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Carmelization Effecting SRM

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jrfehon

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I'll start by stating that I do all grain stove top brewing. I have a gas stove. I'm having an issue with the color of my beers. All my beers seem to be darker than they should. My best guess is that since I don't get a vigorous rolling boil the heat is caramelizing the wort. I have been doing 90 minute boils with some of my beers. Maybe I should only do 60 minute boils? I have also thought about rigging some sort of an electric mixer to my brew kettle to create more movement of wort. Does anyone else have this problem or any ideas on how I can correct this to get better color? I simply don't have the capability to brew outside with a turkey burner.
 
I'll start by stating that I do all grain stove top brewing. I have a gas stove. I'm having an issue with the color of my beers. All my beers seem to be darker than they should. My best guess is that since I don't get a vigorous rolling boil the heat is caramelizing the wort. I have been doing 90 minute boils with some of my beers. Maybe I should only do 60 minute boils? I have also thought about rigging some sort of an electric mixer to my brew kettle to create more movement of wort. Does anyone else have this problem or any ideas on how I can correct this to get better color? I simply don't have the capability to brew outside with a turkey burner.

It doubt a higher BTU burner will reduce Carmelization if that is what you are actually getting. More likely it is the Maillard Reaction discussed at length in a recent thread and in the past on Extract brewing threads.

Also, it is possible there is some variation from various malsters and year over year for the same malt if you variance is minor.
 
It doubt a higher BTU burner will reduce Carmelization if that is what you are actually getting. More likely it is the Maillard Reaction discussed at length in a recent thread and in the past on Extract brewing threads.

Also, it is possible there is some variation from various malsters and year over year for the same malt if you variance is minor.

Thanks for the tip, I'll look into Maillard Reaction. I'm not looking to get a higher BTU burner. My thought was to get something to constantly mix the wort so the liquid at the bottom of the pot doesn't sit and get caramelized.
 
Not sure why your SRM is higher, could well be from kettle reactions in your setup. Do you have any gooey residue stick to the bottom?
How do you measure/compare the SRM?

Putting some (flameproof) insulation around the kettle will help reduce heat loss through the side and may be enough to keep the boil more rolling.

I guess you realize a good rolling boil is needed. When you measure the temps on the top of the wort, is it 212F all around or only in the center?

How large of a volume do you boil? Can you split it over 2 pots (and 2 burners). Like 4+3 or 5+2 gallons. When I boiled on the stove I always split in 5 and 2 and had to leave the lid on the 5 partially (50%) to retain a solid rolling boil. Never had any DMS issues.

Some people use a 1000-1500W heat stick to get the extra BTUs in the wort.
 
Not sure why your SRM is higher, could well be from kettle reactions in your setup. Do you have any gooey residue stick to the bottom?
How do you measure/compare the SRM?

Putting some (flameproof) insulation around the kettle will help reduce heat loss through the side and may be enough to keep the boil more rolling.

I guess you realize a good rolling boil is needed. When you measure the temps on the top of the wort, is it 212F all around or only in the center?

How large of a volume do you boil? Can you split it over 2 pots (and 2 burners). Like 4+3 or 5+2 gallons. When I boiled on the stove I always split in 5 and 2 and had to leave the lid on the 5 partially (50%) to retain a solid rolling boil. Never had any DMS issues.

Some people use a 1000-1500W heat stick to get the extra BTUs in the wort.

No gooey residue. The bottom of my kettle does have a brownish color from brewing. I have to let ez clean sit in there for awhile to remove it.

I measure SRM in Beersmith.

Flameproof insulation is a great idea!

I haven't taken a temperature reading during the boil but it's a good idea.

I do 5 gallon batches. Usually I'll get .5-1 gallon boil off in an hour, so I tend to begin with 6 gallons of wort before a 60 minute boil. I've never split a batch but I should try. When you brewed this way how did you add hops? Did you split 1 ounce into 2 .5oz clumps and add one to each kettle?
 
If you aren't using pilsner malt, try a 30 minute boil for 1 (only one!) batch and adjust your hops to account for the shorter boil. That will quickly tell you if you are getting the darker beer due to the Maillard reaction or if it is just a darker malt.
 
Whether it is caramelization (sugar + heat) or Maillard reaction (sugar + heat + amino acids) the hotter you get it and the longer it stays hot the more color you will develop. Be sure to do full length boils and make them as short as possible if you want to avoid color development. Some brewers add metabite to the kettle to minimize this.
 
