# How do you know "how much is left in the keg"?

### Help Support Homebrew Talk:

#### jwill911

##### Supporting Member
HBT Supporter
OK up front I'm new to kegging but it didn't take me long to think "how much is in the keg"? I'm thinking weigh an empty keg, weigh the partial, do some math on weight of beer and determine how much is left in the keg.
How do you do it? Thanks for any better way,
John

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#### magno

##### Sound Level Technician
I don't have one of these, but they seem pretty slick... I usually just pour beers until I'm suprised by the keg blowing.

#### Hans O. Lowe

##### Well-Known Member
That's pretty darn cool. I didn't know such a thing existed.

#### bionicbelly

##### Supporting Member
HBT Supporter
"I usually just pour beers until I'm surprised by the keg blowing."

It's always a shock.

#### bracconiere

##### Jolly Alcoholic
HBT Supporter
How do you do it?

well, i do it a few ways....sound & science. if you knock a keg with your knuckles the sound is a dead give away for how much is in it....and science, i count every 12oz pour and write it down and can get a good idea by looking at my records.....

i saw someone that keeps their kegs on a digital scale in the fridge that stays on 24/7 though...would be more accurate then my methods....but i just try to make sure i have ANOTHER full keg as back up at all times....

genious

#### camonick

##### Mediocre brewer... Expert drinker
HBT Supporter
OK up front I'm new to kegging but it didn't take me long to think "how much is in the keg"? I'm thinking weigh an empty keg, weigh the partial, do some math on weight of beer and determine how much is left in the keg.
How do you do it? Thanks for any better way,
John
Keep in mind that unless you filled your keg from a brite tank or filtered it first, there will be a small amount of yeast/ sediment on the bottom that will get stirred up whenever you move it and can take some time to become a clear pour again (unless you leave it on the scale for the entire life of the keg).

#### RodeoDave

##### Member
I don't have one of these, but they seem pretty slick... I usually just pour beers until I'm suprised by the keg blowing.

This is a great example of what is great about home brewing today. Home brewers have always been resourceful and creative. With the internet (thanks Al) not only is this man able to take his ideas directly to his market but forums like this enable the members to help create awareness. His siphon is another elegant solution and dual purpose.

#### Rippchen

##### Member
Just build a scale with scale sensors and connected them to the raspberry pi in my keezer. Every one as a rasp in their keezer, right?

#### youngdh

##### Well-Known Member
I don't have one of these, but they seem pretty slick... I usually just pour beers until I'm suprised by the keg blowing.

I use these on my kegs. They work great, however, you can’t move or disturb the keg once the metal ball is in place or it will fall off. I have to remember to apply the catch magnet if I need to move or jostle the keg for any reason.

#### GrowleyMonster

##### Well-Known Member
I can tell by tipping the keg just a few degrees, not enough to unsettle the sediment in the bottom but enough to tell me that there is still significant mass of beer left. When it feels light to the tipping, I lift it one handed slightly with the handy handle. When it lifts effortlessly I know I am down to the last few glasses. My next keg is already in the fridge beside the tapped one, I just scoot it over into position and hook it up. Then I put the next backup keg in the backup position and after a few days I pull a glass with a faucet mounted right on the beer post, to clear the bottom and the beer out tube, and check the beer and the carbonation. Then it's ready to go when I need it. Sometimes I have to bleed the keg pressure a few times to get it absolutely ready to serve. Perhaps a spunding valve should be on my wish list. At any rate, long before I am surprised by an empty keg, my backup is in all respects ready to hook up and serve, so the empty keg is no great tragedy or inconvenience.

I don't use a level sensor because no matter what, I am still going to have that last glass of beer. I don't call the keg empty until the first sputter of gas comes out the faucet. It takes all of two minutes to change the keg.

#### DaveS

##### Active Member
Just build a scale with scale sensors and connected them to the raspberry pi in my keezer. Every one as a rasp in their keezer, right?

@Rippchen Do you have issues with the load cells reported weight drifting over time ?
I am considering this method as well but read people have issues with drift.
I have procured some flow meters which is another option.

