Diagnosis · Gel too soft — low pH hydrolysis
The acid is destroying the polymer before it ever sets
Below about pH 3.5 the glycosidic backbone hydrolyses, and the rate climbs steeply with temperature. Polymer dosed into a hot acidic batch loses a large part of its molecular weight before it meets a cation, so the finished gel behaves like a much lower dose.
What to do
- Hydrate and fully dissolve the gellan at 90–95 °C in the unacidified base. This step is not optional.
- Add the acid late, at the lowest temperature the process allows, and cool straight afterwards.
- Expect 20–30% more gellan than the same texture would need in a neutral system.
- Consider a blend with xanthan to recover some body without relying entirely on the gellan network.
The reading behind this
How this conclusion was reached
What is actually going wrong?
The gel is too soft, or will not set at all
Does the formula contain free calcium or magnesium — milk, mineral water, an added calcium salt, or hard tap water?
Yes, there is a clear divalent source
Are you using a high acyl grade?
No, low acyl
Is the finished pH below about 3.5?
Yes, it is a low pH system
Check this against your own system
This describes the usual cause. What actually fixes it depends on your water hardness, total solids and fill temperature — send those three numbers and we will come back with a starting point, or with a bench sample of the grade this points to.
Ask about this diagnosisOther conclusions
Everything else the tree can land on
- Gel too soft — no calcium present
- Gel too soft — water hardness unknown
- Gel too soft — high acyl grade
- Gel too soft — remaining causes
- Lumps — powder not dry blended
- Lumps — hydration window missed
- Lumps — process details to check
- Pre-gelation — in the line
- Pre-gelation — free calcium
- Pre-gelation — cold tank
- Syneresis — water weeping
- Gel cloudy or dull
- Gel melts when warm
- Particles settle
- Slimy mouthfeel or off flavour
Other tools
Keep going
Three more decision aids for the same problem set.