Optimum pre-infusion pressure

[tailspn]

I'm rigging a single head Linea for pre infusion using regulated water mains pressure. My unregulated mains pressure is 44psi. I've read estimates for the ideal pre infusion pressure anywhere between 25 and 40psi. Any comments and suggestions for optimum pressure would be greatly appreciated.

Thanks
Tom

PS, I posted this question also on alt.coffee. I'll summarize/copy anything conclusive there to here as I receive them.

[barry]

i would imagine "ideal" would partly depend upon the coffee and brew water temp.

i suggest you try multiple shots at various settings and find out which you believe gives the best results.