High altitude boiling

[billpaustin]

Wiki says:
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For home cooking, this effect becomes relevant at altitudes above approximately 2000 feet (600 m). At that altitude, water boils at approximately 208ºF (98ºC) and adjustments sometimes need to be made to compensate for the reduced air pressure/water boiling point.
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I'm at 8,000 feet, and wondering if I need to compensate. Water boils at 195 or so, here, according to the chart. So, just boil longer?

edit: could this explain why my stout is at 1.040OG instead of the expected 1.053? Not boiled enough?

 

[Reef]

My fist brew, a hefeweizen, finished at 1.026 instead of 1.014. It fermented at 72 ambient temp, higher than I planned.

My second batch, an oatmeal stout finished at 1.016, exactly where I planned with a good fermentation temp. About 63.

In at 5600 ft.... I think process has more to do with it than altitude, but I'm fairly new... 15 gallons down so far.... take my advice with a grain of salt.

 

[tommysauder]

OP was stating OG not FG

 

[Reef]

My bad... did you do late water additions to account for boil off?

 

[microbusbrewery]

could this explain why my stout is at 1.040OG instead of the expected 1.053? Not boiled enough?

Boiling at higher altitudes where the atmospheric pressure is lower compared to sea level would actually result in an increased evaporation rate. So you're stout should have had higher than expected gravity, not lower.

Are you doing all-grain or extract?

 

[TANSTAAFB]

I'm at about the same altitude and all I noticed moving from around sea level is it takes less time to get to a boil and I have a big boil off if I don't turn the flame down. I don't believe you have to boil longer. I just start my timer when it hits a rolling boil like anyone else!

 

[billpaustin]

I'm doing a grain soak, and then dry malt extract. I did add water after the boil, since it seemed like a lot had boiled off. Next time, I'll measure I added more than a gallon, almost 1 1/2 gallons. Probably too much.

After sitting all night, it is starting to bubble, and looks and smells good. I pitched the yeast when it had cooled to 75, and this morning, it is at 69. Hope that's not too hot for a stout. My other fermenter is at 64, so I bet the stout will cool off some more.

 

[microbusbrewery]

Yeah, you may have topped it off with too much water and diluted it too much. Or if you didn't stir the water in real well you may have gotten a bad reading (denser wort on the bottom, less dense on the top).

 

[billpaustin]

Yeah, you may have topped it off with too much water and diluted it too much. Or if you didn't stir the water in real well you may have gotten a bad reading (denser wort on the bottom, less dense on the top).

By "too much dilution" you don't mean that it is bad? It should turn out fine, but perhaps a little low in ABV, right?

 

[funkphiler]

Adding too much water will give your beer less body. It will taste about the same just a bit watery. This happens at the brewpub in my town, I think for some of their beers they water it does to make a bit more money... However the problem with you F.G. to me is more the fact that your water is not at 212 and therefore does not have the same capability to dissolve the sugar. What I would do is keep a lid over you pot while you boil. This should allow you boil to reach the 212 necessary as the reason you boil at a lower rate is due to less pressure pushing down of your liquid. Putting a lid over it will cause the vapor from your boil to build up and increase the temp... Make sure to watch out for boil overs if you do this.
If you choose to go without the lid boil for longer and stir a lot and you will see the same effect... just takes a bit more time. Hope this helps

 

[Beernik]

I'm at 5500 feet

Also with lower boiling temperature you get lower hop utilization, which means lower IBU. The Garetz method uses an elevation factor.

With that said, I've never worried about making corrections for elevation

 

[ColoradoJon]

Please don't boil your wort with the lid on the pot...

I'm at 8500 feet and have noticed no difference whatsoever in OG/FG. Hop utilization, like Beernik said, might be affected but I don't worry about it.

 

[Walking_Target]

Getting into the garetz method is kinda silly for just a couple degrees difference. As i remember, most of the alpha acids will isomerize (form bittering compounds) at around 170*f to 190*f.

They do it a touch more slowly at that temperature though, so you should consider adding a few minutes earlier in the boil for bittering, but don't change your late aroma and flavor additions, different compounds being extracted there.

You can also compensate by adding 5% to 10% more hops.

Really, the best thing to do will be to try a couple batches and see what happens. Once you hit a recipe you like, run with it.

 

[bob1852]

Please don't boil your wort with the lid on the pot...

I'm at 8500 feet and have noticed no difference whatsoever in OG/FG. Hop utilization, like Beernik said, might be affected but I don't worry about it.

Yes, this.

There's quite a bit of bad information in this thread, but this is spot on.

I'm at 7,000 feet and agree completely.

If you have bitterness problems, look at increasing the sulfate in your water.

 

[billpaustin]

Yes, this.

There's quite a bit of bad information in this thread, but this is spot on.

I'm at 7,000 feet and agree completely.

If you have bitterness problems, look at increasing the sulfate in your water.

I'm using all rain-water, my whole house is off of rain water, so it is very soft and no chemicals or minerals. I'm going to have to study up if I ever have to change the water properties.