What's Been The Most Inaccurate Equipment You Have Bought?

[PistolPatch]

I've long been fascinated by the inaccuracy of the measuring equipment we commonly purchase for brewing and think that it is a subject that should be talked about more often.

Posts on brewing forums will lead us to believe that a thermometer is accurate at all temperatures if calibrated in freezing and/or boiling water and that a hydrometer is accurate at OGs and FGs if checked in distilled water at 15 or 20 degrees.

Calibrating hydrometers and thermometers in the above manner is often the cause of mysterious (disappointing or miraculous) efficiencies and even failed mashes. West Coast Brewers here in WA actually had a thermometer calibration day at mash temperatures a few weeks back with some surprising results from what I heard.

Here are three examples of inaccurate equipment from my own experience...

1. Thermometers - Have bought a zillion of these. At a mash temperature of 66 degrees, from memory, the worst one I have tried was 5 degrees out from my most trusted thermometer. Many were over 2 degrees out.
2. Hydrometers - I had 4 hydrometers at one stage and whilst bored, tested them all in distilled water at room temp. All measured within 1 point of zero. I then tried all four in the same sample of a fully-fermented beer. Two read the same and the remaining two were three points above and three points below (spun and checked twice.) I then tested the same four hydrometers at OG levels of the beer I was brewing that day and the same sort of bewildering discrepancy occurred!
3. Supermarket 4lt Jug - I bought a supermarket 4lt jug with 0.5 lt graduations on the side. It held 3lts compared to the 4lts my 3 and 5 lt graduated brewing jugs both held!!!

If anyone wants proof of the above, I still have the "4lt" jug and at least one of the hydrometers! (I also think I have at least two dodgy mash thermometers that have long been banished to the far corner of the most obscure brewing drawer I have available.)

Has anyone else tested their equipment accurately and been a little shocked?

 

[A3k]

Yeah, i've gotta say i've had troubles with thermometers.

I have an all glass thermometer which i thought would be accurate, and a metal backed thermometer which i didn't trust (as i had one that slipped on the backing).

After using the glass one for ages, i checked it and the metal backed one with two electronic thermomters. They were all about the same except the glass thermometer which was 2-3 degrees out at 10C (testing my lager brewing temps).

Pretty annoying actually considering i bought is as i thought it'd be more accurate.

 

[peas_and_corn]

My taps. They would tell me that my keg is empty when i knew there was another litre left

 

[Tony]

Horrid plastic non digital kitchen scales i used to weigh grain..... and hops when i started brewing.

+/- 20% easy

it took about 50g or hops before they would register anything was there.

Welcome back PP

 

[A3k]

Horrid plastic non digital kitchen scales i used to weigh grain..... and hops when i started brewing.

+/- 20% easy

it took about 50g or hops before they would register anything was there.

Welcome back PP

Dang,
I don't like my kitchen scales and they move every 2g. Makes me feel better about them.

 

[Adamt]

All you want out of your brewing equipment (thermometer, hydrometer and the like) is for it to give you precise data, being somewhat accurate is good enough. If your instruments are precise you can reproduce brews with greater confidence. A precise hydrometer will give close readings for a finished beer, an accurate one will not necessarily do so.

You also must use your measuring equipment properly... what good is a perfectly calibrated thermometer if your mash isnt well mixed and isothermal? What good is an exactly 4L jug if you're measuring hot water with a lower density?

Another question to ponder: How many IBUs in a beer that Tinseth estimates at 25, Rager estimates at 31 and Garetz estimates 19? Answer: It doesn't really matter at a homebrew level, as long as you use the same method you get your own idea of how bitter "30 IBUs" are from your brewery.

 

[PistolPatch]

Just before I go to bed and in reverse order...

Adamt - Howdy old mate. Now what are you doing mentioning all that advanced stuff? I was gently trying to lead into all that and you go and mention it up front!!! I had some great stuff to say on what you wrote but way later!!! Good on ya though

A3k - Those thermometers have always been my best friends. The other day though, kook mentioned the same problem about them slipping. I suppose the only way to get around this is to make some calibration marks on them as soon as you buy them. And to think I really trusted these ones!

Tony - :beer: Going to come and visit you soon. Your wife said she is not getting enough. I think she meant beer

peas and corn - LOL! Too right!!!

Edit...

Cocko - Your post went up just before this one. Your constancy remark is spot on. Donya and thanks too :icon_cheers:

 

[Sammus]

My refractometer. I don't think it ever read the same number twice. Except 0 with water.

 

[newguy]

Horrid plastic non digital kitchen scales i used to weigh grain..... and hops when i started brewing.

+/- 20% easy

it took about 50g or hops before they would register anything was there.

+1.

It's cheaper in the long run to buy a good digital scale with resolution down to 1g for hops and >1kg max for grain. I haven't had issues with thermometers or hydrometers, other than the fact that they break far too easily.

 

[t2000kw]

When I buy a thermometer for cooking or other purposes, I look at many of them (or all the store has on display) and see what the average reading is. If there are outliers, I ignore them when coming up with an average. I find that most will read the same and take one of those.

