Is boiling wort same as boiling water?

[Smellyglove]

I did some searches, and got different answers.

So, easy question maybe not so easy answer.

This is regarding getting some data from my new kettle when it comes to boil off.

 

[feinbera]

It's close enough as far as estimating boil-off times/rates goes.

 

[TheZymurgist]

It sounds like you're asking whether you can measure your boil off rate by testing it with water, correct? If so, then I would say yes. There may be some differences between the evaporation rates of wort and water, but I would think that on our scale, it's too minimal to have any effect.

 

[funnycreature]

Another interesting aspect in determining the boil-off rate is the expansion factor. Beersmith accounts for the loss in volume due to the cooling of the wort ("shrinkage"). It's supposedly only 4% but I'm a bit confused by exactly how this is determined. There seem to be a few inaccuracies in my measuring process:

• I measure the cold water before heating it to strike/sparge temp
• I take the pre-boil volume at mash temp (140-160 F)
• I measure the volume during the boil at ~212 F, also affected by the rolling boil.

Not sure if I really have a question here but I'd like to know how other brewers account for the temperature when they measure their volumes.

Cheers

 

[Smellyglove]

Another interesting aspect in determining the boil-off rate is the expansion factor. Beersmith accounts for the loss in volume due to the cooling of the wort ("shrinkage"). It's supposedly only 4% but I'm a bit confused by exactly how this is determined. There seem to be a few inaccuracies in my measuring process:

• I measure the cold water before heating it to strike/sparge temp
• I take the post-boil volume at mash temp (140-160 F)
• I measure the volume during the boil at ~212 F, also affected by the rolling boil.

Not sure if I really have a question here but I'd like to know how other brewers account for the temperature when they measure their volumes.

Cheers

Yes. I know about this, I think for my previous kettle I upped the 4% just a little bit.

When it comes to cooling shrinkage i feel I should measure it with actual wort, since it's denser.

The method I used to determine my shrinkage factor (George costanza anyone?) was that after flame out I put the lid on and started cooling. Took a note of volume before and after cooling. I only did this once, so I have no idea if it relative to the wort volume.

 

[funnycreature]

Yes. I know about this, I think for my previous kettle I upped the 4% just a little bit.

When it comes to cooling shrinkage i feel I should measure it with actual wort, since it's denser.

The method I used to determine my shrinkage factor (George costanza anyone?) was that after flame out I put the lid on and started cooling. Took a note of volume before and after cooling. I only did this once, so I have no idea if it relative to the wort volume.

I just noticed (and corrected) a mistake in my post: it should read pre-boil, not post-boil. Either way, I don't think that I want to invest too much time and effort (and energy cost) into determining the shrinkage factor. However, I should really get my number for boil-off since I'm always struggling with my OG or volume... I just don't get enough time brewing so I don't want to "waste" some of that time with measuring

 

[Smellyglove]

I just noticed (and corrected) a mistake in my post: it should read pre-boil, not post-boil. Either way, I don't think that I want to invest too much time and effort (and energy cost) into determining the shrinkage factor. However, I should really get my number for boil-off since I'm always struggling with my OG or volume... I just don't get enough time brewing so I don't want to "waste" some of that time with measuring

Get a copper pipe, mark it, and keep it in there. Easy

 

[funnycreature]

Get a copper pipe, mark it, and keep it in there. Easy

I actually have a metal ruler that I use to calculate the volume from All I need to do is type the height of the liquid into my Excel template and I get the volume

 

[pjfallat]

For a 5 gallon post boil batch a 4% shrinkage is .8qts. Add 1 extra qt of water to your preboil volume to counteract the shrinkage

 

[Smellyglove]

I'm pulling this one up.

I've reinsulated my kettle with thinner insulation and I'm getting a low boil off. With water.

When you boil wort you get this layer of foam on top. Can it be that this layer insulates and gives you a harder boil?

 

[Smellyglove]

Anyone?

 

[Wolfbayte]

The method I used to determine my shrinkage factor (George costanza anyone?) was that after flame out I put the lid on and started cooling. .

It shrinks? I don't know how you guys walk around with those things.

 

[Smellyglove]

Whenever you eat a cheezedoodle...

On topic:

Double boiloff with wort than water. (in my setup)

For people who might google the same question