained that “sultanas come from green grapes and raisins come from red grapes.”  Taking this explanation at face value would lead to the conclusion that “Sultana” is simply a different, some would say “more correct,” name for the golden raisin.  However, this conclusion, as well as the explanation about Sultanic origin, is grievously false.

As it turns out, raisins, golden raisins, and Sultanas are all the withered descendants of just one grape: good old Thompson Seedless.  Thompsons are green grapes no matter which way you look at them, and rarely as sweet as a raisin.  Bearing this in mind, the path from one grape to a triune raisinhood may be a difficult route to understand, but the reward is a head full of useless trivia and a fist full of dried fruit.

As a grape dries, a few things happen.  Primarily, it loses the mass and volume that the bit of moisture provided.  This affects not just the physical properties of the raisin, but the resulting flavor.

Raisins are sweeter than grapes because the proportion of sugar to moisture is much higher.  A teaspoon of sugar mixed with a teaspoon of water will taste sweeter than a teaspoon of sugar in a cup of water.  By this example, a raisin may be thought of as a concentrated grape.

A secondary effect of the drying process is that the grape undergoes oxidation.  This is the same process that causes things such as apples, avocados, potatoes and tea leaves to darken.  And so a green grape, dried and oxidized, becomes a brown raisin.

A "golden raisin" is simply a green grape that has been treated with sulfur dioxide, an anti-oxidant, to preserve its color.  Sulfur dioxide may sound nasty, but it is used in many dried fruits to retain color.  Think of dried apricots, for instance, or even sun dried tomatoes.  You can get sulfur free versions of both of these, but they will be brownish due to oxidation.

Some would say that oxidation affects the flavor of the fruit, those this could be disputed.  Certainly the raisin companies will say that a golden raisin has a different flavor profile than a brown raisin, but that may just be an excuse to double their product line.

So what's this "sultana" thing all about?  We shall come to this in due course, but first, join me in a few days for some raisin science.  Raiscience!