Wort boiling temps

[starke20]

Hello all,

I have completed two five gallon batches and I have had the wort to a rolling boil of 200 degree Fahrenheit. Does the temp of the wort affect the flavor profile of the beer? Or is there an optimal temp to boil the wort.

 

[KISS Brew]

If it's boiling, it's a set temperature. You can't boil hotter or cooler; that's just not how boiling works. Try to keep your boil vigorous, but as long as it's boiling you're good to go.

I don't know exactly what temperature wort boils at, but I imagine it's closer to 212F than 200F. You might want a new thermometer. The bright side is that I've never needed to know what temperature my boiling wort is at. Ever.

 

[billl]

Sounds like you need to calibrate your thermometer unless you are brewing on the top of a mountain. Liquids boil at a fixed temp and there is nothing you can do to alter that in an open boil.

 

[starke20]

So a rolling boil will not affect the flavor profile. Thanks.

 

[TopherM]

More vigorous boils help with hop efficiency. You want to boil as vigorously as possible without inducing boilovers.

 

[NordeastBrewer77]

Like others have said, maybe check your thermometer's accuracy. The boiling point of water is ~212 F, give or take based on elevation. Highly doubtful your boiling water was only ~200 F, that's most likely due to an inaccurate thermometer.

 

[ludomonster]

If your thermometer isn't accurate, you're going to have problems steeping, mashing, and measuring the wort's gravity.

 

[TheWeeb]

Actually, it is possible that his thermometer is correct; here in Denver water boils at 202 degrees f.; I just looked up the altitude for 200 degree boiling point and found 6,250 ft above sea level.

 

[SMc0724]

Check your elevation before buying a new thermometer. In Denver, water boils at 202 degrees.

A rolling boil is good! Check it out: http://bavarianbrewerytech.com/news/boilhops.htm

At lower temperatures, may need to boil a bit longer, check this out: https://www.homebrewtalk.com/f13/high-altitude-brewing-125401/

 

[AmandaK]

So a rolling boil will not affect the flavor profile. Thanks.

Actually, it will. Rolling boils do not drive off a lot of excess water, which in turn does not concentrate your wort. Boiling hard will concentrate your wort more, creating carmelized flavors.

People get so hung up on the "temperature of boiling" part of your question, they don't even answer your question. Yes, water boils at or less than 212* based on elevation, we get it.

 

[ludomonster]

Carmelization occurs at temperatures above 400F. While it doesn't seem intuitive that you can get that temperature in boiling water, the temperature can have a gradient accross the volume of the wort. Water close to the heat source can become hotter than 212 and travel to the top of the water. In the meantime, it can distribute energy to cooler parts of the volume. The displaced water in turn gets heated and this cycle can continue. Additionally, there is more pressure on the water at the bottom of the boil than there is at the top, which will allow for an increased boiling point. It's probably not a whole lot. And, it depends on the shape and volume of the boil. Almost all of the heat that you apply to the vessel goes directly onto the bottom of the pot. This energy radiates upward according to an inverse square law.

All of this means that the more heat you apply to a boil, the hotter the bottom of the boil will become. That's why slowly stirring in liquid extract is very important to prevent scorching. Furthermore, the boil will become more violent, allowing more steam to escape before its energy can be absorbed by the top of the boil. The splashing may create aerosols, allowing even more water to escape. As the volume falls, there is even less water to absorb heat and the evaporation rate will rise exponentially. As the boil concentrates, the solution's boiling point will rise.

Generally, the best advice is to get a rolling boil with the lowest amount of heat. The rolling boil will agitate the hops and allow for the extraction of alpha acids.

 

[billl]

Carmelization also occurs in dry conditions. There are various browning reactions that occur in hot, wet environments, but they don't give that characteristic carmelization flavor. eg LME darkens as it boils but doesn't really get sweeter.

 

[SMc0724]

Hmmmm...hmmm Superheated wort to 400F. Hmmm...

 

[crazyworld]

Generally, the best advice is to get a rolling boil with the lowest amount of heat.

This ^ . Just make sure you get a good hot break and foaming stops until you've got a stable boil going before adding your hops. Even at my first hops addition, I'm sitting right there by the propane tank turning back to heat or ready to kill it completely until I KNOW I'm not going to boil over.

Chances are, if you're questioning at what temperature water boils, you probably don't live in a place of such high elevation. Where are you?

Best thing to do is get yourself a quality thermometer. If you can calibrate yours, great. If not, you can go one of two ways:

1. Get yourself an oven thermometer (don't submerge the probe too close to the wire!) this way, you can put a set temperature alarm to go off when you hit the temp you want. Set your steeping grains for 155 degrees and walk away (not too far though!). Come back, turn the alarm off, toss the grains in. Use the timer function to set it for 20 or 30 minutes this time. Come back and then set it for 200 degrees (water for me boils at 212). This gives you enough time to hear it going off if you miss it as well as tame any boilovers waiting to happen.

