Rapid protocol
Why the pectin test matters
Juice clarification (static settling or flotation) requires a complete degradation of pectin. A negative pectin test indicates efficient viscosity reduction and good flocculation capacity, securing clean fermentation and reducing oxidation risks.
- Sample: grape juice / must
- Time required: ~10 minutes
- Purpose: check pectin degradation before clarification or flotation
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How to do the pectin test
1. Prepare the acidified alcohol solution
Ethanol 96% acidified with 1% concentrated hydrochloric acid.
2. Prepare the must to be tested
If the must is charged with solid particles, a coarse filtration on paper is recommended.
3. Add the solution to the must
In a test tube, gently mix (to avoid breaking the pectin gel) 2 volumes of the prepared solution of acidified alcohol with 1 volume of must.
How to interpret the results
Negative
Complete pectin hydrolysis
The solution remains clear after 10 minutes of reaction.
Positive
Low presence of pectin
When mixing, small bubbles are formed and slowly float upwards.
Positive
Presence of pectin
When mixing, big bubbles are formed and can’t easily move up.
Positive
High presence of pectin
Heavy bubbles and a ring of gel
appear on the surface of the liquid after 10 minutes of reaction.