[hospter81]

I was reading brewing lager beer book. Noonan says about infusion mashing: "Beers that will be served very cold may show a protein haze if malf or more than 1.6 percent nitrogen (10 percent protein) wit a soluble nitrogen ratio less than 40 percent is mashed without a protein rest".

Im using rarh base malt with 12.13 total malt protein and a soluble nitrogen ratio of 46...do i have to perform a protein rest?

[denny]

I was reading brewing lager beer book. Noonan says about infusion mashing: "Beers that will be served very cold may show a protein haze if malf or more than 1.6 percent nitrogen (10 percent protein) wit a soluble nitrogen ratio less than 40 percent is mashed without a protein rest".

Im using rarh base malt with 12.13 total malt protein and a soluble nitrogen ratio of 46...do i have to perform a protein rest?

Absolutely not.  It could even be detrimental to the beer.  In general, a protein rest is seldom necessary.  Noonan wrote that book a long timer ago, and it was aimed at commercial brewers.  Ingredients and techniques have changed a lot since then.

[davidgzach]

A short protein rest can help with efficiency and head retention but as Denny said it is absolutely not necessary and could be detrimental.  Modern malts are much better modified than when that book was written.

Dave

[a10t2]

I think the advice is actually pretty good, but Denny's right that a protein rest would seldom be necessary. It would be highly unusual to find a malt with those specifications (TP >10%, SNR <40%). Unless I'm misinterpreting, your Rahr doesn't even qualify (TP 12.13%, SNR 46%).