Why use a sight glass on brew kettle?

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geepmaley

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Been extract/PM brewing for years and looking at converting to all grain, so need a bigger pot. Looking at a keggle and want to understand the benefit of having a sight glass and thermo option on it.

Thanks
 
You want to know what temperature you're at and you want to know how much liquid you have.
 
I like to know what temp it is at, how close to boil its at, and also the temp while chilling, I use an immersion chiller so I transfer fromthe keggle directly to the carboy after chilling.

The sight glass is helpful so I know the preboil level, as well as post boil, nothing like missing your gravity numbers because you over or under shot your fermentation volume.
 
I have a sight gauge on my Polarware that I got recently. On the previous 150 batches or so, I used a wooden spoon with marks on it.

So I used it a couple weeks ago for the first time, and it's completely useless while it's boiling. Wort just cycles through it and bubbles and I can't see how it's doing during the boil. When the heat is off, I can tell how much is in there. I'm not sure what the point is, and I don't think it's necessary at all.

If I'm heating up sparge or mash water, I measure the amount going into the kettle with a gallon pitcher with markings on it so I know exactly how much is in there. No point in sight gauge for that purpose. I use it when draining wort into the kettle from mt, but it's just as easy to use a marked spoon.

Really no advantage that I can see except that it makes the brew kettle look badass to your friends.
 
So I used it a couple weeks ago for the first time, and it's completely useless while it's boiling. Wort just cycles through it and bubbles and I can't see how it's doing during the boil. When the heat is off, I can tell how much is in there. I'm not sure what the point is, and I don't think it's necessary at all.

Your boil sounds too vigorous. You just need a rolling boil, which will not cause volume fluctuation in the sight glass.

I love my sight glass and thermometer. Would not go back.
 
So I used it a couple weeks ago for the first time, and it's completely useless while it's boiling. Wort just cycles through it and bubbles and I can't see how it's doing during the boil. When the heat is off, I can tell how much is in there.

Try using some sort of heat shield under your sight glass while boiling. The heat shield prevents the contents of the sight glass from boiling.
 
I don't have a sight glass on my boil kettle, but I want one!

I have my spoon marked for my volumes, so it's not really needed to know my volumes. But where I found it would be so much more valuable is during the sparge. I could see at a glance if my fly sparging (in and out) is the same, since I have a sight glass on my HLT. As it is, I'm peeking into the MLT and trying to estimate if it's the same. Also, I could see half way through the boil if my boil off was the same without playing with my measuring stick/spoon.

It's not necessary at all, as I've never had one. But I can see the usefulness of one.
 
I just use a dedicated tape measure. I went through and took measurements of my kettles at various volumes and made up a chart that hangs in the brewery. I just take a reading and see where my volume is.
 
My buddy added a sightglass to his pot. He and I both deemed it not worth it. It's one more thing to clean. He uses his old pot now. On top of that, we know our boil off rates anyway. I'm rarely off by more than a 1/4 gallon so it's not really needed.
 
I just use a dedicated tape measure. I went through and took measurements of my kettles at various volumes and made up a chart that hangs in the brewery. I just take a reading and see where my volume is.

Good idea... Right now I use my wine thief which I've marked with a Sharpie, but I'm not sure it's as accurate as it should be. I need to do it again, and if I'm going to measure, that seems like a better option...
 
1) It looks badass and all sciency and stuff.
2) It's helpful to measure your current volume (provided you have a heat shield under it to stop it from bubbling)
3) A sight glass / thermometer combo is pretty nifty. Only one extra hole to drill in your keggle.
 
Try using some sort of heat shield under your sight glass while boiling. The heat shield prevents the contents of the sight glass from boiling.

+NEXTNUMBER

And...



I had the same wort-boiling-in-sight-glass issue and, though I didn't build anything as slick as Bobby M, I did put a temporary metal piece of something or other under the sight glass fitting for my last brew and no more bubbling sight glass volcano...

EDIT: Oh, and though a thermometer may not be necessary if you are mostly depending on a handheld instant-read one for your temps (like me), a sight glass is nice for the same reasons already stated here. Knowing your volumes goes a long way to getting your process down and repeatability.
 
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i have a stainless steel "stick" that i use that is marked off by 1/2 gallon.

imho, a sight glass is just something else that can mess up and ruin your brew day.
 
i have a stainless steel "stick" that i use that is marked off by 1/2 gallon.

Definitely nothing wrong with this technique. Whatever method of accurately measuring your volumes works for you is perfect for your purposes.

imho, a sight glass is just something else that can mess up and ruin your brew day.