I really think based on your information that this is a malt issue...any chance the malster has a posting of its actual spec's for what you bought? Barely a rolling boil and no hint of scorching. All light colored malts. Something just does not add up.

Are the differences subtle or significant?
 
No gooey residue. The bottom of my kettle does have a brownish color from brewing. I have to let ez clean sit in there for awhile to remove it.

I measure SRM in Beersmith.

Flameproof insulation is a great idea!

I haven't taken a temperature reading during the boil but it's a good idea.

I do 5 gallon batches. Usually I'll get .5-1 gallon boil off in an hour, so I tend to begin with 6 gallons of wort before a 60 minute boil. I've never split a batch but I should try. When you brewed this way how did you add hops? Did you split 1 ounce into 2 .5oz clumps and add one to each kettle?

A slight browning is normal as well as some from calcium oxalate (beer stone) precipitating out.

How do you "measure" SRM in BS? It calculates, but how how do you measure the SRM of your wort/beer sample? And what is your reference? A glass of beer appears a lot darker than an SRM sample size. I think judges use 1 inch in a standard tasting cup, not sure, and it's purely qualitative of course, a ballpark.

.5 gallon boil off / hour would be low. 1-1.5 gal is about normal.

When splitting the boil in say 4+2 gallons you do all your additions (salts, hops, spices) proportionally.* Your boil off tends to be higher from the smaller vessel, so keep an eye on that, or start a bit higher, like 3.8+2.2. When the boil is over, combine, chill and rack to fermentor. Or chill separately and rack. Same result.

* weight the hops, but if your scale can't resolve lower weights properly, eyeball the proportional sub-amounts, like 50/50, 40/60, etc.
The easiest is to collect and mix all wort in the main kettle, note your volume, then take out your 2.2 gallons or so for the 2nd vessel boil.

I doubt a mixer will turn the wort over and if it does, you got to watch out for HSA. Stirring will help, but is tiresome while your wort may never really "boil." I'd do the split boil. On a side note, I moved on to a 3500W induction plate, and it does the job better than the glass top stove, without fear of cracking that thing under all that weight.
 
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I really think based on your information that this is a malt issue...any chance the malster has a posting of its actual spec's for what you bought? Barely a rolling boil and no hint of scorching. All light colored malts. Something just does not add up.

Are the differences subtle or significant?

In a typical Pilsner beer (all pale malts) one can see an appreciable deepening in color of the first decoction against the rest mash when it is returned. And again, when the second decoction is returned it is seen to be, against the rest mash, darker still. Further color is developed during the boil. Home brewers kid themselves that they are making beers as light in color as what their spreadsheets calculate for them. I have never been able to produce a beer lighter than 4 SRM and that is with a half hour boil (a Kölsch). So things do indeed add up unless OP is seeing a darkening that is greater than the darkening than is normal. Higher levels of darkening are especially seen in stovetop brewing because often the full length is not boiled and because of the high temperatures associated with stove burners. Boiling with steam gives some reduction in the color produced.
 
A glass of beer appears a lot darker than an SRM sample size.
The cuvet size is arbitrary in measuring SRM. The original procedure specified measurement in half an inch with the absorption multiplied by 10. Today one is more likely to measure with a 1 cm cuvet and multipy by 12.7 but one may, for darker beers, measure in a 5 mm cuvet and multiply by 25.4 or for even darker beers 2 mm and multiply by 63.5 etc.

I think judges use 1 inch in a standard tasting cup, not sure, and it's purely qualitative of course, a ballpark.
When BJCP did the tasting guide I suggested putting 1 cm color patches on one side and 5 cm patches (based on the fact that most beer glasses are about 5 cm in diameter) on the other. To cut costs only one set of patches was done and to be honest I can't remember whether it was 1 or 5 cm. In retrospect 1 cm would have been better as more of the patches would have been in gamut. 'Measuring' SRM by comparison with color patches printed on a card is pretty sketchy considering that two beers with the same SRM may have pretty different colors.
 
Whether it is caramelization (sugar + heat) or Maillard reaction (sugar + heat + amino acids) the hotter you get it and the longer it stays hot the more color you will develop. Be sure to do full length boils and make them as short as possible if you want to avoid color development. Some brewers add metabite to the kettle to minimize this.

