Protein Rest - What Is It And Is It Handy?

[manticle]

I don't do them and my beer is fine. Big Whoop to protein rests - waste of time.

Great for those who want to be head brewer. Not necessary for those who don't have their head in their arse.

I've made great beer without them too Nick. I don't think anyone suggested you need to - I was just relating my experience with them contradicting the idea that they will necessarily suffer if you do them.

Head in arse or just trying different techniques in order to see what happens?

Not necessary? Of course not. What's necessary got to do with anything?

 

[MHB]

Now that's just not true, there's lots of different ways to be an ********.

Sorry TB I think our good mate is using all of them.

MHB

 

[hsb]

I made my Weisse (with Protein Rest) and tried out raising the Mash temp a little (5C) using my Immersion Heater as per earlier in thread. For me... a bit of a disaster! It scorched very badly quite quickly. Left a strong scorched grain smell in Mash and stuck firm to Immersion Heater which I foolishly plunged straight back into HLT ruining the water in there as well (went murky and smelt like stale bongwater instantly). Could well just be my own particular Immersion Heater, I tried to keep it on the move constantly but it scorched within 3-4 minutes. YMMV I don't mind having given it a try.

Oh well, worth a try cheers, back to trying for Mash temperatures from fiddly additions of hot/cold water, always my weakest suit on brewdays. (/me wishes for surprise RIMS/HERMS Xmas present)

Hopefully it hasn't damaged my Weisse too much, it still had a bit of a scorched aroma at the beginning of the boil but seemed to disappear by the end.

Following on from my underattenuated, diacetyl-fest Pilsner I'm forcing down at the moment, I am hoping for Xmas glories on brewdays to rekindle my enthusiasm/confidence.

 

[manticle]

I made my Weisse (with Protein Rest) and tried out raising the Mash temp a little (5C) using my Immersion Heater as per earlier in thread. For me... a bit of a disaster! It scorched very badly quite quickly. Left a strong scorched grain smell in Mash and stuck firm to Immersion Heater which I foolishly plunged straight back into HLT ruining the water in there as well (went murky and smelt like stale bongwater instantly). Could well just be my own particular Immersion Heater, I tried to keep it on the move constantly but it scorched within 3-4 minutes. YMMV I don't mind having given it a try.

Interesting. I get nothing like that with mine. I also plunge mine into the HLT and just get water with a couple of bits of grain in it. Curious to know what causes such different experience.

For a weizen maybe next time try a decoction or two whill will add some lovely melanoidens in there.

 

[hsb]

Mine is an older one off eBay, a Grimwood. The coils are very tight, that may be the trouble, no space for the grains to escape, the whole thing seemed to clag up quite quickly.
I'm sure the HLT stuff up was due to it being totally coated like a big stick of burnt porridge. It was worth a try. I might try uncoiling it a little to allow space.
I do hate hitting temps in the Mash, in so much as I can hate anything to do with making beer!

Decoction could be good, maybe next time. This was my first wheat beer and only my third All Grain 'lager' of any kind, I've yet to really nail a Lager so fingers crossed it comes out well.

 

[Droopy Brew]

Bringing up an old thread here- and one that I have read a number of times when working out my mash sched for Weizens.

I had an interesting conversation today in my HBS with a guy that is very well regarded and gave me some good feedback.

The beer tasted was Les the weizguys awesome Schnieder wiezen- have brewed it a number of times and it is a must do. Anyway the mash sched was 15 @ 53C, 60@ 63C deconcoct to 72C for 15min. The beer has a great balance of clove and banana and the body is pretty good.

This guy gave it some good wraps, saying that it was one of the best weizens he has had in a long time but picking it appart he thought the body and head retention could have been stronger and the decoction qualities were hidden. After telling him my mash sched he related a story from one of the countries best brewers years ago (who's name I have forgotten). Anyway the guts was he looked at this guys weizen and said have you done a protien mash? He had and the guru had picked up on the size and tightness of the bubbles (not tight enough or small enough he reckoned). he said never do a Protien mash on a wheat beer- you want the long chain protiens in there for that extra body that makes a wiezen a weizen.

He also suggests letting it cool slowly to promote less cold break, again to retain some protiens in the wort.

