[jimrod]

How will it effect the fermability of the wort if I start the mash at 75* and gradually ramp up the temperature to 150* using a HERMS system?

Does this method utilize any "rest" points?

Will there be any difference doing this or preheating the water to 168* and "mash in" to end up at 150*?

[dmtaylor]

You will hit all the hotspot enzyme temperatures doing that.  I've done it.  I believe you will get a different beer than just mashing in the 150s right away.  The beer will generally tend to be thinner / more watery, more fermentable, and possibly more crystal clear with a slow rise mash like that as compared to a single infusion in the 150s.  Please feel free to run this as an experiment where you do two batches with the same grist to see what the differences are for yourself, and share results with us all if you do, that would be awesome.

[jimrod]

Actually that doesn't sound bad.

[kramerog]

You will hit all the hotspot enzyme temperatures doing that.  I've done it.  I believe you will get a different beer than just mashing in the 150s right away.  The beer will generally tend to be thinner / more watery, more fermentable, and possibly more crystal clear with a slow rise mash like that as compared to a single infusion in the 150s.  Please feel free to run this as an experiment where you do two batches with the same grist to see what the differences are for yourself, and share results with us all if you do, that would be awesome.

+1.  There are various rests below 150* including phytase, glucan rest, protein rests, and a beta-amylase rest.  These rests are generally not beneficial or necessary for modern malts.

[jimrod]

Does each hotspot add a different certain desirable characteristic to the beer? and what are they?

[denny]

How will it effect the fermability of the wort if I start the mash at 75* and gradually ramp up the temperature to 150* using a HERMS system?

Does this method utilize any "rest" points?

Will there be any difference doing this or preheating the water to 168* and "mash in" to end up at 150*?

Unless you use a malt that really needs a step mash, you will possibly end up with a very thin, over attenuated beer.

[jimrod]

I just plucked this from the Beer Blog by BeerSmith.
http://beersmith.com/blog/2009/07/16/mashing-for-all-grain-beer-brewing/

Here’s a summary of the major enzyme groups found naturally in malted barley and their active range:

    Phytase (86-126 F) – Lowers the pH of the mash. Lowering the mash pH has a number of benefits,        though a Phytase rest is rarely used by modern brewers.
    Debranching (95-112 F) – Helps to increase the solubility of starches resulting in increased extraction for certain malts.
    Beta Glucanese (95-113F) – Breaks down the gummy heavy starches, which can help improve stability and extraction, particularly for mashes high in proteins and adjuncts such as wheat.
    Pepidase (113-131F) – Produces free amino nitrogen, which can aid in fermentation.
    Beta Amylase (131-150F) – Produces maltose, the main sugar fermented in beer.
    Alpha Amylase (154-162F) – Produces a variety of sugars, including maltose and also some unfermentable sugars. Mashing at the higher end of this range produces more unfermentables and therefore more body in the finished beer.

But it doesn't sound like any of these rests are bad?

[denny]

I just plucked this from the Beer Blog by BeerSmith.
http://beersmith.com/blog/2009/07/16/mashing-for-all-grain-beer-brewing/

Here’s a summary of the major enzyme groups found naturally in malted barley and their active range:

    Phytase (86-126 F) – Lowers the pH of the mash. Lowering the mash pH has a number of benefits,        though a Phytase rest is rarely used by modern brewers.
    Debranching (95-112 F) – Helps to increase the solubility of starches resulting in increased extraction for certain malts.
    Beta Glucanese (95-113F) – Breaks down the gummy heavy starches, which can help improve stability and extraction, particularly for mashes high in proteins and adjuncts such as wheat.
    Pepidase (113-131F) – Produces free amino nitrogen, which can aid in fermentation.
    Beta Amylase (131-150F) – Produces maltose, the main sugar fermented in beer.
    Alpha Amylase (154-162F) – Produces a variety of sugars, including maltose and also some unfermentable sugars. Mashing at the higher end of this range produces more unfermentables and therefore more body in the finished beer.

But it doesn't sound like any of these rests are bad?

Many of them can be bad and most if them are at least unnecessary.  Almost all modern malts are malted to be used in a single infusion mash.  Commercial breweries couldn't afford to operate otherwise.  You should always base rest temps on what the malt needs, not what the recipe says or what you feel like doing.