To boil as short as you can makes sense to avoid more darkening than necessary. But what exactly do you mean with full length boils in that context and the one you mention below (both highlighted in red)? With some exceptions, isn't 60' for most Pale and 90' for Pilsner malt bases as short as one can do in order to reduce DMS and its precursors?

In a typical Pilsner beer (all pale malts) one can see an appreciable deepening in color of the first decoction against the rest mash when it is returned. And again, when the second decoction is returned it is seen to be, against the rest mash, darker still. Further color is developed during the boil. Home brewers kid themselves that they are making beers as light in color as what their spreadsheets calculate for them. I have never been able to produce a beer lighter than 4 SRM and that is with a half hour boil (a Kölsch). So things do indeed add up unless OP is seeing a darkening that is greater than the darkening than is normal. Higher levels of darkening are especially seen in stovetop brewing because often the full length is not boiled and because of the high temperatures associated with stove burners. Boiling with steam gives some reduction in the color produced.

It's indeed remarkable to see how dark decoctions have become when adding them back to the main mash.

Again, what do you mean with "length" in: "...often the full length is not boiled..." (in red, above) particularly when referring to a stovetop. Isn't a 60' or 90' boil the same, regardless of heat source?

Agreed that steam jackets would be preferred giving the most even heat surrounding the wort. No overheated hot spots on a relatively small area (bottom) as with gas or electric burners with the rest of the pot being mostly an unwanted heat drain (heat sink).
 
The cuvet size is arbitrary in measuring SRM. The original procedure specified measurement in half an inch with the absorption multiplied by 10. Today one is more likely to measure with a 1 cm cuvet and multipy by 12.7 but one may, for darker beers, measure in a 5 mm cuvet and multiply by 25.4 or for even darker beers 2 mm and multiply by 63.5 etc.

When BJCP did the tasting guide I suggested putting 1 cm color patches on one side and 5 cm patches (based on the fact that most beer glasses are about 5 cm in diameter) on the other. To cut costs only one set of patches was done and to be honest I can't remember whether it was 1 or 5 cm. In retrospect 1 cm would have been better as more of the patches would have been in gamut. 'Measuring' SRM by comparison with color patches printed on a card is pretty sketchy considering that two beers with the same SRM may have pretty different colors.

Comparisons between reflected and transmitted light, as with printed patches and a beer sample next to it, is difficult, even more so with darker beers or different hues.

I get better and easier results using the computer screen as the qualitative spectrophotometer, showing the gamut of patches while holding a (Pilsner) sample glass against the white background separating them. Easier to match them up that way. Having a standard cuvet would make that more precise. A glass or clear judging cup is a crude method, and becomes more impractical with darker samples. Then again, once the separation gets murky, shouldn't we just consider it very dark beer. Who really cares beyond that point? Diluting the darkish samples will extend measuring that range. Or using narrower cuvets.

So, back to the OP, how much darker do you think your beer is compared to what BS calculates? And what method do you use to compare?
 
To boil as short as you can makes sense to avoid more darkening than necessary. But what exactly do you mean with full length boils in that context and the one you mention below (both highlighted in red)? With some exceptions, isn't 60' for most Pale and 90' for Pilsner malt bases as short as one can do in order to reduce DMS and its precursors?

This has been the accepted wisdom but I don't think it is true in all instances. When I do a no chill brew I often boil for 45 minutes and then put the lid on to let the wort chill. That should give me plenty of DMS as the wort is still steaming and the steam collects on the lid and drips back into the wort. Yet, I still don't notice any creamed corn taste. Why?

That was one reason that I suggested a 30 minute boil for one time only. If there was DMS, it would be a single instance and the OP would go back to the 60 to 90 minute boil. If there was no DMS, hopefully the OP would take that info and report back. With our modern grains and methods of malting I'm not so sure that DMS is the problem it was in the past.
 
This has been the accepted wisdom but I don't think it is true in all instances. When I do a no chill brew I often boil for 45 minutes and then put the lid on to let the wort chill. That should give me plenty of DMS as the wort is still steaming and the steam collects on the lid and drips back into the wort. Yet, I still don't notice any creamed corn taste. Why?

That was one reason that I suggested a 30 minute boil for one time only. If there was DMS, it would be a single instance and the OP would go back to the 60 to 90 minute boil. If there was no DMS, hopefully the OP would take that info and report back. With our modern grains and methods of malting I'm not so sure that DMS is the problem it was in the past.

