Some ideas on HK style milk tea making

Instead of stocking bag:

Using a wide basket, so that tea leaves is spread on  the base., similar to bunn coffee basket

Using a pump to re circulate tea if necessary , similar to aquarium pump

Besides a timer, Use light sensor to determine the color change of tea, eg brix meter or refractometer?

The objective is to maintain extraction consistency 

Infusion with stirrer vs re circulation, which is better?

Assam tea 烏沃 uva

100 deg C

Leave the tea leaves to steep and infuse into the water, between 4 and 5 minutes, but no longer otherwise the tannins will yield a bitter and harsh taste.

Milk Denature temperature is 70 degrees, so best to mix milk below 70 deg c

高山茶， eg 烏龍

90-100 deg c

Reference

Mpweekly