If it's used properly (and take it from someone who was NOT using it properly for quite some time) it can do nothing but help your brew day. One more thing to clean maybe, but it's not an issue if you at least rinse your kettle shortly after emptying it. Quite a pain to clean them without the right brush once you've let crap dry in them. Learned my lesson there.
 
The sight glass is helpful so I know the preboil level, as well as post boil, nothing like missing your gravity numbers because you over or under shot your fermentation volume.

Or you could just make sure you boil off slightly too much and add water back. Too many variables to get it exactly right every time anyway.
 
Your boil sounds too vigorous. You just need a rolling boil, which will not cause volume fluctuation in the sight glass.

I love my sight glass and thermometer. Would not go back.


My sight gauge actually starts to boil BEFORE the rest of my wort. Even though I make the gauge the furthest point on my kettle from the center of the flame, it still starts boiling first. I don't even have a huge flame going on my burner.

I'll look into a heat-shield of some sort, also. That boiling gauge bugs the hell out of me.
 
Or you could just make sure you boil off slightly too much and add water back. Too many variables to get it exactly right every time anyway.

I have my process down pretty good so I hit my numbers almost every brew. Volume wise I'm dead on because I can monitor that, it's one less thing that could effect the final product, besides I brew 10 gallon batches so splitting it into 2 carboys evenly then topping them both up with water is more trouble than its worth.
 
Like Yooper said I use the sight glass to gauge the runoff speed from the mash tun when fly sparging. I also use one on my mash tun for the same reason. I find them extremely useful in setting a sparge rate evenly.

Even if the wort is boiling in the sight glass you can just lower the heat for a second and get a reading. Everyone's equipment and processes are different and will determine weather it makes sense for you. For me I have calibrated sight glasses on all my vessels and they make life much easier.
 
I never used a sight glass when I was doing 6 gallon batches in my straight sided pot. I just used a metal yardstick for height and did the math.pi*R²*H /231. Trouble was I couldn't measure during the boil, which was no problem. When I went to 11 gallons in a keggle I went to a sight glass. I didn't want to deal with the curved bottom and hop spider, and I already had a hole in my keg for a thermometer. I am glad to have the sight tube. It just makes things easier when filling kettles. I batch sparge in two equal batches and if I need a total of 8 gallons I pump it down to the 4 gallon mark. I don't have a boil issue in the tube. I can see as the hot water rises and cools and sinks to the bottom but it does not roll like inside the kettle. What I liked is I only set it up once and I can instantly see my levels. As far as keeping it clean, I just rinse it out when I'm done brewing and run a brush down it about every other brew day.
 
I thought about a sight glass, but in the end took the advice in this thread and got a stainless steel ruler from the hardware store. its 2 foot long. I measure in metric, and luckily my boil pot comes out to almost 1.5cm per Litre. So the maths is dead easy.

I used a tape measure for a while but it started to rust. the steel ruler is also better because its rigid and you can just leave it the boiler which I also use as a HLT and thus can watch the ruler whilst draining out strike water without having to hold a tape measure.
 
I got a pot that had a sight glass on it when I was upgrading. I didn't really care at the time, I wanted the pot for other reasons.

Now I can't imagine not having a sight glass. I couldn't go back!
 
I think that if I were to "upgrade" to a larger volume setup than five gallons, I may want one. But for now, knowing how far to measure down from the rim of my kettle is working just fine. Though I've never used one, I don't think a sight glass would be much, (if any) more accurate than my methods.
 
i have a stainless steel "stick" that i use that is marked off by 1/2 gallon.

imho, a sight glass is just something else that can mess up and ruin your brew day.

This is how I see it. I have a stainless steel dip tube with markings so I can work out preboil. Post boil is whatever makes it into the cube. I know my system well enough to know what to expect.

Sight guage will look cool but you probably should break it apart and clean it after each brew. Dial thermometer to my mind is just a waste of cash. If you can't tell how close it is to the boil by looking at the good foamy stuff forming on the top then you need new trousers. I guess it could help prevent boilovers but not overfilling the kettle does that fine for me.
 
advise from this thread would lead me to believe I would want a sight glass, not a ss ruler. when a vigorous boil is achieved and you have steam out the wazoo coming off your pot, the last thing I want to do is get my hands into it and stick my head in there to try and read the thing.

Sight Glass > SS Ruler > nothing at all.

now if your sight glass is boiling in the tube you need a heat shield. plain and simple end of story.

