Can one just do an infusion mash at say 160-165*F to get a starchy mash instead of doing a turbid mash? I know the turbid mash is authentic way of making sours/lambics but will a high temp infusion mash yield a high starch unconverted wort suitable for sours? Or is a TM the only way?
Not sure about that, but I followed themadfermentationist's turbid mash schedule and worked well for me, not rally that much harder or more time. Check out his webpage/blog, tons and tons of great inof.
turbid mashing has a lot to do with gelatinization of an unmalted wheat component. i have had good luck doing a cereal mash on the unmalted wheat instead. check out my procedure at http://www.overcarbed.com/?p=2015
Ithaca made Brute with a low 160s F Sacch rest with good results. There were some other odd things about that recipe/procedure too. Most sours brewed in America don’t get the full turbid treatment, so you can make a great beer, but it may not be exactly the same as the result from a turbid mash.
I believe Russian River mashes at 160ish. I have been doing it for all my sours (outside of turbid mashing) . It knocks out most of the beta amylase but not the alpha. So you get good efficiency and a pretty unfermentable wort. I believe I got around 55% attenuation mashing at 162F and using a wy1335 as the primary strain.