Hydrometer Readings & Calibration

[lexuschris]

Hey all,

So now that I have 8 AG batches under my belt, and feel comfortable with my basic AG techniques, I am ready to start looking into my mash efficiency. I've not concentrated on that much, but my OG's are usually a few points below my targets (using a 72% brewhouse efficiency in BeerSmith). In some cases they are off by a dozen points.

Oddly, my FG readings are also consistently 5-6 points below BeerSmith's predictions. So, tonight I decided to check the calibration of my aged hydrometer. In room temp tap water 0.992. Ah-ha. Also, I noticed that the paper chart inside had the SG's for 60-F temp, which is not my usual measuring temp. So I put an icecube in the sample tube to lower the temp a dozen degrees or so.. 0.996. Then, I emptied the tub and but hot tap water in (bath water temp)... 0.990.

So, my hydrometer is definitely giving me low readings at my typical 70-F measuring temp. I don't see a way to calibrate it. I could certainly, just take some more readings with digital temps, and come up with an adjustment factor. And, I should probably take a temp reading of my beer when I take the OG readings, and adjust them for temp.

Any other ideas to help on taking readings? Would I be better off getting a refractometer? Would temp still be a factor?

Many thanks!
--LexusChris

[backyard brewer]

There is a calculator in ProMash and I would think in BeerSmith as well that, given the OG taken with a refractometer will compensate for the alcohol in a finished reading.

[brahn]

In my experience a refractometer is fine for quick measurements if you're just looking for a ballpark figure. It's nowhere near as accurate as a hydrometer though. Plus, the hydrometer requires you to pull a sample, which you get to drink!

Chris, you won't be able to calibrate the hydrometer, but I believe it will be off by the same number regardless of being in water or wort so you can simply add. I do agree with Robert about the efficiency. Don't worry about the number, just try to get something that works for you and stick with it. I don't know if you batch or fly sparge, but with batch sparging you'll see lower efficiency in bigger beers. I'm not sure if that happens with fly sparging as well or not but I would think so unless you're running off a huge volume of wort and boiling it down. I may get 79% at 1.048 and 68% at 1.100.

[lexuschris]

Thanks for the feedback!

I like the idea of not worrying about achieving some 'high mark' in efficiency. I'd rather just have good beer.

I just want to get to the point where I can better predict where my OG will end up, so that I can plan accordingly with extra grain additions. I tend to target 6-8% ABV beers, so when I mess up .. I still end up at 4-5% which is fine. As an example, here are my OG estimates @ 72% BE, vs. OG read via hyrometer @ pitching temp.

#1 Amer.Amber Ale est. 1.059 / read 1.060
#2 Amer.Pale Ale est 1.057 / read 1.052
#3 Old Ale est 1.095 / read 1.080
#4 Amer.Wheat Ale est 1.051 / read 1.047
#5 Amer.IPA est 1.077 / read 1.061
#6 Amer.Brown Ale est 1.070 / read 1.069
#7 Amer.Pale Ale est 1.053 / read 1.050
#8 Amer.IPA est 1.074 / read 1.058

These are the readings as taken, without temp corrections or adjustments. So, I guess I'm not too far off (except on #5 & #8 my two IPAs...).

I guess I'll just work on temp corrections + adjustment and see how I do on the next few. Beer tastes good enough!


Thanks all!
--LexusChris

[lexuschris]

BTW..

I am currently batch sparging. After mashing at step temp, I drain the tun (post vorlauf) to the boil kettle. Then I pour my single batch sparge volume @ 170-F into the tun. That stirs up the grain bed really well, and I put the lid on and wait 10-20 minutes. Then drain that (with more vorlauf) to the brew kettle. That is my boil volume.

I was wondering if I should split my batch sparge into 2 volumes with a 10 minute rest at each, in order to get more efficiency.... ?


--LexusChris

[jward]

I just want to get to the point where I can better predict where my OG will end up, so that I can plan accordingly with extra grain additions.

I was going to suggest consistently hitting ones OG is the holy grail and not chasing higher efficiency. Of course, if you have predictable efficiency you also have consistent OG too. +1 to Roberts comments about not chasing higher efficiency.

I am currently batch sparging. After mashing at step temp, I drain the tun (post vorlauf) to the boil kettle. Then I pour my single batch sparge volume @ 170-F into the tun. That stirs up the grain bed really well, and I put the lid on and wait 10-20 minutes. Then drain that (with more vorlauf) to the brew kettle. That is my boil volume.

I was wondering if I should split my batch sparge into 2 volumes with a 10 minute rest at each, in order to get more efficiency.... ?

I wouldn't add another batch/sparge. If you try it make sure the last batch isn't so low on gravity that you start getting tannin extraction.

