Maybe the dumbest question ever in this forum....

[apexnode]

But why do we boil everything? I'm a newbie that's never brewed a batch other than GF, but why do we boil everything? I do it because everything says so, but:

yeast + sugar = alcohol, right?

Does anything *actually* happen when you boil a sorghum syrup or other fermentable for 60 mins? Isnt boiling because of all grain recipes in non-GF beers and what not?

Couldn't we just put all the fermentables in one container and call it good? Whats the difference?

Thanks for putting me in my place. SCIENCE!

 

[Brewsmith]

Hops need to be boiled.

If you have hopped extract, there's no real need to boil.

 

[KevinM]

Do we? I don't boil anything other than one gallon of water and the hops and spices. If I'm doing extract then I just chuck the syrups into the fermenter and toss on cold water, then the cooled hopped water & yeast and let it ride. Haven't had any issues doing it this way, but I suppose there ought to be a difference between this process and a full boil process since the syrup would wind up being heated.

Okay, I admit that for better fluid dynamics I do heat up the syrup in the microwave (30 seconds or so), but I don't heat it to the extent I would if I were boiling.

I did 2 batches full boil before I got this lazy. I'll do full boil for grain beers though, once I get a recipe I like scaled up.

 

[HopJuicer]

What about hops? They need to be added to the boil at certain times for bittering, flavor and aroma.

 

[igliashon]

It's all about the hops. In mead and cider-making, boils are totally unnecessary, and usually not done. But the thing with hops is, the alpha acids (which are responsible for bitterness) need to be isomerized to become soluble ("isomer" refers to a compounds with the same molecular formula but different structures; those trans fats everyone's talking about are isomers of normal fats, specifically trans-isomers). Boiling isomerizes the alpha acids in hops, and it can take up to 90 minutes to fully isomerize all the alpha acids in a bittering hop addition. The sugars in the wort will affect utilization--i.e. how efficiently you extract the alpha acids from the hops--so boiling without malt/sugars means you can use less hops and get the same IBUs.

 

[allthingsgiant]

Boiling is also because you want to kill any bad bugs in your wort. Probably the most important, too.

 

[igliashon]

You can kill the bugs without boiling. 10-15 minutes at 160°F gets the job done. There's also campden tablets.

 

[olllllo]

The 7 classic reasons to boil. It's on the BJCP exam.
Boiling wort is normally required for the following reasons:

Extracts, isomerizes and dissolves the hop α-acids
Stops enzymatic activity
Kills bacteria, fungi, and wild yeast
Coagulates undesired proteins and polyphenols in the hot break
Evaporates undesirable harsh hop oils, sulfur compounds, ketones, and esters.
Promotes the formation of melanoidins and caramelizes some of the wort sugars (although this is not desirable in all styles)
Evaporates water vapor, condensing the wort to the proper volume and gravity (this is not a primary reason, it's a side effect of the process)

 

[petep1980]

How does one evaporate water vapor? Wouldn't that be like freezing ice?

I wish I was a chemical engineer though and I think understanding all this stuff would be so much easier.

 

[olllllo]

How does one evaporate water vapor? Wouldn't that be like freezing ice?

I wish I was a chemical engineer though and I think understanding all this stuff would be so much easier.

It's not worded all that well, but source: http://www.bjcp.org/study.php

 

[cheezydemon3]

Evaporating is what they mean. water vapor is created by evaporation.

 

[petep1980]

Evaporating is what they mean. water vapor is created by evaporation.

Other than producing a higher gravity wort, what is the purpose of evaporating water?

 

[Satisfaction]

Other than producing a higher gravity wort, what is the purpose of evaporating water?

To make clouds that in turn produces rain that grows grains and hops? Just need a whole lot of homebrewers making beer at the same time to change the local climate..



But it is a good question, would be interesting to run a GC/mass spec on the wort pre and post boil to see what VOC's are present. I am sure there are all kinds of chemical changes going on that take place at nearly the same temperature water becomes steam.

 

[petep1980]

I am sure there are all kinds of chemical changes going on that take place at nearly the same temperature water becomes steam.

I bet it's tradition from back in the day before they had temps. They knew boiling killed stuff, so they just went ahead and boiled rather than guessing when they were above 165 or so.

We don't boil our meats, but we do boil spaghetti.

It's my nature to do things the easiest way I can think of. If the easiest way I learn is not acceptable then I want to know why. Then when I get an answer like "evaporate water vapor" I am displeased with the answer.

I have enough of an education to begin tackling some of these issues, and I need some new brewing challenges since I am obviously never going pro. I think it's time to start experimenting.