Check out this model sold by Amazon. A good quality thermometer in that style is hard to come by (most complaints tend to come from the probe, so be prepared to replace it) but this is one of the more popular, better rated ones.

http://www.amazon.com/dp/B0019R4HQQ/?tag=skimlinks_replacement-20

2. Just get a quality instant read probe style thermometer and don't stray too far from the pot. The ones in the links below are great because they have the fastest read time for the price at 5 - 6 seconds (they are made by ThermoWorks who make the ThermaPen which has a 3 second readout but costs $90; worth it to some but not me right now), but more importantly for cooking (and sanitation purposes come to think of it) it has a very small probe which is great in the kitchen as you can take accurate temps of very small cuts of meat and without boring a huge hole in it and loosing the natural juices. They're a great investment and very reasonably priced. I own the first one listed but understand it lacks the calibration screw (I don't think I'll need it quite honestly) but the second one has a larger readout (get this is you have crap vision) however, is topheavy and awkward if you were to clip it to an apron or otherwise. I've used both and they're practically the same exact thing, just choose a style based on personal use and preference.

http://www.amazon.com/dp/B002GE2XF8/?tag=skimlinks_replacement-20

http://www.amazon.com/dp/B002GE9S8I/?tag=skimlinks_replacement-20

Edit: I just learned they also make a waterproof version (the other two above are water-resistant which can probably be dunked without adverse effect but you can't depend on more than that). They've also increased the maximum range which is great if you ever do any sort of frying. On top of all of THAT, it's the same price as the other two! The only downside is the tip is a big larger which is a non-issue if you're using it to brew. Order it, or any of the other listed thermometers from the company directly.

http://www.thermoworks.com/products/low_cost/rt600b.html

http://www.thermoworks.com/

 

[HeavyKettleBrewing]

I would think the duration of your boil time will have a greater chance of affecting taste. 60 min boil vs 90 min boil. Personally, I go with a 60min rolling boil and look for the hotbreak. I never measure the temp of the boil for reasons stated before by others. A boil is a boil. Conversely, would the temps required to achieve a boil vary based on pre-boil concentration i.e. 1.052 as opposed to 1.090 or higher?

 

[crazyworld]

A boil is a boil.

I totally glanced over that point in my last post :cross: Granted a good thermometer is what you'll need to hit the right steeping temps, to monitor temps while coming up to a boil and will be ever crucial for your mash should you decide to do all grain. However, most would agree there's a difference between a boil and a rolling boil. Go ahead and temp it though, and you'll find the exact same temperature so it's debatable that it matters at that point. It's likely got to do with increased pressure from th heat although the water cannot get any hotter under the same atmospheric conditions. It's a silly thing really.

Conversely, would the temps required to achieve a boil vary based on pre-boil concentration i.e. 1.052 as opposed to 1.090 or higher?

I really think it's negligible with this amount of dissolved sugars. If we were talking about candy-making, it'd be a whole different thing. Perhaps someone can chime in if they've ever noticed it though, even by a point or two.

 

[HeavyKettleBrewing]

I really think it's negligible with this amount of dissolved sugars. If we were talking about candy-making, it'd be a whole different thing. Perhaps someone can chime in if they've ever noticed it though, even by a point or two.

Funny you should mention candy, it only took a fraction of a second to go from perfect toffee to burnt toffee. I am going to take some temp readings on Sunday brew day. I would be interested to know if boil temps would vary based on gravity. Fact finding will be time consuming given the commitment to a full brew day. If anyone can lend some insight in the interim?

 

[SMc0724]

crazyworld, it is not true "water cannot get any hotter under the same atmospheric conditions," though it's an accepted true statement because it is normal water behavior Water can get superheated without a way to form a steam bubble. This rarely happens, and I cannot see it happening in a regular small batch, hop infused wort, so I doubt that water would experience it, let alone the 400F claimed by billl.

 

[SilverZero]

My wort boils at 213F at 3,500 feet. This has to do with the fact that solutes in water (i.e. sugars) will increase the boiling point, enough to counteract the fact that elevation actually lowers the boiling point a couple of degrees.

One of the biggest benefits of a long, rolling boil is that it drives off DMS. You may not get rid of it if you're just simmering. I think the rule of thumb is that as long as there is some movement from bottom to top, you're fine - no need to keep it jumping out of the pot.

crazyworld, it is not true "water cannot get any hotter under the same atmospheric conditions," though it's an accepted true statement because it is normal water behavior Water can get superheated without a way to form a steam bubble. This rarely happens, and I cannot see it happening in a regular small batch, hop infused wort, so I doubt that water would experience it, let alone the 400F claimed by billl.

Superheating is almost impossible without a very clean vessel with no nucleation sites. This pretty much means glass, probably new glass with no micro scratches in it, and a very specific set of conditions like heating in a microwave. It's not going to happen on a stove top, especially not with a liquid that has sugars and probably a few bits of grain husk or at least a spoon in it. So, yeah, you're right.

 

[crazyworld]

Although you probably understood, more appropriately, I should have said "water cannot boil any sooner under the same atmospheric conditions." Water can boil at room temperature if subjected to a vacuum environment but that is indeed a different atmospheric condition.

I'm not talking about superheating here. I know the phenomenon you're talking about but you're right when you say it rarely happens so lets just disregard it for the time being (if anyone wants to learn/read more about it, look up "boil water microwave explode [or 'superheat']"). Same goes for pressure cookers; we don't want to trap DMS so we're not going to cover the wort so those can be disregarded for our purposes.

I think the remaining question here is whether the dissolved sugars coming from your wort are enough to increase your boiling point, even a little bit. I mentioned candy making because adding sugar to water WILL make the temperature boil beyond its standard boiling point. In fact adding any solute to the water that doesn't vaporize will increase the boiling point; salt is another typical example here.

So technically, yes sugars in your wort will increase your boiling point. Is it a noticeable amount? Maybe. Is it a negligible amount? Definitely. If you're wondering whether your wort is boiling, look at the damn liquid for answers!