Bostwick Viscosity (Consistency) Measurement
Bostwick viscosity is a practical method for assessing the flow behavior or consistency of semi-liquid products by measuring how far they travel under their own weight over a fixed time. It’s not a true viscosity measurement (like centipoise) but a flow distance metric that correlates with product thickness and pourability.
Principle
- A sample is placed behind a spring-loaded gate in a Bostwick Consistometer, a stainless-steel trough with graduated markings (typically 0.5 cm increments).
- When the gate is released, the sample flows along the trough under gravity.
- The distance traveled in 30 seconds is recorded in centimeters.
- Shorter distance = thicker product; longer distance = thinner product.
Principle
- A sample is placed behind a spring-loaded gate in a Bostwick Consistometer, a stainless-steel trough with graduated markings (typically 0.5 cm increments).
- When the gate is released, the sample flows along the trough under gravity.
- The distance traveled in 30 seconds is recorded in centimeters.
- Shorter distance = thicker product; longer distance = thinner product.
Applications
- Tomato products: ketchup, paste, puree
- Sauces and dressings: mustard, mayonnaise, salad dressings
- Baby food, soups, gravies
- Fruit purees and jams
- Batter and dough formulations
- Paints, cosmetics, and personal care products
Advantages
- Simple, fast, and cost-effective
- Requires minimal training
- Useful for batch-to-batch consistency checks
- Ideal for QA/QC in production environments
Limitations
- Not a true viscosity value (not in centipoise or mPa·s)
- Not suitable for very thin (e.g., water) or very thick (e.g., dough) samples
- Results are not standardized across industries—used for internal benchmarks
Standards & References
- ASTM F1080-93 – Standard test method for consistency of sauces using Bostwick Consistometer
- USDA Tomato Products Specifications – Require Bostwick values for ketchup and paste
- AOAC Guidelines – Referenced in product-specific methods for sauces and condiments
Leading food testing laboratory ensuring safety and quality in the food industry.
Contact Us
9341 E.Childs Ave., Planada, CA 95365, USA.
operations@fsa-lab.com
info@fsa-lab.com
support@fsa-lab.com
Office 1 : (209) 877 8728 Office 2 : (209) 877 8729