[morticaixavier]

I just plucked this from the Beer Blog by BeerSmith.
http://beersmith.com/blog/2009/07/16/mashing-for-all-grain-beer-brewing/

Here’s a summary of the major enzyme groups found naturally in malted barley and their active range:

    Phytase (86-126 F) – Lowers the pH of the mash. Lowering the mash pH has a number of benefits,        though a Phytase rest is rarely used by modern brewers.
    Debranching (95-112 F) – Helps to increase the solubility of starches resulting in increased extraction for certain malts.
    Beta Glucanese (95-113F) – Breaks down the gummy heavy starches, which can help improve stability and extraction, particularly for mashes high in proteins and adjuncts such as wheat.
    Pepidase (113-131F) – Produces free amino nitrogen, which can aid in fermentation.
    Beta Amylase (131-150F) – Produces maltose, the main sugar fermented in beer.
    Alpha Amylase (154-162F) – Produces a variety of sugars, including maltose and also some unfermentable sugars. Mashing at the higher end of this range produces more unfermentables and therefore more body in the finished beer.

But it doesn't sound like any of these rests are bad?

Many of them can be bad and most if them are at least unnecessary.  Almost all modern malts are malted to be used in a single infusion mash.  Commercial breweries couldn't afford to operate otherwise.  You should always base rest temps on what the malt needs, not what the recipe says or what you feel like doing.

also, these are only the effects on starches. There are also protease reactions that degrade proteins needed for foam formation and retention as well as body and mouthfeel. Give it a try for sure! use a belgian recipe like a tripple or similar as those are the historical recipes I see most often using complex mash schedules (although even they don't do that anymore most of the time)

[majorvices]

As Denny has stated, most brewer's malts these days are malted with the intend that the brewer is going to do a single infusion mash. It's a lot cheaper for breweries to hit one or two temps rather than have to ramp up through several. That said, you might could give it a go on a beer such a a saison or a tripel that you intend to be exceptionally dry - because one thing I expect is that you will have a very dry beer depending on how fast you ramp through the phases. Also, how slow or fast you ramp through the phases could have a lot of consequences on your beer including poor head retention and low mouth feel. If you could ramp through quickly enough you would probably be fine.

[HoosierBrew]

As Denny has stated, most brewer's malts these days are malted with the intend that the brewer is going to do a single infusion mash. It's a lot cheaper for breweries to hit one or two temps rather than have to ramp up through several. That said, you might could give it a go on a beer such a a saison or a tripel that you intend to be exceptionally dry - because one thing I expect is that you will have a very dry beer depending on how fast you ramp through the phases. Also, how slow or fast you ramp through the phases could have a lot of consequences on your beer including poor head retention and low mouth feel. If you could ramp through quickly enough you would probably be fine.

Keith, do you step mash those beers, out of curiosity ?  I mash tripel and saison ~ 147F (occasionally 146F) and get a nice dry beer. Just wondering.

[majorvices]

As Denny has stated, most brewer's malts these days are malted with the intend that the brewer is going to do a single infusion mash. It's a lot cheaper for breweries to hit one or two temps rather than have to ramp up through several. That said, you might could give it a go on a beer such a a saison or a tripel that you intend to be exceptionally dry - because one thing I expect is that you will have a very dry beer depending on how fast you ramp through the phases. Also, how slow or fast you ramp through the phases could have a lot of consequences on your beer including poor head retention and low mouth feel. If you could ramp through quickly enough you would probably be fine.

Keith, do you step mash those beers, out of curiosity ?  I mash tripel and saison ~ 147F (occasionally 146F) and get a nice dry beer. Just wondering.

Nope. Don't really find any need to step mash for dry beers.

[majorvices]

I guess I'm just saying I expect he will get a dry beer, so might as well do it on one of those styles.

[HoosierBrew]

I guess I'm just saying I expect he will get a dry beer, so might as well do it on one of those styles.

Cool.  I used to step mash some back when some of the malts weren't as modified, but I can hardly find a reason to now. I pretty much single mash everything, lagers included.

[majorvices]

It's probably been at least 10 years ago but I remember an article in BYO or Zym about a traditional saison brewery who started off at something like 37C (99F) and ramped all the way to 76C (170F) - or something along those lines, to get a really dry beer. I don't remember much about it but there was some people talking about how to do it with a RIMS/HERMS type set up. Some clever searching could maybe dig that up.