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General Category => General Homebrew Discussion => Topic started by: JKL on May 16, 2011, 05:01:27 PM

Title: Benefits of a 90 minute boil?
Post by: JKL on May 16, 2011, 05:01:27 PM
I've noticed that a lot of veteran brewers employ a 90 minute boil.  Aside from driving off DMS and increasing wort carmelization are there any other benefits?
-J.K.L.
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 16, 2011, 05:07:47 PM
Longer boils tend to darken the wort and there are maillard reactions taking place producing more melanoidins that enhance the maltiness of the wort. Not to mention increased hop isomerization or enhanced hop bitterness. The longer boil also concentrates these flavors that are created during the boil. Driving off DMS is probably one of the biggest reasons to boil longer but these other attributes also come into play as well.
Title: Re: Benefits of a 90 minute boil?
Post by: Mark G on May 16, 2011, 05:19:59 PM
If I'm using pils malt, I'll go 90 minutes to drive off the DMS. I also use a 75 minute boil with non-pils grain bills as well, just so that I have 15 minutes to get the hot break before I add any hops, reducing the risk of boil-over.
Title: Re: Benefits of a 90 minute boil?
Post by: denny on May 16, 2011, 06:17:07 PM
Technically speaking, you can't get caramelization in the boil.  And melanoidins are colors, not flavors, so they won't enhance the maltiness of the wort.
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 16, 2011, 06:33:21 PM
Technically speaking, you can't get caramelization in the boil.  And melanoidins are colors, not flavors, so they won't enhance the maltiness of the wort.

Agreed they are are brown, high molecular weight heterogeneous polymers.

They are an integral part of the maillard reaction which enhances maltiness. When sugars and amino acids combine (through the Maillard reaction) at high temperatures there's nonenzymatic browning similar to caramelization. In the process, hundreds of different flavor compounds are created.
Title: Re: Benefits of a 90 minute boil?
Post by: denny on May 16, 2011, 06:45:12 PM
Technically speaking, you can't get caramelization in the boil.  And melanoidins are colors, not flavors, so they won't enhance the maltiness of the wort.

Agreed they are are brown, high molecular weight heterogeneous polymers.

They are an integral part of the maillard reaction which enhances maltiness. When sugars and amino acids combine (through the Maillard reaction) at high temperatures there's nonenzymatic browning similar to caramelization. In the process, hundreds of different flavor compounds are created.

Agreed on all counts...I was in pedantic mode!
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 16, 2011, 06:50:05 PM
Technically speaking, you can't get caramelization in the boil.  And melanoidins are colors, not flavors, so they won't enhance the maltiness of the wort.

Agreed they are are brown, high molecular weight heterogeneous polymers.

They are an integral part of the maillard reaction which enhances maltiness. When sugars and amino acids combine (through the Maillard reaction) at high temperatures there's nonenzymatic browning similar to caramelization. In the process, hundreds of different flavor compounds are created.

Agreed on all counts...I was in pedantic mode!

 ;D
Title: Re: Benefits of a 90 minute boil?
Post by: bonjour on May 16, 2011, 07:02:00 PM
OK,
so what happens to the sugars (solids) when the water they are being carried by suddenly disappears into a cloud of water vapor?

Traditionally caramelization occurs when water is removed and the resulting sugars heat up, as in making candy.
Title: Re: Benefits of a 90 minute boil?
Post by: tschmidlin on May 16, 2011, 07:11:19 PM
OK,
so what happens to the sugars (solids) when the water they are being carried by suddenly disappears into a cloud of water vapor?

Traditionally caramelization occurs when water is removed and the resulting sugars heat up, as in making candy.
Yes, you need to remove enough water for the temperature to get hot enough for the sugars to caramelize.  We never reach that point with wort.  For example, maltose doesn't caramelize until over 350F.  Glucose around 320F.  Wort - 212F.  Your wort might hit 215F though Fred. :)

<edit>I found this cool boiling point calculator.  Enter the brix, it tells you the bp.
http://www.sugartech.co.za/bpe/index.php
Title: Re: Benefits of a 90 minute boil?
Post by: gordonstrong on May 16, 2011, 07:16:40 PM
Agreed on all counts...I was in pedantic mode!

Is "pedantic hippy" an oxymoron?  Hmmm, need to ponder that over a beer.
Title: Re: Benefits of a 90 minute boil?
Post by: jeffy on May 16, 2011, 07:33:16 PM
Agreed on all counts...I was in pedantic mode!