So this flys against a lot of what is said here and it does make some sense to me and I know this guy is well regarded. I am also aware of the whole opinion/arsehole ratio.

I thought it might be a point worth discussing 5 years on from this original thread and see if thinking has changed or if others agree with this.

 

[antiphile]

It's my understanding that the so-called "protein rest" is a bit of a misnomer. Yet in my small mind it does perform some useful functions, and I have to admit I do it more often than not in mashes. (See, for example, a short article called The Science of Step Mashing.)

Though apart from the advantage of breaking down some longer chained proteins (which is very advantageous), I like to do a step at that temp when I dough in (unless I want to do an acid rest) in order to minimise the risk of dough balls, since this is below gelatinisation temp for most grains.

But for dummies like me, it's a lot of learn from experience; and, if you're on a good thing, stick to it!

 

[mfeighan]

Yeah i agree with antiphile, i usually mash in at target temp of 55 (after a suggestion from nev), stir get the chunks etc out and allow my grain bed to set before adding heat with my rims. Usually takes about 5-10 mins to settle and run clear which is when i add heat for the sacc step(s). After looking at the link i guess i am doing the right thing as i havent had a hazy beer in a very long time.

 

[Droopy Brew]

Thats true, but to a certain extent hazy is what you are chasing with a Weizen which was the thinking behind avoiding a P rest with this particular style.

 

[TheWiggman]

As an aside, for almost every brew I strike at 59-60°C for a combined protein-glucose rest at 55°C. I use HERMS, so the HERMS water is already sitting at a temp higher than the rest temp. I mash in, rest for 5 mins, then slowly bring back the flow to prevent getting a stuck mash. By the time I've reached full flow 8-10 mins is up and I can step up to my sacc rest temp.
I've often read - on AHB - that combined with a 72°C for 15-20 mins, a protein rest aids in head retention. I can't confirm this with honest results, but I did so with a lager (96% pils, 4% crystal, sugaz) and last night the beer maintained a thin head from top to bottom.

 

[Nizmoose]

I made my Weisse (with Protein Rest) and tried out raising the Mash temp a little (5C) using my Immersion Heater as per earlier in thread. For me... a bit of a disaster! It scorched very badly quite quickly. Left a strong scorched grain smell in Mash and stuck firm to Immersion Heater which I foolishly plunged straight back into HLT ruining the water in there as well (went murky and smelt like stale bongwater instantly). Could well just be my own particular Immersion Heater, I tried to keep it on the move constantly but it scorched within 3-4 minutes. YMMV I don't mind having given it a try.

Oh well, worth a try cheers, back to trying for Mash temperatures from fiddly additions of hot/cold water, always my weakest suit on brewdays. (/me wishes for surprise RIMS/HERMS Xmas present)

Hopefully it hasn't damaged my Weisse too much, it still had a bit of a scorched aroma at the beginning of the boil but seemed to disappear by the end.

Following on from my underattenuated, diacetyl-fest Pilsner I'm forcing down at the moment, I am hoping for Xmas glories on brewdays to rekindle my enthusiasm/confidence.

I've had the same experience as manticle, I love my immersion heater, use it for 3-4 steps and always make sure I'm stirring the mash really well for as long as the heater is on and then once my step is hit I unplug it keep stirring for a few seconds then take it out and put it into a bucket of water to stop it burning up. The only thing I can think of that might be scorching your mash is that I BIAB so my water to grain ratio is quite large (6ishL per kg), not sure what method manticle uses but if you were doing a traditional 2-3L per kg then I can perhaps envisage a problem occurring with scorching?

 

[dannymars]

getting back to the topic at hand.... I cannot find the answer to the obvious question... What does a protein rest do to the finished beer? more hazy? less hazy? does it matter how long you do it?

I do them, but only because I like doughing in lower as it's easier to stir and not so hot as you can burn yourself it it splashes around etc. I still get chill haze in my beer, but I don't really care about that tbh.

 

[Nizmoose]

The point as far as I'm aware is to improve head retention, not sure about haze. And also people seem to use it as a way to hydrate the mash before reaching sacch temps. Also seems that a short (5-10 Min) rest is recommended before you start getting negative effects. So in short: good for hydration, head retention, don't do it for too long.

