The ASBC Beer Color scale has a range of approximately 1 to 11 units, with the more yellow, pale worts at the low end of the scale and the redder color of dark worts, beers and caramels at the upper end of the scale.
The industry reference method for ASBC Beer Color and Turbidity Is:
ASBC Beer-10 Color of Beer Part A. Spectrophotometric Color Method available from ASBC – American Society of Brewing Chemists, affiliated with AACC – American Association of Cereal Chemists, St. Paul, MN USA www.scisoc.org/aacc. Continue reading →
FAQ: “I have worked with a company measuring the color of sports drinks. Now this company is interested in fruit drinks and also in carbonated soft drinks. Have you worked with these types of beverages? Any advice or recommendations?”
Fruit drinks contain:
may contain some fruit juice or fruit solids
flavors (oil emulsions)
may have clouding agent which is usually citric acid. Putting in a clouding agent to create a hazy appearance is a marketing decision which depends on the consumer association with the type of drink.
In a fruit drink, whether there is any natural fruit juice or not, the appearance of haze can be created by the presence of oil flavor emulsions and/or clouding agents such as citric acid. These are added on purpose to create a hazy appearance in some flavors of fruit drinks such as pineapple, lemonade, grapefruit and guava where the consumer expects some scattering.
For other fruit drink flavors such as apple, cream soda or grape the consumer does not have the expectation of a hazy appearance and no additional clouding agents are added.HunterLab can measure both lot-to-lot color and haze (or no haze for clear drinks) inherent in different fruit drinks.
If the beverage is carbonated (a separate source of scattering), it should be decarbonated to remove the carbonation as an unnecessary cause of scattering (independent of color) and measurement variation.To de-carbonate the beverage, place the liquid sample in a sonicator (there are a number available but I have seen a Branson Sonicator in successful use in the lab) that breaks up the carbonization by bombarding with Ultrasound for 60 seconds. Some care has to be taken that the carbonated beverage be placed in a container at least twice the volume of the beverage because when the ultrasound pummels the carbonization, the release of carbon dioxide gas can effervesce suddenly.
Another low-tech option to decarbonization is to place an air hose from the normal lab air supply into the beverage and gently run the air for about 4 minutes. The slow stream of air bubbles break up the carbonization gradually.
The current, available ASTM D1003 Haze Standards have nominal Haze% values of 1, 5, 10, 20 and 30 with air (transparent solids) or the transmission cell filled with DI water being 0 (transparent liquids). Here are some thoughts on further options. Continue reading →
FAQ: “We take the results from the Didymium Filter Test on our HunterLab ColorQuest XT and plot them in an SPC chart over time to look at trends. We are seeing the 430 and 570 nm filters slowly decrease. Can you help us understand what may be occurring?”Continue reading →
HunterLab diffuse sphere instruments are often used to measure liquid samples, especially clear liquids. The liquid fragrance shown above is one such example of a clear liquid. The fragrances is so clear that is resembles water.
Fragrances such as this are often added to cleaning supplies, air fresheners, or other consumer products. One of the problems that this type of sample can experience is that the chemistry of the liquid fragrance solution can deteriorate and the solution will start to visually yellow. This is often a concern for manufactures because if the liquid fragrance yellows it cannot be added to the end product.
HunterLab sphere instruments can measure the transmitted color of the liquid and report the yellowness index. The liquid fragrance should be measured in a 20mm path length cell. Since the sample is very clear, near water in color, this slightly larger path length allows for the light to pass through more of the sample. This measurement method ensures that smaller differences can be measured between samples.
With the proper instrument and the appropriate accessories from HunterLab, very clear liquid samples can be accurately and repeatedly measured for color consistency.
FAQ: “We have a scientist here who is looking at films containing small bubbles and attempting to do measure them by measuring Haze% on a HunterLab spectrophotometer. I suspect her problem in obtaining numbers that “make sense” from what you get from just eyeballing the samples (and trying to look through them at the outlines of a object behind the film to gage the amount of regular transmittance) is that her samples have Haze% > 30 %, which means that a spectrophotometer (or even a haze meter) isn’t the appropriate tool to use for the analysis.
How is transmission haze measured at levels > 30%?”