Is "pedantic hippy" an oxymoron?  Hmmm, need to ponder that over a beer.
Once upon a midnight dreary
While he pondered weak and weary
Over many a pint of quaint and hoppy brew
While he nodded, nearly napping, suddenly there came a tapping
As if some gentle hippy came tipsy to correct his point of view
Tis some pedantic hippy
Only this and nothing new.
Title: Re: Benefits of a 90 minute boil?
Post by: JKL on May 16, 2011, 07:43:07 PM
Aside from driving off DMS and increasing wort carmelization are there any other benefits?
-J.K.L.
high molecular weight heterogeneous polymers.


Yeah, that's what I meant to say but I didn't want to confuse anyone. ;)

-J.K.L.
Title: Re: Benefits of a 90 minute boil?
Post by: denny on May 16, 2011, 08:47:42 PM
Agreed on all counts...I was in pedantic mode!

Is "pedantic hippy" an oxymoron?  Hmmm, need to ponder that over a beer.

Good idea...I'll join ya!
Title: Re: Benefits of a 90 minute boil?
Post by: denny on May 16, 2011, 08:48:21 PM
Agreed on all counts...I was in pedantic mode!

Is "pedantic hippy" an oxymoron?  Hmmm, need to ponder that over a beer.
Once upon a midnight dreary
While he pondered weak and weary
Over many a pint of quaint and hoppy brew
While he nodded, nearly napping, suddenly there came a tapping
As if some gentle hippy came tipsy to correct his point of view
Tis some pedantic hippy
Only this and nothing new.

You RAWK!!  ;)
Title: Re: Benefits of a 90 minute boil?
Post by: mabrungard on May 16, 2011, 09:44:19 PM
Ninety minutes produces about the maximum isomerization potential for alpha acids in wort according to work by Malawicki and Shellhammer.  Beyond that time, the isomerized alpha acids are broken down to a slight degree and the bittering actually decreases.  In terms of energy efficiency of converting alpha acids to iso-alpha acids, a boil time in the 60 minute range is better than 90 minutes. 
Title: Re: Benefits of a 90 minute boil?
Post by: Pawtucket Patriot on May 16, 2011, 09:56:14 PM
If I'm using pils malt, I'll go 90 minutes to drive off the DMS. I also use a 75 minute boil with non-pils grain bills as well, just so that I have 15 minutes to get the hot break before I add any hops, reducing the risk of boil-over.

+1

If pils is 50% or more of my base malt, I'll boil for 90 minutes to alleviate DMS concerns. Otherwise, I boil for 70 minutes (10-minute hot-break period).
Title: Re: Benefits of a 90 minute boil?
Post by: Will's Swill on May 16, 2011, 11:22:17 PM

Yes, you need to remove enough water for the temperature to get hot enough for the sugars to caramelize.  We never reach that point with wort.  For example, maltose doesn't caramelize until over 350F.  Glucose around 320F.  Wort - 212F.  Your wort might hit 215F though Fred. :)

<edit>I found this cool boiling point calculator.  Enter the brix, it tells you the bp.
http://www.sugartech.co.za/bpe/index.php

Do you not get carmelization at the bottom of the pot?  I would think the bottom would get much warmer than boiling, but not sure how much more...
Title: Re: Benefits of a 90 minute boil?
Post by: tschmidlin on May 16, 2011, 11:32:28 PM

Yes, you need to remove enough water for the temperature to get hot enough for the sugars to caramelize.  We never reach that point with wort.  For example, maltose doesn't caramelize until over 350F.  Glucose around 320F.  Wort - 212F.  Your wort might hit 215F though Fred. :)

<edit>I found this cool boiling point calculator.  Enter the brix, it tells you the bp.
http://www.sugartech.co.za/bpe/index.php