#### scrap iron

##### Well-Known Member
I just weigh them after carefully removing from the kegerator. If they are in there awhile and cold the yeast pretty much stays at the bottom. An empty keg weighs about nine pounds and one gal water weighs 8.345lbs @ 39.2° F . So a full keg @ 5 gals is around 50 lbs, 41.72lbs plus 9 pounds for the keg.
I love math

#### jrgtr42

##### Well-Known Member
I just lift mine a couple inches. I have plenty of spares, so I know about how much an empty weighs, so I more or less ju\dge from there. I don't need to know EXACTLY how much is there, like I don't need to know there's exactly 2.5485370 gallons left, |I just there's "a bunch" still in there. When it gets light, I know I'm almost at the end.

#### youngdh

##### Well-Known Member
I can tell by tipping the keg just a few degrees, not enough to unsettle the sediment in the bottom but enough to tell me that there is still significant mass of beer left. When it feels light to the tipping, I lift it one handed slightly with the handy handle. When it lifts effortlessly I know I am down to the last few glasses. My next keg is already in the fridge beside the tapped one, I just scoot it over into position and hook it up. Then I put the next backup keg in the backup position and after a few days I pull a glass with a faucet mounted right on the beer post, to clear the bottom and the beer out tube, and check the beer and the carbonation. Then it's ready to go when I need it. Sometimes I have to bleed the keg pressure a few times to get it absolutely ready to serve. Perhaps a spunding valve should be on my wish list. At any rate, long before I am surprised by an empty keg, my backup is in all respects ready to hook up and serve, so the empty keg is no great tragedy or inconvenience.

I don't use a level sensor because no matter what, I am still going to have that last glass of beer. I don't call the keg empty until the first sputter of gas comes out the faucet. It takes all of two minutes to change the keg.
Assuming you have a keg to exchange ;-). I use the level indicator as it gets near the bottom as my indicator that I need to brew soon since my beer fridge can only hold the two kegs currently on tap.

#### GrowleyMonster

##### Well-Known Member
Assuming you have a keg to exchange ;-). I use the level indicator as it gets near the bottom as my indicator that I need to brew soon since my beer fridge can only hold the two kegs currently on tap.
Ah. Well, then. I have four good kegs and one sucky one, room in the fridge for two, but a faucet for only one. I drink a keg usually in 3 to 4 weeks. When one is empty, I brew. If I notice the on tap keg getting kinda light, I brew. If I am a week or two behind on brewing, I still got plenty of beer, plus now I keep a stash of bottled beer for emergencies.

#### day_trippr

##### "This Space For Rent"
I run Raspberry Pints "classic" for my tap list using SwissFlow SF800 flow meters. Very accurate, I can count on a keg kicking within a glass either side of empty...

Cheers!

#### agentbud

##### Well-Known Member
^ "either side of empty" ?
If it's on the negative side of empty, you're a glass behind, me thinks.

#### agentbud

##### Well-Known Member
ps - if you've got a clone recipe for juicy bits, I'd love to see/try/brew/drink it.

#### DuncB

##### Well-Known Member
@jwil911

@agentbud

If you don't have the subscription then the 30 day free trial should get you through this and the recipe

also

but this is the recipe from beer and brewing

I brewed the Weldwerks fitbits clone which was very good.

#### scrap iron

##### Well-Known Member
I just lift mine a couple inches. I have plenty of spares, so I know about how much an empty weighs, so I more or less ju\dge from there. I don't need to know EXACTLY how much is there, like I don't need to know there's exactly 2.5485370 gallons left, |I just there's "a bunch" still in there. When it gets light, I know I'm almost at the end.
Yeah, not everyone likes math, but many do.
cheers 3.1415926535 times!

#### Jonakr

##### Well-Known Member
I don't have one of these, but they seem pretty slick... I usually just pour beers until I'm suprised by the keg blowing.

I use these. They're great. I have one keg that the outside magnet falls a few pours before the keg kicks, but that's not much of a problem.

