Never run out mid-test — these phenolphthalein indicator refills keep your acid testing set ready for the next batch.
Phenolphthalein is the colour-change indicator used in titration-based acid testing for home winemaking. As you add sodium hydroxide solution during the test, phenolphthalein triggers a clear pink colour change at the titration endpoint, allowing you to calculate titratable acidity (TA). These 20 ml refill bottles are sized for multiple testing sessions.
- Volume: 20 ml
- For use with standard acid testing sets
- Colour-change indicator for TA titration
- Multiple tests per bottle
Winemaker's Tip: A clear, stable pink colour (not hot pink) indicates the correct endpoint — adding too much NaOH overshoots it and gives a falsely high TA reading.
Part of the Acid Testing Set. Also see Sodium Hydroxide Refills.