I've never checked my hydrometer against distilled water and just assumed that it was accurate. I don't like those hydrometers with a thermometer built in since I can't check them out before buying them (I bought mine through the mail) and the one I had (before it broke) was off a degree or two. I don't always use one now unless I'm trying to duplicate a style. I don't need to know how soon I can bottle a brew, either, so I can wait a couple of weeks for fermentation (ales) to complete before bottling.

As for kitchen scales, I agree that they are difficult to get them to be repeatable, let alone accurate. But if you jiggle them a bit before taking any readings, I found that they get very close to repeatable results.

I did switch to digital scales. I have three. One for measuring hops, one that has a larger range up to about 4 or 5 kg, and another good to about 14 kg. The smaller ones will generally be more accurate in measuring small amounts. The bigger ones wouldn't be the best for measuring out small quantities of hops, but they are great for the quantities of grain you might weigh for an AG brew.

I might mention here that for weighing out kilograms of grain, a baby scale is more than adequate. I removed the baby holder part and just set my container on top of the scale, then zeroed out the scale with the container on it and added my grain(s) to the container. If it's off by several grams it isn't a problem since that isn't an appreciable percentage of the grain weight being measured. I bought mine used at a yard sale for a small amount of money, I think it was $2 USD. Even though I have a digital scale sometimes it's more convenient to use the baby scale which is in the garage where my grain is.

I have wanted a refractometer (I'm about to be laid off for a couple of weeks and my work schedule has been variable at best lately), but I've put off buying one for a while. Now that someone said that theirs is not repeatable, I wonder if one is a good investment at all?

Donald

 

[Tony]

Tony - :beer: Going to come and visit you soon. Your wife said she is not getting enough. I think she meant beer

She gets plenty mate

She can pull one when ever she likes around here :icon_cheers:

 

[A3k]

A3k - Those thermometers have always been my best friends. The other day though, kook mentioned the same problem about them slipping. I suppose the only way to get around this is to make some calibration marks on them as soon as you buy them. And to think I really trusted these ones!

To be honest, the slippage was my fault. It was my second AG a few years ago and i was checking the temperature of the kettle, trying to see how far off the boil it was.
Then Butterfingers Al (me) dropped the thermometer into the kettle. I thought it was going to be a disaster when couldn't fish the damn thing out with a coat hanger. I didn't want to leave it in to break and ruin the batch, so i tipped the whole lot into a fermenter, fished it out, then tipped back into kettle again.
I was pretty worried about what i'd read from HSA, as both pours caused lots of splashing, but i didn't notice any.

It took me a couple of batches of overly sweet beers to realise that my thermometer was off by about about 5 degrees. So rather than mashing in at 67, it was more like 72.

Anyway, those thermometers have glue on the back of them holding them in place, it's not just the two metal bits around the front... The glue must go soft when that hot. It had slipped far enough to expose the glue, so i could see the problem once i thought to look.

Al

 

[braufrau]

I calibrated my jug on the kitchen scales ... but are my scales accurate?? I think they are because 50g of hops from beerbelly weighs 50g.

Anyway, I don't use it anymore, now I do AG, I measure with a big blue bucket, which is close enough. If big blue bucket says 15l in and I get 15l out of the sparge then that's 15l, you know .. its like they stopped measuring the speed of light and made everything else relative to it. :unsure:

But *thermometers* .. don't get me started. But I just happened to notice a mysterious charge from beerbelly on my credit card so I think there's a new one coming soon .. on the 10th. Would have got it this weekend but I set HWBO right, and told him mother's day is *next* weekend. :lol:

 

[Fents]

PP's BACK!

If you only have one of each hydro, scales and thermo they'll never be inaccurate

 

[Smashin]

My taps. They would tell me that my keg is empty when i knew there was another litre left

I know the feeling, all 4 of my taps suffer the same error lies, at least they are all consistent :icon_chickcheers:

 

[np1962]

SWMBO!!

Always telling me one thing when she is actually doing something completely different. h34r:

Nige.

 

[Cocko]

Cocko - Your post went up just before this one. Your constancy remark is spot on. Donya and thanks too :icon_cheers:

Yeah, I had had a few, surprise surprise!, re-read it and it made no sense so deleted it! But thinking back it did makes sense!

It was basically a long winded version of what Fents said; If you use one piece of kit as a constant you can adjust around it...

I think...

 

[captaincleanoff]

the first pot I got was a cheap stainless steel chinese job - supposed to be 50L, but only held about 45

 

[brettprevans]

my wife h34r:

a hydrometer.,

edit: oops nigeP62 beat me too it

 

[muckey]

have to agree with p&c - the most innaccurate thing around here is also a beer tap - reminds me should be weighing grain for a brew ( shutup butters)

but seriously, getting back to OP, not only is it important to understand your equipment and it's inaccuracies - it will be if it's not regularly calibrated but for me its far more important to use a consistent method when using hydrometers, thermometers etc or basically any measuring device otherwise the errors that can be introduced can be far greater than the inaccuracy of the equipment