Protein Rest-Can This Be Correct?

[trentm]

I have always done a protein rest at 130F for 30 minutes because that's how I learned and am resistant to change. I always use Belgian Pilsner for a base malt and sometimes have a bit of a chill haze issue even though I boil hard for 90 minutes, chill fast to 60F (15 to 20 minutes after a 15 minute rest to drop the hops and hot break) and then remove the cold break after a 2 hour rest.

I have often read that a protein rest is no longer necessary when using highly modified malts and that SNR is a good indicator of modification. The malt I use has a SNR of ~41. But may range from 35 to 45 according to Dingmans specs.

Now here is the kicker: I just read an article by Greg Noonan where I clipped the following statement (link to full article:http://morebeer.com/brewingtechniques/bmg/noonan.html)

"Brewers can accommodate increases in total protein and SNR by adding or modifying low-temperature rests. Decreases are accomodated by shortening the duration of or deleting low-temperature rests."

Question: Am I interpreting the above statement to mean; the higher the SNR the greater the need for a protein rest?

Note: I recently read a post in the yeast forum where someone quoted Noonan from his book "Brewing Lager Beer" stating the opposite. So is this a misunderstanding or misprint?

 

[MrHadack]

Skip the protein rest, except under special circumstances.

A protein rest activates two enzymes. One breaks large proteins down into medium proteins, and the other works on the medium and small proteins (breaking medium to small, and small proteins into their components.) The medium proteins are what give you head retention and body in the beer. With today's highly modified malts, the long chains have already been broken down for the most part. So when you do a protein rest with highly modified malt, you are breaking down medium chains to small, but there aren't very many large chains being broken down to medium chains! This means you are potentially robbing your beer of body and head retention.

If you are using a lot of flaked grains (which have not been malted at all) you will have these long chains present and can potentially benefit from a protein rest. But even then we're probably talking about a grain bill that is comprised of 1/3 or more of these unmodified grains.

 

[mabrungard]

Agreed with above, you rarely need a protein rest with modern malts. The level of modification is high enough to NOT warrant it. You might want a low temp rest when mashing grists with a lot of wheat or rye, but otherwise it is probably counterproductive.

If you are worried about fermentability, a slightly lower temperature rest in the mid to upper 140F range can take care of that. I've heard many commercial breweries including that approach along with a rest in the low 150F range.

 

[brewfun]

IQuestion: Am I interpreting the above statement to mean; the higher the SNR the greater the need for a protein rest?

Note: I recently read a post in the yeast forum where someone quoted Noonan from his book "Brewing Lager Beer" stating the opposite. So is this a misunderstanding or misprint?

Quite the opposite. The higher the SNR % the less need for a protein rest.

SNR is created in the malting process and is one of several indirect measurements of malt modification. Since SNR is expressed as a % of the total nitrogen in the malt, the higher the number, the more modification can be assumed.

So, the confusion might be related to whether Noonan was talking about SNR or the total nitrogen content. A brewer wants the former to be higher, and the latter lower.