What is the difference between a 60 minute boil and a 90 minute one?

[dmtaylor]

I really don't believe undermodified malts exist. Or if they do, only in small amounts at boutiques as mentioned previously. Nowhere the average homebrewer will find any.

 

[Silver_Is_Money]

Some say that a base malt with an SNR (Kolbach Index) of ~35-37 will yield a beer with more mouthfeel than will the same malt if modified to an SNR of 43-45. And it is said that beer will be perceived to be excessively thin tasting if the index exceeds 45. Has anyone noticed if there is any truth to this for base malts at between 35 and 45?

 

[Broothru]

Oh Dave, DMS is not a thing of the past. But you are correct that it is less of a problem.

As pointed out above, DMS can rear its head when your grist has a high percentage of pils malt in it. That's because very lightly kilned malt like pils, has more SMM in it. SMM creates DMS. That SMM has to be converted to DMS by heating it in the kettle and then boiling the DMS out of the wort. The good thing is that its very easy to get DMS out of wort with about 30 minutes of a rolling, uncovered boil. Note that I said rolling and not volcanic. As long as you can see that the wort is turning over in your kettle fairly quickly (say an inch per second), its good enough. Its the exchange with the atmosphere that controls how fast DMS is expelled into the steam.

It takes about 30 minutes of covered simmering to get a decent percentage of the SMM converted into DMS. The wort doesn't really have to be boiling since its the wort temperature and not the vigor or movement that controls the SMM to DMS conversion. But here is where temperature does have an effect on how long you may need to perform your 'boil' process. If you're brewing at high elevation, the temperature of your wort will be lower than if you were at sea level. For that reason, high elevation brewers may have to 'boil' for a longer time in order to produce adequately DMS-free beers when brewing with a lot of pils malt.

For most brewers, you're probably at well under 2000 ft elevation and you probably don't need to resort to boils over 60 minutes. Be aware that time and heat damage wort and that damage accelerates the time in which a beer presents oxidation or aging effects. If you're brewing a beer style (like barleywine) that depends on the 'aging' effects of a long boil, then by all means, continue your long boils. But if you're brewing a regular style that you want to not show aging effects, then I strongly recommend that you not boil too long.

So, Martin...

To summarize the plethora of data in this thread (dare I say, "boil it down"...?), would you say that a post sparge/pre-boil 'rest' at >185F for :30 minutes to convert SMM, followed by a 'sufficient' boil (intensity and duration) is the key to reducing DMS? Post boil, rapidly cool the wort to <185F before any WP/hop stand to eliminate further SMM conversion?

If so I can see some significant benefit to a pre-boil pause @ 185F, then reducing the vigor and boil time of the wort to prevent Maillard reactions in my Continental lagers.

One related question: how much SMM is contained in either DME or LME, and can it (SMM to DMS conversion) be mitigated with an SMM 'rest' and rapid chill?

Many thanks to all. This is a great thread.

Brooo Brother

 

[Silver_Is_Money]

A local (within ~30 miles by road) Amish farmer grows and supplies "Sprouted Spelt Berries" to this regions various Amish bulk food stores, and on and off I've toyed with the idea of adding up to a pound of this local sprouted spelt to some of my beer recipes. Should I consider that a malted grain source such as this would likely be quite undermodified? I presume it is either merely air dried or perhaps (and at most) only minimally quasi-kilned. It may even have a bit of sprout chits still present.

 

[dmtaylor]

A local (within ~30 miles by road) Amish farmer grows and supplies "Sprouted Spelt Berries" to this regions various Amish bulk food stores, and on and off I've toyed with the idea of adding up to a pound of this local sprouted spelt to some of my beer recipes. Should I consider that a malted grain source such as this would likely be quite undermodified? I presume it is either merely air dried or perhaps (and at most) only minimally quasi-kilned. It may even have a bit of sprout chits still present.

