Cameron Winery -- sustainably farmed, non-irrigated, Oregon pinot noir and chardonnay

The Elements of Pizza by Ken Forkish

Measuring Brix isn’t just important for winemaking.   The consistency and quality of premium canned tomatoes (such as San Marzano) relies on careful measurement of the Brix of  tomatoes at harvest (to determine ripeness) and in the final product (to determine sweetness and thickness).  Here we proudly present “What’s a Brix?”, written by my wife Teri, and featured on page 67 Ken Forkish’s fabulous new book, The Elements of Pizza.

The Brix scale is named after 19th-century German scientist Adolf Brix, who invented the hydrometer, an instrument that could measure the sugar content of grape juice for wine.  Before this, ripeness could only be determined subjectively, by taste.  The Brix scale can also be used to measure ripeness in the juice of other fruits, like tomatoes.

In winemaking, 1 degree Brix is equivalent to 1 g of soluble solids (the sum of sucrose, fructose, vitamins, proteins, and so on) per 100 g of grape juice.  In winemaking, an effort is made to harvest at a particular Brix level, and this measure of ripeness and its corresponding sugar content in the fruit directly relates to the fermentation potential in the wine, its flavor, and ultimately the conversion to alcohol.  In theory, alcohol is produced at a rate of approximately 51% of fermentable sugar.  Variables such as exposure to oxygen and temperature, the amount of yeast and yeast diversity determine the actual conversion rate from fermentable sugars to alcohol and carbon dioxide.

Tomatoes go through the same seasonal harvest variability as grapes and other fruits of the earth do.  There is a right time to harvest, and measuring Brix in tomatoes is as important to timing harvest as it is for grapes, when the desire is to produce canned tomatoes that have consistent flavor, acidity, texture and water content (think of it as thickness or thinness of tomato sauce from one can to the next, from one day to the next).  Fruit ripening involves a series of related and complex enzyme-catalyzed transformations.  When starches are converted into simple sugars by natural enzymes, the fruit sweetens.  A tomato changes from green to red as chlorophyll breaks down to reveal underlying pigmented compounds such as anthocyanins and lycopenes.  It becomes less tart as organic acids are converted into less acidic molecules; softer as pectin is broken down; and more fragrant as volatile aromatic compounds are synthesized.  Brix is an extremely useful objective marker for ripeness.