Do you not get carmelization at the bottom of the pot?  I would think the bottom would get much warmer than boiling, but not sure how much more...
Maybe. :)  The pressure won't be sufficient to cause the temperature rise, and it's the sugar that has to be hot enough, not the kettle.  I don't the physics well enough to know for sure.
Title: Re: Benefits of a 90 minute boil?
Post by: Will's Swill on May 17, 2011, 12:34:18 AM
What would happen to fermentability if it did carmelize?  I was recently trying to brew a very small batch to do some mash experiments, and while I used a very low boil, I nevertheless reduced the wort to sludge.  It didn't look or smell burned, but the gravity was off the scale of both my hydrometer and refractometer.  Perhaps I actually made extract.  :P  So I diluted it back to a reasonable gravity and pitched.  But no fermentation.  If I thoroughly carmelized the wort, would that remove the fermentables?
Title: Re: Benefits of a 90 minute boil?
Post by: tschmidlin on May 17, 2011, 05:58:12 AM
What would happen to fermentability if it did carmelize?  I was recently trying to brew a very small batch to do some mash experiments, and while I used a very low boil, I nevertheless reduced the wort to sludge.  It didn't look or smell burned, but the gravity was off the scale of both my hydrometer and refractometer.  Perhaps I actually made extract.  :P  So I diluted it back to a reasonable gravity and pitched.  But no fermentation.  If I thoroughly carmelized the wort, would that remove the fermentables?
Fermentability goes down as the sugars caramelize.  I really can't say for sure what you did though. :)
Title: Re: Benefits of a 90 minute boil?
Post by: sharg54 on May 17, 2011, 06:40:22 AM
Quote
Ninety minutes produces about the maximum isomerization potential for alpha acids in wort according to work by Malawicki and Shellhammer.  Beyond that time, the isomerized alpha acids are broken down to a slight degree and the bittering actually decreases.  In terms of energy efficiency of converting alpha acids to iso-alpha acids, a boil time in the 60 minute range is better than 90 minutes. 
Quote
Longer boils tend to darken the wort and there are maillard reactions taking place producing more melanoidins that enhance the maltiness of the wort. Not to mention increased hop isomerization or enhanced hop bitterness. The longer boil also concentrates these flavors that are created during the boil. Driving off DMS is probably one of the biggest reasons to boil longer but these other attributes also come into play as well.
Ok this is a bit over my head so if this don't come out right what can I say. So can I assume if I employ a longer boil of 90 minuets to bring out the flavors of the malt and don't start adding the hops until the last 60 minuets of the boil I can have the best of both worlds?
Title: Re: Benefits of a 90 minute boil?
Post by: tschmidlin on May 17, 2011, 07:23:16 AM
Yes, you can boil as long as you like.  Some historical brews have even boiled overnight.  But if you boil the hops too long you can get a veggie taste, so save them for the last 60-90 minutes.  I don't go over that length, but have never tested it.
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 17, 2011, 11:34:35 AM
Quote
Ninety minutes produces about the maximum isomerization potential for alpha acids in wort according to work by Malawicki and Shellhammer.  Beyond that time, the isomerized alpha acids are broken down to a slight degree and the bittering actually decreases.  In terms of energy efficiency of converting alpha acids to iso-alpha acids, a boil time in the 60 minute range is better than 90 minutes. 
Quote
Longer boils tend to darken the wort and there are maillard reactions taking place producing more melanoidins that enhance the maltiness of the wort. Not to mention increased hop isomerization or enhanced hop bitterness. The longer boil also concentrates these flavors that are created during the boil. Driving off DMS is probably one of the biggest reasons to boil longer but these other attributes also come into play as well.
Ok this is a bit over my head so if this don't come out right what can I say. So can I assume if I employ a longer boil of 90 minuets to bring out the flavors of the malt and don't start adding the hops until the last 60 minuets of the boil I can have the best of both worlds?

Yes.

Longer boil = Maillard reactions = enhanced flavor (maltiness)

Follow a calculated hopping schedule to achieve desired bitterness, flavor and aroma.
Title: Re: Benefits of a 90 minute boil?
Post by: SpanishCastleAle on May 17, 2011, 11:58:21 AM
I've heard/read the 'no caramelization' in the boil before and it all seems to make sense.  But then what is happening when we do a 'kettle caramelization' of the first runnings a la Strong Scotch Ale?  It definitely changes the flavor; a lot, and also changes the mouthfeel; a lot.  It kind of tastes like caramel.  So what happened?

blatz tasted my SSA in the Hurricane Blowoff.  That was just base malt and a little roasted barley for color.  All the 'caramel' flavor and a lot of the mouthfeel was from kettle 'caramelization'.
Title: Re: Benefits of a 90 minute boil?
Post by: hopfenundmalz on May 17, 2011, 12:27:15 PM
Caramelization happens at elevated temps.  This only happens when you have boiled off most of the water.  It starts at 230F and must go higher for some of the larger sugar chains, > 300F.

