Going above 212*F/100*C during boil

[pmicka]

I recently started my first brew, a Bavarian Weissbier kit from my local HBS, and had a question regarding the temperature at which I boiled my wort. I used a 23-Quart Aluminum canning pot, which in and of itself isn't notworthy. However, the range in my apartment is quite small and it was a challenge getting the water to a rolling boil. To speed things up I put the lid on the pot and it was boiling in no time, I ended up repeating this for a few minutes to get the wort back to a boil after I had thoroughly mixed in the first tub of LME. With the lid on the temps easily surpass 212 degrees fahrenheit and I'm wondering what impact this might have on the beer.

The beer has been fermenting at a steady 68-70 degrees and after about 6 days I'm still seeing a bubble in the airlock every minute or so.

I'm not really too concerned that I've negatively influenced the taste in such a way as to make it undrinkable, just curious.

 

[atom]

your wort did not go above boiling temp (212ish)...once you do it evaporates.

 

[Zixxer10R]

Well, your boiling wort didn't actually surpass boiling temps (205-215 depending on sea level and humidity). Your lid surely did, but that's because aluminum's boiling point is MUCH higher than 212°.

You did ferment a little high though, how are you controlling your ferm temps? either way, it's going to beer that you will drink.

 

[spokaniac]

There may be a degree plus or minus difference due to the specific gravity or your altitude above sea level, but unless you seal the lid and pressurize it, you aren't going to get significantly hotter than 212 in the wort itself.

 

[pmicka]

@atom, a canning pot, aka a pressure cooker, enables temps above 212 degrees.

@Zixxer, due to a mild winter and my aversion to turning on the heat the temp is kept stable at 68/70 degrees without any action taken by me. Not optimal, but it will do for now.

The lid was "on" but not sealed, so it was essentially just the weight of the lid keeping any pressure in. I estimate that at the low end of the PSI/Temp scale it reached 220 degrees for no less than 5 minutes.

 

[DeafSmith]

The lid was "on" but not sealed, so it was essentially just the weight of the lid keeping any pressure in. I estimate that at the low end of the PSI/Temp scale it reached 220 degrees for no less than 5 minutes.

For the temperature to reach 220º F, you would have to have a total pressure of a little over 17 psi, or over 2.3 psi above sea level atmosphere:

http://www.engineeringtoolbox.com/boiling-point-water-d_926.html

If your pot or kettle is, for example, 10 inches in diameter, with an area of 78.5 square inches, then it would take a force of (2.3)(78.5) = 180.6 pounds to hold the lid closed and maintain the wort at 220ºF. Unless your lid weighs 180 pounds (assuming 10 inch diameter), your wort did not reach 220º. Even the fact that this is a sugar solution and not pure water doesn't significantly raise the boiling point.

http://chestofbooks.com/food/scienc...The-Boiling-Point-Of-Water-And-Solutions.html

From the above, you can see that even with a 30% sugar solution, the boiling point is only increased by 1º C, or less than 2º F.

If you measured the temperature of the vapor inside the closed pot, maybe it could have been at 220º F, but it's more likely that your thermometer is not accurate.

 

[pmicka]

@DeafSmith The 220 was just an estimate. Like I said, I'm not really worried about having ruined the beer. I'm mostly interested in knowing what impact this raised temperature would have on the wort (sugars, enzymes, etc). I'm not really interested in knowing the exact temperature my wort coulda/woulda/shoulda been at if it were travelling on a train going 100mph at sea level on a leap year.

 

[atom]

in that case, it had no impact.

 

[mcarb]

It sounds like you know the answer you are looking for and don't really want input.

It destroyed your wort by breaking down enzymes normally used by yeast.

Is that the answer you want?


Well if so, it's not true.

 

[pmicka]

@mcarb If had known the answer I wouldn't have asked the question. I'm not sure what I've said to make you assume otherwise, but I digress and what's done is done. Maybe if I rephrase my question in purely theoretical terms I won't give off the impression that I'm a jackass by asking a completely reasonable question.