#### GoodTruble

##### Supporting Member
HBT Supporter
This thread reminded me to check my keg levels. Not good. Going to need to brew again sooner than I though. =c)

#### hout17

##### Crush it REAL Good
HBT Supporter
Yeah, not everyone likes math, but many do.
cheers 3.1415926535 times!

You made me hungry now I'm going to have to go and get a piece of blueberry PI.

#### DuncB

##### Well-Known Member
Raspberry PI will be more useful for this problem!

#### wepeeler

##### Supporting Member
HBT Supporter
If you figure a full keg is 48 12oz pours or 40 pints, you can be fairly accurate if you mark down when you grab a pour. I used to mark down every time I grabbed a pint, but it gets a bit hairy with 7 kegs going. And late night pours....

#### tracer bullet

##### Supporting Member
HBT Supporter
I too have a calibrated arm. I'm kidding of course, I'm not exact, but I have a pretty good idea of "plenty left" vs. "almost gone".

I dunno, it's really not that hard and not something that needs to be fixed. And believe me, as an engineer, I love fixing things.

#### jrgtr42

##### Well-Known Member
I run Raspberry Pints "classic" for my tap list using SwissFlow SF800 flow meters. Very accurate, I can count on a keg kicking within a glass either side of empty...

View attachment 757036

View attachment 757037

Cheers!
WIth something like this, how does the system know how much there was to start with? Do you enter, say, "5 gallons" into the program and it counts how much is poured? Sensors in the taps or something? or is there a scale or something attached?

#### DuncB

##### Well-Known Member
Interestingly on the webpage raspberrypints.com

It doesn't mention starting volume as a field, but it must be a requirement. I'd just like a digital taplist and then wing it on a piece of paper for how much I think was used ( drunk ) .

#### superiorsat

##### Well-Known Member
I use the force! If that doesn't work I just lift it if I really need to know how much is left for some reason. Like will it hold up and have enough for a party or should I replace it. It doesn't take to terribly long for the sediment to resettle. I will say it kind of makes you nervous pouring the last few pints as it is almost devastating when the keg blows. The wife's keg blew out last night one beer before she was ready to call it a night. I had been razzing her for the last couple days that her keg was like a circus clown car and every beer could be her last. Worse yet is when you have multiple blow outs in a night. Usually after a party this will happen, like blow 3 one night and 2 the next which just happened to me after New Years.

#### matt_m

##### Supporting Member
HBT Supporter
I'll usually get a rough gage by lifting them once in a while. But I know I'm nearing the end when the pours are amazingly clear.

#### Brewdog80

##### Supporting Member
HBT Supporter
does it really matter? I've two kegs in the fridge, one gets about a third to half empty before ai start sampling number 2. When I empty number 1, then number 3, which is ready to go in the fridge fully carbonated goes in. I start over. Brewing another well before the number 2 is empty. Always a spare..... what else would I need to know? Last glass is just the end of that batch and the start if the next.

#### Murph4231

HBT Supporter
Lmao I rarely check. I just replace it when it kicks or I simply get tired of it.

#### BigDave1303

##### Well-Known Member
I've made a few of these. magnetic float/ball bearing indicators, in true Blue Peter style. After putting the magnet in I hot glue the lid on. It's not exact but close enough. The metal bolt is to counter balance the weight of the magnet at the other end of the plastic tube.

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#### Brooothru

##### Well-Known Member
I use these on my kegs. They work great, however, you can’t move or disturb the keg once the metal ball is in place or it will fall off. I have to remember to apply the catch magnet if I need to move or jostle the keg for any reason.
"Santa" brought me several of those this year. I haven't had the chance to brew or put any in a keg yet, but it's good to know they work.

#### day_trippr

##### "This Space For Rent"
WIth something like this, how does the system know how much there was to start with? Do you enter, say, "5 gallons" into the program and it counts how much is poured? Sensors in the taps or something? or is there a scale or something attached?

As stated there are flow meters between kegs and faucets. Initial keg volume is calculated from weight and entered by the user, everything from there is automagic

Cheers!

#### Dr_Jeff

##### Supporting Member
HBT Supporter
but a faucet for only one.

I have a number of faucets and shanks that need a home.

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