Pipette, Dairy

Quick Answer: A dairy pipette is a glass pipette used in milk testing to measure a set volume of milk, or of a reagent, into a butyrometer for the Gerber fat test. It is used in dairy plants, milk collection centres and dairy technology laboratories.

The Gerber Test and Its Pipettes

The Gerber method, developed by the Swiss chemist Niklaus Gerber in the 1890s, remains a routine way of measuring the fat content of milk. Concentrated sulfuric acid of a specified strength is placed in a butyrometer, a measured volume of milk is added from a pipette, followed by a little amyl alcohol. The acid dissolves the proteins surrounding the fat globules, the butyrometer is spun in a centrifuge and warmed in a water bath, and the released fat rises into the graduated stem, where its percentage is read directly.

Because the butyrometer scale assumes a fixed quantity of milk, the milk pipette is central to accuracy. In the Gerber method as widely practised the milk pipette delivers 10.75 ml, although some older and national procedures use 11 ml, and the acid and amyl alcohol are dispensed by separate pipettes or automatic measures. The listing is titled simply Pipette, Dairy, and does not say which of these it is or its volume, so name the method you follow when ordering.

Milk pipettes are usually of the one-mark type, so the technique follows that of a volumetric pipette: fill above the mark with a pipette filler, let the level fall to the mark, and deliver against the inner wall of the butyrometer neck.

Applications

• Routine fat testing of milk at dairy plants and milk collection centres
• Dairy technology and food science practicals on milk composition
• Quality checks on standardised, toned and skimmed milk
• Testing at collection points where payment to farmers depends on fat content

Specifications

Care & Handling

• Mix the milk sample gently but thoroughly before drawing it up, so the fat is evenly distributed.
• Use a pipette filler for every liquid, and never draw sulfuric acid by mouth.
• Rinse first with cold or lukewarm water, since hot water sets milk proteins on the glass, then wash with detergent and rinse with distilled water.
• Discard pipettes with chipped tips, which deliver inaccurate volumes.

Why Choose LabEquip

Dairy cooperatives, milk testing laboratories and dairy technology colleges buy dairy pipettes alongside butyrometers for routine Gerber testing. LabEquip lists them in its chemistry lab equipment; state your test method and the volume required on the contact page.

Frequently Asked Questions

Why must the pipette volume match the method exactly?

The butyrometer is graduated for a fixed quantity of milk, so the pipette volume is set by the method rather than chosen for convenience. A pipette of a different volume makes every reading on that scale wrong.

Can one pipette be used for milk and acid?

No. Keep separate pipettes or measures for milk, sulfuric acid and amyl alcohol. Acid left in a milk pipette would curdle the next sample, and milk residue in an acid measure affects the volume delivered.

Why must the milk be at a set temperature before pipetting?

Fat distribution and milk volume both change with temperature. Methods ask for the sample to be warmed, mixed and brought to a stated temperature so that the pipette delivers a consistent quantity and the fat is evenly dispersed.

How should the milk be delivered into the butyrometer?

Hold the pipette against the inside of the butyrometer neck and let the milk run gently down onto the acid, so that it forms a layer on top rather than mixing and charring at once. Let the pipette drain for the time set by the method.

How do I clean dairy pipettes?

Rinse them first in cold or lukewarm water to remove milk before it dries, since hot water sets the proteins. Then wash with a warm detergent solution, rinse with tap water and finish with distilled water.

Is the Gerber method the same as the Babcock test?

Both measure milk fat by dissolving the proteins with sulfuric acid and centrifuging, but they use different glassware, volumes and reading scales. Gerber adds amyl alcohol and reads in a butyrometer; Babcock uses a Babcock bottle and is more common in North America.

Last Updated: September 2026