Theoretically speaking, what effect would temperatures in excess of 212 degrees fahrenheit have on wort?

 

[BrewKnurd]

@DeafSmith The 220 was just an estimate. Like I said, I'm not really worried about having ruined the beer. I'm mostly interested in knowing what impact this raised temperature would have on the wort (sugars, enzymes, etc). I'm not really interested in knowing the exact temperature my wort coulda/woulda/shoulda been at if it were travelling on a train going 100mph at sea level on a leap year.

I think the point that Deafmsith was making was that your temperature was not above 212 in any meaningful (or possibly, depending on your thermometer, even measurable) way.

So you should worry about as much about any temperature elevation experienced as a result of your lid as you do about your train example. Neither of them matter. For all intents and purposes, you did not experience any higher temp as a result of the lid being on, because you did not increase the pressure by any meaningful amount.

 

[passedpawn]

@mcarb If had known the answer I wouldn't have asked the question. I'm not sure what I've said to make you assume otherwise, but I digress and what's done is done. Maybe if I rephrase my question in purely theoretical terms I won't give off the impression that I'm a jackass by asking a completely reasonable question.

Theoretically speaking, what effect would temperatures in excess of 212 degrees fahrenheit have on wort?

None. It's been said in this thread already.

Guys put canned wort (mason jars typically) in pressure cookers all the time to sterilize, then use as wort for making yeast starters later. (which reminds me, check craigslist for a big pressure cooker).

They are probably hitting 250F+ in the cooker. Wort still ferments.

 

[bessieflames]

I would be more concerned with the fact that you had the lid on during the boil. LIDS STAY OFF! Nobody likes cooked cabbage.

 

[BrewKnurd]

So elevated wort boiling temp probably would result in darker wort due to increased browning reactions. In addition, you would isomerize alpha acids quicker, I think, but you would also degrade isomerized alpha acids faster, so I don't know how that would net out.

 

[Skagdog]

You may also want to look for a canning element for you stove. That element puts out a bit more heat and is usually beefed up to support more weight. It's a simple, unplug the old one plug in the new one, swap that MAY make boiling a little easier..

 

[pmicka]

Thanks! I was made aware of how the temp would affect the hops after reading some of Papazian's book a day or two ago and had wondered about the effect extreme temps would have on the wort and how that might compare to the effects of an extended boil.

@passedpawn: This is the canning pot/pressure cooker I use and couldn't be happier with it: http://www.amazon.com/dp/B0000BYCFU/?tag=skimlinks_replacement-20

 

[passedpawn]

I would be more concerned with the fact that you had the lid on during the boil. LIDS STAY OFF! Nobody likes cooked cabbage.

I don't think DMS is an issue with extract.

 

[Yooper]

I don't think DMS is an issue with extract.

I think it can be- I've had some "cabbage" beers in competition, and I'm certain they were extract. Whether it came from the boil, or somewhere else, I can't say. But I definitely tasted DMS in a few extract brewers' entries!

 

[NordeastBrewer77]

Thanks! I was made aware of how the temp would affect the hops after reading some of Papazian's book a day or two ago and had wondered about the effect extreme temps would have on the wort and how that might compare to the effects of an extended boil.

@passedpawn: This is the canning pot/pressure cooker I use and couldn't be happier with it: http://www.amazon.com/dp/B0000BYCFU/?tag=skimlinks_replacement-20

ok, here's what happened. when you had the lid on, the steam coming off the wort (which is boiling, steam is what happens when liquid reaches boiling) was building up in the headspace. this generates more heat. the reason your temp read high is the same reason you put the lid on in the first place, it creates a hotter environment. if you were to uncover the kettle, move the thermometer around a few times, it would read the actual temp of the wort.

FWIW, water can't reach a temperature above it's boiling point unless it's given special conditions. when it reaches it's boiling point, it's no longer water, it's steam, a gaseous form of H2o.