So if you boil down first runnings in the kettle or a pan you can caramalize.  If you boil all the wort at ~212F, you don't caramelize.  Are there elevated temps at the metal-liquid interface that can cause small amounts of caramelization?  That I don't know.
Title: Re: Benefits of a 90 minute boil?
Post by: weithman5 on May 17, 2011, 01:10:06 PM
would you get some carmalization during a decoction ie if you basically fried the pulled part?  and are any of the sugars carmalized during kilning at high temperatures?
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 17, 2011, 01:21:37 PM
would you get some carmalization during a decoction ie if you basically fried the pulled part?  and are any of the sugars carmalized during kilning at high temperatures?


I would love to test the kettle caramelization theory someday.

Can a decoction be thick enough to enable the caramelization mechanism to occur?  I believe it's possible but the grain may get scorched.  :-\

I believe the decoction would have to be really thick almost to the point of a doughball to enable the sugars to caramelize.
Title: Re: Benefits of a 90 minute boil?
Post by: stlaleman on May 17, 2011, 01:29:42 PM
  and are any of the sugars carmalized during kilning at high temperatures?


That is how crystal malts are made. Wet malt is heated before drying to create the caramel/toffee flavors.
Title: Re: Benefits of a 90 minute boil?
Post by: ccarlson on May 17, 2011, 01:37:43 PM
would you get some carmalization during a decoction ie if you basically fried the pulled part?  and are any of the sugars carmalized during kilning at high temperatures?


I would love to test the kettle caramelization theory someday.

Can a decoction be thick enough to enable the caramelization mechanism to occur?  I believe it's possible but the grain may get scorched.  :-\

I believe the decoction would have to be really thick almost to the point of a doughball to enable the sugars to caramelize.

IMO you carmelization with a thick decoction.
Title: Re: Benefits of a 90 minute boil?
Post by: bonjour on May 17, 2011, 04:34:42 PM
  Are there elevated temps at the metal-liquid interface that can cause small amounts of caramelization?  That I don't know.
Without doubt there are elevated temps at the metal-liquid interface.  I have not been able to determine what these temps are/will be.  Without a doubt the liquid wort/water will be at boiling temp, approx. 212F, in the kettle.  Without doubt there is no caramelization there.  There are issues commercially  with removing heat with liquid from metal-liquid interfaces, and they have been in the news recently (the reactors in Japan).  Different application but some of the same thermodynamic issues.
Scientifically it has never been proven that caramelization occurs in beer production. If it does it occurs on a micro level, and as I said there is no proof that this occurs.
Title: Re: Benefits of a 90 minute boil?
Post by: narcout on May 17, 2011, 09:43:47 PM
Scientifically it has never been proven that caramelization occurs in beer production.

Is that inclusive or exclusive of the process of boiling down a small portion of the first runnings into a thick syrup?
Title: Re: Benefits of a 90 minute boil?
Post by: ccarlson on May 17, 2011, 09:57:21 PM
Scientifically it has never been proven that caramelization occurs in beer production.

Is that inclusive or exclusive of the process of boiling down a small portion of the first runnings into a thick syrup?

As with making candy or boiling wort, once the water is minimized, carmelization will occur. I have boiled down a gallon of wort slowly and it got very dark. Of course it also very concentrated. The trick is to not rush it or it will burn. If that happens, it's only fit for the trash.
Title: Re: Benefits of a 90 minute boil?
Post by: sharg54 on May 18, 2011, 12:37:44 AM
 Very good topic.  ;D Going to have to do a test batch at an extended boil with a known recipe and see how it turns out compared to the normal way I make it.
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 18, 2011, 02:25:46 AM
Scientifically it has never been proven that caramelization occurs in beer production.

Is that inclusive or exclusive of the process of boiling down a small portion of the first runnings into a thick syrup?

If the temp was 230F or higher, only then would you have some caramelization. It would have to be pretty viscous. I've boiled down wort to a thick "molasses like" consistency but didn't measure the temp. Next time I'll have to remember to do that.
Title: Re: Benefits of a 90 minute boil?
Post by: ccarlson on May 18, 2011, 03:17:47 AM
Scientifically it has never been proven that caramelization occurs in beer production.

Is that inclusive or exclusive of the process of boiling down a small portion of the first runnings into a thick syrup?