EDIT: I should mention I'm not sure if I'm using the term hydration correctly but if I'm not mistaken I believe the purpose is to disperse enzymes throughout the mash before reaching sacc. temps??? Manticle?

 

[klangers]

Let's get some science involved.

A "protein rest" is simply holding the mash at the temperature at which beta glucan is most efficiently/rapidly broken down (into sugars). Really we should be calling it a beta glucan rest, as it's not as if ALL proteins are being broken down at this temperature. Alpha and beta amylases have their own particular ways of breaking down starch, and neither enzyme breaks down ALL starch.

Just like anything, it's not as simple as saying "never ever do a protein rest" or "always do a protein rest". It simply depends on your ingredients and your target beer.

Now, beta glucan is a family of proteins which occur in plant materials. Oats, for example, is very high in beta glucans. Barley and wheat have thousands of proteins in them aside from beta glucan. One very prominent protein which is currently very popular to talk about and pretend not eating it is healthy is gluten. Gluten won't be broken down with beta glucan in a protein rest and therefore will still give you the typical protein effect: stronger head, bigger mouthfeel and more numerous and powerful farts.

If you don't do a protein rest whilst mashing oats, you may have a bad time with stuck sparges and all sorts because the beta glucan has not been broken down (and by now at saccrification temperatures the enzyme which does that is denatured). On the other hand, if you have an excessively long protein rest you may find that the smoothness that oats adds is removed.

Beta glucan tends to be more concentrated in under-modified malts. However, well modified malts may have beta glucan levels that are higher than the brewer would like. Now, there are many reasons why malts are deliberately under-modified (namely various attempts at reducing malting losses or preserving high enzyme levels). Traditionally, pilsner malts were under modified. Now that everyone is chasing the dollar$ these days all base malts are well modified, and pilsner malts are essentially just lighter-kilned versions of pale ale malts.

Moral of the story: protein rests typically break down beta glucan. If you don't expect high beta glucan levels in your grist (ie no oats, rye, under-modified malts or various adjuncts), there probably isn't a need to reduce the beta glucan levels.

Also: haze is cause by multitudes of proteins; not just beta glucan.

 

[krausenhaus]

Just to clarify, beta-glucans are polysaccharides, not proteins. At protein rest temperatures, you have proteolytic enzymes working on protein and beta-glucanases working on beta-glucans. Targeting long proteins is for improving haze & head retention, while for beta glucans it's gummy mashes.

 

[Adr_0]

My understanding is that with modern malts the rest in the 45-55°C is completely unnecessary and detrimental. The purpose of this rest is to promote activity of enzymes that will break down protein into the lowest molecular weight region, i.e. make them soluble in the beer rather than floaty. These shorter/lower molecular weight proteins are broken down from larger proteins, a lot of which are the 'head forming/retaining' proteins - hence why a rest at this temp would be detrimental for modern malts.

As many have said, economy/business drives refinement of a product and most (every?) maltsters recognise that if they can carry out this breakdown when malting the barley, it saves the brewer doing it. It has always puzzled me why Weyermann recommend a mash temp of 52°C for their malts but they seem to be pretty well modified.

This range (45-55°C), as the science stands, would be required for oats, flaked barley and I guess rye. How much can you add to the grist before you need to do a rest? Who knows... I guess you can do a slow pass through this range if you only have a few percent.

The actual proportion of protein in the malt/adjunct is probably the primary thing to consider if you're going to do a protein rest. 9-10% would be normal - NOT requiring a rest at all - while 11-13% is high. Aussie/British/American malt falls into the first bracket while oats are probably 13%.

Greg Noonan references the Kolbach ratio in making the decision on protein rest temperature: if the Kolbach ratio (ratio of soluble to insoluble nitrogen) is below 37%, a protein rest of 50°C is suitable; and if the ratio is 37-40% then this rest should be done at 55°C or potentially slightly higher. This is recognised as being within the beta amylase region, so modify your sacch schedule if you are looking at spending more than 15min here.