Now THIS is most likely undermodified, yes. Close to chit malt I'm sure. This could be an interesting experiment. Actually I have a little Mennonite store up the road with the same type of grain options and been thinking of doing something like this myself, one of these days.....

 

[Birrofilo]

Now THIS is most likely undermodified, yes. Close to chit malt I'm sure. This could be an interesting experiment. Actually I have a little Mennonite store up the road with the same type of grain options and been thinking of doing something like this myself, one of these days.....

I don't know what chit malt is but I don't see why should those "Sprouted Spelt Berries" be undermodified. The modification is stopped by the application of heat. Until heat is applied, the germ goes on germinating. The process with which the malt is "killed" doesn't make it less modified. The producers might have waited actually more-than-usual before applying heat. If they merely air-dried the malt, then maybe the lenght of the process made the modification even greater.

 

[Beer Viking]

Some say that a base malt with an SNR (Kolbach Index) of ~35-37 will yield a beer with more mouthfeel than will the same malt if modified to an SNR of 43-45. And it is said that beer will be perceived to be excessively thin tasting if the index exceeds 45. Has anyone noticed if there is any truth to this for base malts at between 35 and 45?

Really basic question here, but what is SNR?

 

[VikeMan]

Really basic question here, but what is SNR?

Soluble Nitrogen Ratio, i.e. the ratio of soluble nitrogen to total nitrogen. aka SN/TN. For practical purposes, it's the same thing as the Kolbach index.

ETA: Nitrogen and Proteins are basically used interchangeably in the ratios, because in malt, they amount to the same thing.

 

[Birrofilo]

Some say that a base malt with an SNR (Kolbach Index) of ~35-37 will yield a beer with more mouthfeel than will the same malt if modified to an SNR of 43-45.

Is this meant with the same mash schedule?
I begin getting quite confused about why should one perform a protein rest if he managed to find a malt with a Kolbach index of 34 or 33.

The answer would be: to transform long-chain proteins into short-chain proteins (which give chill haze problems and maybe long-term taste problems). But wouldn't long-chain proteins actually give mouthfeel and head retention, while short-chain proteins don't?

 

[VikeMan]

But wouldn't long-chain proteins actually give mouthfeel and head retention, while short-chain proteins don't?

Mouthfeel comes from "medium length" proteins. So you want some breakdown, but not too much.

 

[Broothru]

Soluble Nitrogen Ratio, i.e. the ratio of soluble nitrogen to total nitrogen. aka SN/TN. For practical purposes, it's the same thing as the Kolbach index.

ETA: Nitrogen and Proteins are basically used interchangeably in the ratios, because in malt, they amount to the same thing.

Oh, MAN... I was flashing back to the old reel-to-reel tape deck days of the 70s when you had to have a separate Dolby noise reduction unit. As in: Signal-to-Noise Ratio. As Archie Bunker used to say, "Those were the days."

 

[Birrofilo]

Oh, MAN... I was flashing back to the old reel-to-reel tape deck days of the 70s when you had to have a separate Dolby noise reduction unit. As in: Signal-to-Noise Ratio. As Archie Bunker used to say, "Those were the days."

A dbx noise reduction unit coupled with a "metal" tape was the way to go

 

[Broothru]

A dbx noise reduction unit coupled with a "metal" tape was the way to go

Yeah, man. I had a four track Teac deck 8" reel-to-reel and a four channel Dolby NRU. Four corners of the room were covered with 4 Klipsch folded horn speakers and 80 watts per channel (x4) pumped through a Pioneer amp. When the Doobie Brothers rocked out "Listen to the Music", the whole neighborhood DID!

 

[Turricaine]

60 minutes is the theoretical time that it takes to get the bitterness out the hops.

I would have said ime the reason for a 90 min boil it to make sure that you lose at least 1 gallon in steam.

 

[VikeMan]

I would have said ime the reason for a 90 min boil it to make sure that you lose at least 1 gallon in steam.

Assuming no diacetyl concerns, why would you particularly want to lose at least one gallon of steam?