 Tea Spit
On Oct 16, 5:18 pm, Square Peg <Square...@Round.Hole> wrote:
> On Thu, 16 Oct 2008 05:39:59 -0700 (PDT), Space Cowboy
>
> <netst...@ix.netcom.com> wrote:
> >Alkaline or acidic? The foam that appears on some teas.
>
> pH paper?
Tea is generally about pH 6 to 6.5 i.e mildly acid side of neutral. I
don't believe acidity has any affect on foam or vice versa. I
generally suspect washing up detergent when I see foam on catering
tea. However, tea seed contains high level of saponin (a natural
surfactant - 10 to 15% by weight and an important industrial source).
Tea leaf has trace levels of saponin (not much - it's toxic), which
may on occasion be sufficient to cause a surface froth. I am not
aware what field conditions encourage saponin in tea leaf - a nice
study for someone.
Nigel at Teacraft | 
