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Beer and wort color traditionally have been measured
visually, and early on the Lovibond (degL) scale was adopted as a
standard. This scale consists of a well-defined set of color samples that
are used for comparison. A visual match with a beer or wort sample defines
the degL of the sample.
In 1958, the American Society of Brewing Chemists proposed a
more scientific means of measuring color using wavelength and light
absorption measurements; the procedure was called the Standard Reference
Method (SRM). They proposed a correction factor of 10 so the numbers
reported would match up with the Lovibond scale
So now you know what it looks like... how do you make it?
Here is are the general color properties of a selection of grains.
| Malt Type |
Color degL |
| U.S. two-row |
1.4 - 1 8 |
| U.S. six-row |
1.5 - 1.9 |
| Canadian two-row |
1.3 - 1.7 |
| Canadian six-row |
1.4 - 1.9 |
| German Pils (two-row) |
1.6 |
| German lager (two-row) |
1.7 |
| CaraPils |
1.3 - 1.8 |
| Wheat malt |
1.6 - 1.8 |
| Pale ale |
3 |
| Vienna |
3 - 5 |
| Light Munich |
8 - 11 |
| Dark Munich |
18 - 22 |
| Caramel |
10 - 120 |
| Chocolate malt |
325 - 375 |
| Black |
475 - 525 |
| Black barley |
500 - 550 |
As a rule of thumb the color contributed by a malt is equal to its
concentration in pounds per gallon times its color rating in degL.
For lighter colored beers this rule works reasonably well. For
example, 10 pounds of pale malt with color 1.6 degL in five gallons should
produce a beer whose color is near
1.6 x 10/5 = 3.2degL.
For darker beers you may experience more erratic results.
Also keep in mind that differences in a number of brewing conditions
can lead to substantial color changes in the finished beer, these effects
being particularly important for beers at 5 degL or less.
- Water: As the alkalinity of the water increases, so does the
extraction rate of the coloring pigments in malt. The mash pH has the
same effect, and increasing pH leads to worts with deeper color.
- Mash or Steep Time: Color increases with the amount of contact time
with the grains. Thus, a prolonged mash (or steep) will produce a
deeper-colored beer than a short mash.
- Kettle Boil Time: Wort color increases with boil time. A fact that
is sometimes overlooked is that wort simmering has the same effect. The
point is that this will lead to an incomplete hot and cold break, which
in turn leaves more coloring elements in the finished wort.
- Hops: Some color is obtained from hops both in the kettle and in
storage containers when post-fermentation hopping is used.
- Fermentation: The proteinous matter produced during the cold break
is full of coloring materials and, hence, removal of these materials
will reduce color. It has also been reported that color changes during
fermentation vary with yeast strain.
- Filtration: This can dramatically reduce color. It should be noted
that a clear beer will appear to be lighter color than turbid
beer.
- Oxidation: At all stages of brewing, air pickup will deepen beer
color. This is as true of hot wort production as it is of bottled beer
with head-space air.
Information courtesy of Wrucksterbräu | 