[crosswind]

I'm doing a presentation on the effects of boiling beer for my homebrew club so I decided to do a little experiment. I created a basic Bitter mash with an added 1.5oz of pellet hops to the mash. I recirculated for 60 minutes through my RIMS at 152F. I then ran half of the mash through my chiller into a fermenter and the other half I boiled for an hour. I didn't add anything in the kettle. Since the boiled half was in a non-ported kettle, I chilled it with an ice bath before racking to its fermenter. I let both fermenters equalize their temp by setting them in my cellar overnight before pitching in the morning.

That was about 2 weeks ago. Last night I kegged both and took a sample of each. They both started at 1.034 and finished at 1.004. One is clear enough to read through and the other is about as cloudy as a hef.

I would have guessed the unboiled wort would be the cloudy one, but it is actually the clear one. I can't explain why that would be. Finishing gravity is the same and the cloudy one doesn't taste infected. Does anyone have any idea what would have caused this?

[morticaixavier]

could it be that because the hot break protein never coagulated it's still in solution and there for not scattering light? just a guess.

[Jimmy K]

Herein lies the problem with many homebrew experiments. Without repetition it's hard to tell if differences are caused by the factor you're testing or something else that the person didn't think about or monitor.
 
My question wouldn't be - Why is the unboiled one clear? I'd be wondering - Why is the boiled one cloudy? Something seems to have gone sideways here.

[crosswind]

Right. My hypothesis was that the boiled one would be clear and the not-boiled would be cloudy. I'm confident I didn't mix the two up, but that would be the simplest explanation here!

I might try running a bit of the mash off my next batch into a small fermenter and see if it gets cloudy or clear. Until then, I don't know how to explain this to the club.

[hopfenundmalz]

You said you did not add anything to the kettle. Kettle finings like Irish moss are to help give a clear beer by pulling the hot break out. I think you illustrated why kettle finings are used.

[crosswind]

I have actually performed a past experiment on kettle finings that made its way into an issue of BYO. I normally throw 2 whirfloc tabs into each batch. Nothing here though. This was 002 yeast which drops clear pretty quickly.

Early on in their fermentation, they looked identical. The boiled is on the left, non-boiled on the right.


I'll admit that the left fermenter looks like it's begging for an infection, but I can assure you that's just on the outside and that it's been a long time since I've had an accidentally infected beer 

[Joe T]

I can think of a few variables in your experiment.
You chilled the mash wort through your chiller but the boiled wort got an ice bath. Maybe not a good cold break?
The boiled wort would have a lower pH. Not sure if that matters.
Shouldn't the boiled wort have a higher OG?
One keg/line/faucet/fermenter was dirty?
Would boiling precipitate out some of the calcium yeast need to floc?

[Joe T]

Enzymes still active in unboiled wort?
Do you have kids? Maybe someone poured in some milk?

[crosswind]

Hey Joe. Thanks for the suggestions. I can address a few of them...

I did think it may have something to do with the chilling method. Normally I cycle through the chiller a few times and the resulting wort is quite clear. I only did it once here (which didn't quite get me down to pitching temp) but maybe it's highlighting a benefit of using a good chiller.

I did not check pH on either.

The boiled wort was a higher gravity, but I did some math and topped it up with water until it hit the OG of the non-boiled beer. They both started at 1.034. Both finished at 1.004 too. That's 88% ADF which is high for 002, but I added sugar so that's not too surprising.

I do have a two-year-old daughter and those are just foil caps covering the fermentors. She may have tossed something in there!

I should add that the non-boiled beer dropped clear much faster than I normally get with 002, but then again I've never skipped the boil or had such a low OG with this strain. Now that both beers are kegged and in the fridge, maybe their clarity will change. I'll keep this thread updated when I find out. 

[Joe T]

I have a 5 year old daughter. I use carboys and she loves to watch the yeast doing their thing. I'm sure she would never mess with them! 
Nice experiment though. Really gets ya thinking! Thanks for sharing!  Keep'em coming!