Having collected a sizeable amount of data (72 samples
corresponding to variations of 5 paste recipe parameters and
evaluated across 12 different criteria…72 times 5 times 12 …
Pheew!), I used statistical data analysis tools to identify
relevant correlations and trends.
To make a very long story short, three parameters appeared to
strongly impact the quality of the resulting paste: The cooking
temperature, starch to water ratio and sieving process.
Conversely other parameters, such as the source of starch,
pre-soaking or the cooking method used, did not show any
significant impact on paste properties.
In terms of cooking temperature there was a clear trend for
batches cooked under 80°C (of the mixture, not the setting) to have
lower tack, cohesiveness and applicability than the others.
These 'low temperature' mixtures had a matte appearance and did
not reach the 'shiny' and 'transparent' stages during cooking (see
my previous post).
Pastes using lower starch:water ratios such as 1:3 were more
challenging to cook and the resulting products had applicability
and ease of dilution issues. Pastes using higher starch:water
ratios such as 1:10 showed significantly less tack.
Finally sieving (which here meant at least 3 cycles of sieving
of the paste after cooking) led to very smooth and 'creamy'
textures, and significantly improved the applicability of the
samples. In fact, sieving even might improve a 'borderline' product
to a 'conservation grade' paste.