German Munich and wheat malt potentially push the 11.5-13% range and pils is closer to the normal range, being 9-11.5%, so a protein rest "should" be done for these. The Kolbach index on all of these malts is potentially pretty high, so really the 55°+ range is where you want to be not 50-52°C. Funny, it's almost like Manticle knows what he's talking about when he says 5-10min at 55°C does the trick.

For oats, flaked barley, etc. you should probably spend 10min or so around 50-52°C.

I'm doing two dunkels this weekend and will aim for 56°C for 15min and decoctions, as there's a 60ish% Munich II in there: highish protein (up to 12.5) but lots of soluble nitrogen (Kolbach 38-47%).

Would your beer be delicious without doing these rests? Yes, of course...

 

[///]

Most of the time it is focused on processing, better viscosity in the mash tun and to also save filters, particularly if you use sterile cartridges or lenticular pad filters

Malt with high better glucans causes me all sorts of grief on the mash filter at work. Aussie ale malts are less modified than Pils and slows down the transfer thru the mash filter and effects extract. You can see the BG and protein on the sheets when we dump
Out the grain

 

[RelaxedBrewer]

I know this is an old thread but I just came across it today.

The post by klangers got a lot of likes and it seemed as though people were accepting it as fact. Nothing personal, however I am pretty sure it is not factually correct.

Let's get some science involved.

A "protein rest" is simply holding the mash at the temperature at which beta glucan is most efficiently/rapidly broken down (into sugars). Really we should be calling it a beta glucan rest, as it's not as if ALL proteins are being broken down at this temperature.

A protein rest is not the same as a beta-glucan rest. We are not simply trying to break down beta-glucan with a protein rest.
Beta-glucans are broken down by beta-glutanases and as brewers we care most about 1,4 beta-gulcanase which has an optimal operating temperature of ~45C. So if you are worried about making porridge in your mash with a high amount of unmalted grains you should mash rest at ~45C.

A protein rest achieves a different outcome. During a protein rest two different enzymes (Proteinase and Peptidease) are operational that effect proteins. Peptidease as an optimal temperature of ~50C and converts medium and short chain proteins into their components. Proteinase has an optimal temperature of ~58C and breaks long chain proteins down into medium chain proteins (medium chain proteins are positive for mouthfeel and head retention while long chain proteins can cause haze and stability issues).

Some beta-glucanase activity will occur during a protein rest as beta-glucanase is active up to ~60C, but it will be less optimal then at a lower temp (~45C) and not the primary reason why you should be doing a protein rest.

I know I am late to the party, but I thought I should clear this up for anyone else that comes along after trying to find out about protein rest.

 

[klangers]

All good mate, I appreciate the clarification. I got confused with the chemical names. being a mechanical engineer, this brewing chemistry thing is quite new to me, but getting there!.

 

[MHB]

Its a lot more complicated than a Do/Don't. Considering how well modified modern malt is (Modified in terms of break down cell walls, glucans and proteins) good maltsters now have such control of the processes that they can turn out pretty much whatever you want. What the big brewers want is simple to use malt that has a high yield and that's exactly what they get. The other specification is the right range of protein degradation products for both body and head.

For Ale brewing with little or no adjunct I think its pretty pointless. Ale with a bunch of adjunct (say Pacific Ale) then both Glucan and Protein rests are beneficial.
For Lager, well a loud maybe, not really necessary, tho a decoction still has some advantages but I wouldn't bother for anything other than a very special beer of using a floor malted grain, chit malt...

The two best head building proteins are Protein-Z and LTP1, the much talked about Z is according to the latest research nearly all produced as a byproduct of B-Amylase production during germination, not by a rest at 72oC , Lipidase Transfer Protein 1 (LPT1) is also made during germination. Too long a proteinase rest can degrade these and other medium molecular weight proteins and actually reduce the heading potential of beer (yes its a measurable parameter) significantly. The high MW protein is coagulated during the boil, so little point to trying to degrade that.

There are actually four types of Protease active at/around the temperature most people call a protein rest, don't worry there are over 20 inside a yeast cell, some of which are real head destroyers (Protease-A being the worst) and one of the main reasons we rack/dump old yeast.

I think I would give it a miss, without a dam good reason not to.
Mark