Sure, great suggestion worth trying. Today's highly modified malts may indeed not need the longer boil. In the past I had to keep the lid on half way causing condensation to drip back too, but never noticed DMS in the end product either. Still boiled off a gallon an hour or more though.

Now there are still many beer styles that benefit from the kettle reactions and the longer boil. It's the very pale ones that gain too much color, and most noticeably so.
 
To boil as short as you can makes sense to avoid more darkening than necessary. But what exactly do you mean with full length boils
The phrase 'Be sure to do full length boils and make them as short as possible' does seem rather contradictory, doesn't it? The 'length' of a brew is its size e.g. 10 gallons, 10 hL, 10 bbl. Boiling the 'full length' of the brew thus simply means all of it. I was referring specifically to stove top brewing practices in which the full length will not fit into the pot so that concentrated wort is boiled and then dilution water added in the carboy to make up to the 'full length'. This will darken the wort more than a full length boil.

With some exceptions, isn't 60' for most Pale and 90' for Pilsner malt bases as short as one can do in order to reduce DMS and its precursors?
Obviously there is a trade space here. You will note that the Pilner Urquell and Ceske Budejovice type pilsners run around 7 SRM because they are boiled for a long time and have the three (traditionally) decoctions. When I make these beers I boil two hours (and usually get around 7 SRM).




It's indeed remarkable to see how dark decoctions have become when adding them back to the main mash.
...
Isn't a 60' or 90' boil the same, regardless of heat source?
No. A more concentrated wort boiled by a higher temperature heat source will darken more than a more dilute one boiled by a cooler source such as a steam coil. In the extreme case of a high density electric element one can get scorching.
 
I was having a similar issue with SRM being 2 or 3 shades darker on every batch than what the recipe called for.
I started reading about how ph affects malliard reactions, and subsequently the color of your wort.
It has really helped, especially on my kolsch recipe.
 
Comparisons between reflected and transmitted light, as with printed patches and a beer sample next to it, is difficult, even more so with darker beers or different hues.
Part of the problem is that standard CMYK inksets don't have the gamut to cover even fairly light beers in 5 cm. BJCP certainly couldn't afford to have printed their guide with spot colors. And the other problem is color match. The SRM by itself isn't sufficient to describe a beer's color. It takes at least one other number and as many as 3.

I get better and easier results using the computer screen as the qualitative spectrophotometer, showing the gamut of patches while holding a (Pilsner) sample glass against the white background separating them. Easier to match them up that way.
You run into the same gamut problem with a computer screen. It is very limited. Beer colors become very red very quickly as SRM increases and to display them you'd have to have a monitor with a blue gun that can do negative numbers.

Having a standard cuvet would make that more precise. A glass or clear judging cup is a crude method, and becomes more impractical with darker samples.
I found some square bottles that are about 5 cm on a side that I used for some tests (using computer screen comparison).

Then again, once the separation gets murky, shouldn't we just consider it very dark beer.
That depends on the application.

Who really cares beyond that point?
A farbebier manufacturer or a commercial brewer. If his product usually 71 SRM but a batch comes out 61 something has changed.

Diluting the darkish samples will extend measuring that range. Or using narrower cuvets.
You have your choice here. If you dilute (what ASBC and EBC both direct you to do in the case of dark beers) you run the risk that the beer does not follow Beer's Law (I've yet to see such a case) and introduce error in measuring sample and dilutant. OTOH if you use a narrower cuvet you run the risk that the cuvet labeled 2 mm doesn't really have a path of exactly 2 mm.
 
Thanks for all the replies. I measure SRM with Beersmith but then don't measure it again. Looking back at photos of past beers, I have made batches that stayed light, around 4-5 SRM using the same procedures that I do now. It's more recent brews that have darkened. My last batch was a Belgian Tripel that according to Beersmith would have an SRM of 4.3. It ended up around 10. There weren't any off flavors, I was simply an aesthetic issue. I realized that during my brew day for the tripel I didn't vorlof after the first runnings and each batch sparge. Maybe I had extra chunks in my wort that caused the darkening?
 
That means it should have had log absorption of 4.3/12.7 per cm at 430 nm but instead had log absorption 10/12.7 per cm. How do you measure that with a computer program?

To measure the actual SRM I looked at a chart online. Not very scientific but it's clear that my actual SRM is much higher than the 4.3 Beersmith said it would be.
 

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