[narcout]

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?

[ccarlson]

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.

[sharg54]

 Very good topic.  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.

[bluesman]

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.

[ccarlson]

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.

[paul]

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 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?

[tschmidlin]

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.

[gordonstrong]

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."

[ccarlson]

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.

[bluesman]

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.  

[narcout]

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?