 

[jeepinjeepin]

I think it can be- I've had some "cabbage" beers in competition, and I'm certain they were extract. Whether it came from the boil, or somewhere else, I can't say. But I definitely tasted DMS in a few extract brewers' entries!

So. After the wort is condensed/dehydrated and then reconstituted it still contains SMM/DMS and should be cooled quickly just like AG?

 

[bessieflames]

I don't think DMS is an issue with extract.

I re-read the OP. I missed that it was a kit. I don't think DMS is a big problem with extracts, but there are other reasons not to put the lid on such as boil-overs. It just doesn't seem like a good practice.

 

[Ultra-Medic]

I re-read the OP. I missed that it was a kit. I don't think DMS is a big problem with extracts, but there are other reasons not to put the lid on such as boil-overs. It just doesn't seem like a good practice.

Been there. Lids will result in boil overs. First batch held a near-boil at 190-200 degrees. Was 5gal on electric coil stove. Turned on the second burner, decided to add the lid... spent the next morning learning what cleans burned wort from a stove.

End result? Awesome brown ale. So don't worry so much and be patient.

 

[passedpawn]

a harder boil simply means faster evaporation of the water.

To be specific, it's vaporization, not evaporation (well, maybe a little evaporation, but it's not significant in this case). The reason I point this out is because when you get into the math of it, "heat of vaporization" is what is driving the water into the air. For electrical brewers, things can be surprisingly (pleasantly!) mathematical and deterministic. Evaporation happens at the surface, and is subject to dew point and other ambient effects, while vaporization is driven from the bottom (flame) or the element.

(I'm not trying to start a fight here, just want to make sure the terms are correct... I know what you meant).

 

[MuchoGusto]

As a former high school science teacher, steam is a technical term for water water vapor.

 

[passedpawn]

As a former high school science teacher, steam is a technical term for water water vapor.

Mr. Tremble? (my HS chemistry teacher, great guy, one of the greats that made me)

 

[pelipen]

Impurities raise the boiling point and lower the freezing point of a pure substance. you can calculate how much table sugar would be required to increase the boiling point by 1 C. It's going to come out to be a huge amount.
Two things are true:
1) the boiling point of wort is higher than 212 F at one atmosphere.
2) it's totally insignificant

You can boil water in a paper cup. You can also burn a hole in a paper cup with water in it. How you measure matters.

 

[BrewKnurd]

Impurities raise the boiling point and lower the freezing point of a pure substance. you can calculate how much table sugar would be required to increase the boiling point by 1 C. It's going to come out to be a huge amount.
Two things are true:
1) the boiling point of wort is higher than 212 F at one atmosphere.
2) it's totally insignificant

According to this handy-dandy calculator, a 1.048 wort would experience a boiling point elevation of a whopping 0.5 degrees celsius!

 

[jeepinjeepin]

To be specific, it's vaporization, not evaporation (well, maybe a little evaporation, but it's not significant in this case). The reason I point this out is because when you get into the math of it, "heat of vaporization" is what is driving the water into the air. For electrical brewers, things can be surprisingly (pleasantly!) mathematical and deterministic. Evaporation happens at the surface, and is subject to dew point and other ambient effects, while vaporization is driven from the bottom (flame) or the element.

(I'm not trying to start a fight here, just want to make sure the terms are correct... I know what you meant).

Latent heat of vaporization.

 

[passedpawn]

Latent heat of vaporization.

right. I don't remember the number, but it's an easy conversion from watts to know how much water gets vaporized per minute/hour from a 5500W element.

I'm too lit to do the math. I've done it before on here, to a huge round of silent applause (ugh). One of the joys for electric brewers is the absolute predictability of the system.

 

[jeepinjeepin]

right. I don't remember the number, but it's an easy conversion from watts to know how much water gets vaporized per minute/hour from a 5500W element.

I'm too lit to do the math. I've done it before on here, to a huge round of silent applause (ugh). One of the joys for electric brewers is the absolute predictability of the system.

It's amazing what you can do with hard numbers. With your wattage, ambient temp, humidity, etc you could exactly figure boil off among other things.