-=Jason=-
 
manticle said:
Sight guage will look cool but you probably should break it apart and clean it after each brew. Dial thermometer to my mind is just a waste of cash. If you can't tell how close it is to the boil by looking at the good foamy stuff forming on the top then you need new trousers. I guess it could help prevent boilovers but not overfilling the kettle does that fine for me.

I personally use my dial thermometer for strike and sparge temps as well as to watch my temp while chilling so I know when to pitch yeast. I can see the dial from across the room and don't need to be hunkered over the BK to monitor temps. I love it.
 
Are you using your brew kettle for your HLT?

I have a dial thermometer on mine but it's a separate vessel to the kettle. I also no-chill - makes sense to have one if you are chilling I guess. I forgot that bit.
 
Why do people keep commenting on the need to clean the sightglass? Just run clean water down it and you're done. You're going to boil the wort for an hour, so nothing will survive in the sightglass anyway.

Personally, I think Bobby M's sightglass was one of the best brewing purchases I've ever made. It had never failed me. I do occasionally get the sightglass to boil, but I just keep a spray bottle nearby and hit the bottom with cool water and it stops it from boiling.
 
Why does people keep commenting on the need to clean the sightglass? Just run clean water down it and you're done. You're going to boil the wort for an hour, so nothing will survive in the sightglass anyway.

Personally, I think Bobby M's sightglass was one of the best brewing purchases I've ever made. It had never failed me. I do occasionally get the sightglass to boil, but I just keep a spray bottle nearby and hit the bottom with cool water and it stops it from boiling.

in the event your sight glass is spewing hot wort and hops it needs to be cleaned.

just ask me how I know

-=Jason=-
 
manticle said:
Are you using your brew kettle for your HLT?

I have a dial thermometer on mine but it's a separate vessel to the kettle. I also no-chill - makes sense to have one if you are chilling I guess. I forgot that bit.

I have a 5 gallon cooler for my HLT. I heat up my sparge water to 180ish while mashing and throw in the HLT. Then I start heating my mashout water.
 
I have a Blichman sight glass brush I use when I clean the kettle and takes less than 5 seconds to clean. No big deal. I marked every half gallon on the sight glass and I can hit volumes with little effort. Im pretty sure once you have a sight glass it would be hard not to have one.
 
O.k., after being frustrated and thinking this thing sucks because it just boils all the time, I came up with an incredibly elaborate heat shield.

I used a rare and expensive material known as "Tin Foil".

Material Costs: 1 cent
Time of Construction: 40seconds

It worked brilliantly. It never boiled and stayed stable - no matter how much I turned up the heat. :ban:

SightGlassShield.jpg
 
O.k., after being frustrated and thinking this thing sucks because it just boils all the time, I came up with an incredibly elaborate heat shield.

I used a rare and expensive material known as "Tin Foil".

Material Costs: 1 cent
Time of Construction: 40seconds

It worked brilliantly. It never boiled and stayed stable - no matter how much I turned up the heat. :ban:

SightGlassShield.jpg

per Bobby_M's instrucional video about building a heat shield for his sight tubes I just bought the .45 cent piece of flashing and stuck it under my keggle and guess what = no more boiling in sight tube.

-=Jason=-
 
Why do people keep commenting on the need to clean the sightglass? Just run clean water down it and you're done. You're going to boil the wort for an hour, so nothing will survive in the sightglass anyway.

Personally, I think Bobby M's sightglass was one of the best brewing purchases I've ever made. It had never failed me. I do occasionally get the sightglass to boil, but I just keep a spray bottle nearby and hit the bottom with cool water and it stops it from boiling.

Everybody's experience is different. If it works for you then great - personally, I'd freak out a bit if I didn't clean/sanitise it because I highly doubt the wort in the sight glass is going to stay at pasteurising temps for very long.

I've thrown lovingly made AG wort/beer away after infection sinking its bastard claws into it so I'll do anything to avoid doing that again (yes I cried).

Anyway what works for you, works for you. I have a stainless dip tube from the inside of the keggle which I use for the purpose. Doesn't look as sexy obviously.
 
Like I said - your equipment, your experience.

I'd suggest that if it's not cleaned properly then whatever temp it gets to during the boil won't matter but I don't use one and you do with no problems.

If your experience suggests that they just need a good water clean then your experience is what I would use or recommend anyone else use over my opinion/perspective.

I'm probably being paranoid but that paranoia is based on my experience (of infections, not sight glass on kettle specifically) and that experience has led me to avoid fitting my kettle with a sight tube. I'm certainly not Captain Right and I have been known to change my opinion from time to time as it's not made of concrete.

I wish the term 'LOL' could be left to fester somewhere horrible.
 
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