If the temp was 230F or higher, only then would you have some caramelization. It would have to be pretty viscous. I've boiled down wort to a thick "molasses like" consistency but didn't measure the temp. Next time I'll have to remember to do that.

It will be difficult to get an accurate reading. What you measure in the middle of the wort is not what the wort sees at the actual heated surface.
Title: Re: Benefits of a 90 minute boil?
Post by: paul on May 18, 2011, 03:59:09 AM
Returning somewhat to the original question about the benefits of a 90-minute boil, are there benefits to a longer boil?

I've recently done a series of beers with primarily pilsner malts, and the first two still came out with some DMS, despite a good rolling boil and pretty rapid cooling with immersion chiller.  As I pondered this with a few people from my homebrew club, one or two of them suggested they typically boil even longer than 90 minutes, close to 2 hours, for pils-malt beers.  Note that we are at 5,000 ft, and wort boils at 203, not 212 F.  At least one person's perspective was that at this lower temp, it takes longer to drive off the DMS precursors.

Also, this wiki http://www.homebrewtalk.com/wiki/index.php/Dimethyl_sulphide (http://www.homebrewtalk.com/wiki/index.php/Dimethyl_sulphide) a 100-minute boil is suggested for DMS elimination.  I assume this is for sea level.

I can report that my first to pils-malt beers, boiled for 90 minutes, have some DMS, but my third beer, boiled for 105 minutes does not. 

Does anyone have any thoughts about this?  Is 90 minutes enough, particularly at higher elevations?
Title: Re: Benefits of a 90 minute boil?
Post by: tschmidlin on May 18, 2011, 06:00:23 AM
It is very likely to take longer at lower temps (higher altitude), but I have no experience with anything above 500ft so I couldn't say how long you'll need.  90 minutes is long enough for me at 500ft though.
Title: Re: Benefits of a 90 minute boil?
Post by: gordonstrong on May 18, 2011, 10:57:23 AM
How do you "scientifically prove" caramelization has occurred?  Is there some lab technique involved?

I guess I'm less concerned with the explanation as I am with the outcome.  If you boil your first runnings hard when making a Scotch ale, you get more caramel flavors.  These aren't the same flavors I get when I boil a decoction; those are a richer maltier flavor.  Debate how they happen (the Maillard process isn't well described, so good luck), but not that the results occur.

I just wouldn't want people to start drawing the wrong conclusions, like "I heard you can't get caramelization when boiling, so I can't get caramel flavors that way."
Title: Re: Benefits of a 90 minute boil?
Post by: ccarlson on May 18, 2011, 11:18:51 AM
How do you "scientifically prove" caramelization has occurred?  Is there some lab technique involved?

I guess I'm less concerned with the explanation as I am with the outcome.  If you boil your first runnings hard when making a Scotch ale, you get more caramel flavors.  These aren't the same flavors I get when I boil a decoction; those are a richer maltier flavor.  Debate how they happen (the Maillard process isn't well described, so good luck), but not that the results occur.

I just wouldn't want people to start drawing the wrong conclusions, like "I heard you can't get caramelization when boiling, so I can't get caramel flavors that way."

+1

Those sure are "carmel like" flavors I get when I do a boil down.
Title: Re: Benefits of a 90 minute boil?
Post by: bluesman on May 18, 2011, 11:27:24 AM
How do you "scientifically prove" caramelization has occurred?  Is there some lab technique involved?

Good question Gordon. The answer is not straight forward and I believe caramelization is far too complex and a poorly understood process that produces hundreds of chemical products. The following are some of the reactions:

equilibration of anomeric and ring forms
sucrose inversion to fructose and glucose
condensation reactions
intramolecular bonding
isomerization of aldoses to ketoses
dehydration reactions
fragmentation reactions
unsaturated polymer formation.

So...now that we got that monkey off our backs we can now imagine how we get that caramel flavor in our beer.  ;D
Title: Re: Benefits of a 90 minute boil?
Post by: narcout on May 18, 2011, 11:29:40 PM
Those sure are "carmel like" flavors I get when I do a boil down.

Yeah, it definitely adds some flavor.  To me, it tasted like butter toffee. 

If you boil your first runnings hard when making a Scotch ale, you get more caramel flavors.  These aren't the same flavors I get when I boil a decoction; those are a richer maltier flavor.

Do you have any insight into how the flavor you get from boiling down the first runnings compares to what you would get if you did an extended 3 or 4 hour full wort boil?