I recommend that you add water to the mash just before vourlof/sparge. You will get more sugar out because of temperature increase and by virtue of more water. That means less sugar for the second sparge but still plenty of it to avoid problems. I think getting more out of the first means getting more out of the second too or higher total efficiency. I try to add enough water to the mash to get half the boil water, but I measure what's in the kettle to determine the actual amount needed for the second batch.

[lars]

BTW..

I am currently batch sparging. After mashing at step temp, I drain the tun (post vorlauf) to the boil kettle. Then I pour my single batch sparge volume @ 170-F into the tun. That stirs up the grain bed really well, and I put the lid on and wait 10-20 minutes. Then drain that (with more vorlauf) to the brew kettle. That is my boil volume.

I was wondering if I should split my batch sparge into 2 volumes with a 10 minute rest at each, in order to get more efficiency.... ?


--LexusChris

Hey Chris, There is one school of batch sparging that advocates splitting your sparges into two seperate rounds. You do not change the volume of water you are using, just split it into two batches. This is what I used to do before building my brew stand. I had great success doing this and I think my efficiency went up a touch. I used to consistently get 73% bachsparging.

As the others mentioned, it is better to be consistent and predictable than chase after super high efficiency. I'd much rather know how much sugar I'm going to extract from my grains than have to guess and miss my target.

[brahn]

I am currently batch sparging. After mashing at step temp, I drain the tun (post vorlauf) to the boil kettle. Then I pour my single batch sparge volume @ 170-F into the tun. That stirs up the grain bed really well, and I put the lid on and wait 10-20 minutes. Then drain that (with more vorlauf) to the brew kettle. That is my boil volume.

I also batch sparge, and I aim for two equal volume runoffs. 6.5G each in my case, for a total of 13G in the kettle. To do this, I typically have to add some water after the rest before the first runoff. It may take a few brews to get this calculation right, but once you do this is pretty simple. Then add the second batch of water (basically always 6.5G), stir, vorlauf and drain. There's no need to wait after you add the water before you runoff. Conversion has already happened and all you're trying to do is rinse the grain so there's really no need to wait.

[dhempy]

Plus 1 for what Brent and Lars said. I typically batch sparge with 2 batches ... no rest, just immediate vorlauf. I put a couple of drops in the refractometer every couple of minutes ... and usually between 5 and 15 minutes is all that is necessary for the reading to stabilize ... then it is off to the boil pot. Depending on the recipe I'll see a brix reading of up to 10 or 11 for the first batch, then 5 or 6 on the second but it does vary.

Dan

[lexuschris]

Following the advice here, I took a measurement in 60-F water, and used that calibrating adjustment (+.010 SG) for all my recent batches. That did put me right around the 70% efficincy I was expecting.

However, this weekend, I brewed an IPA, and when I took my OG reading, it came out impossibly low, even with the +.010. (was expecting 1.070, and got 1.055 adusted).

It felt like I must have done something wrong in my mash, to not get it converted properly. As I was cleaning out my spent grain from my tun, I mentally walked through my mash steps, my boil steps, etc. Everything went smooth as silk..

So, I decided to test my hydrometer in plain water again... 0.980 ... it moved another .010 .. so now my adjustment should be +0.020!!

I'm done with this old hydrometer, and will buy a new one. Do they all suffer from the slipping cardboard in the tube syndrome? Anyone recomend a particular hydrometer out there?
--LexusChris

[backyard brewer]

Someone here had a beautiful set of narrow range hydrometers. These things were just gorgeous and the scales were for very narrow bands; like .900-1.025; 1.020-1.045... I think there were 3-4 in the set that covered to 1.20.

Was that anybody that is still here? Where did you get them? I remeber being floored by how cheap they were. I want to say $60 for the set.

[jward]

Do they all suffer from the slipping cardboard in the tube syndrome? Anyone recomend a particular hydrometer out there?

I still have the first one I purchased. It has started to slip too. I can tap the paper back in place and even see where it's suppose to be based on a stain on the inside of the tube. I think you are suppose to break the cheap ones before they start to fail like this. I picked up a new one at AHP. It's a different model then the old one from B3 but I expect it's quite run of the mill for home brewing.

[oc eric]

There are, and I am not joking, about 20 different types/models of hydrometers. If you want something specific (no pun intended), let me know. I am placing an order today if you want it in a hurry.

[bwarbiany]

I do all of my pre-fermentation gravity readings using a refractometer. I just find it's easier to use the pipette to grab a tiny bit of wort, and I don't have to worry about temperature or sanitizing the hydrometer tube. Brent's comment about them not being anywhere near as accurate as the hydrometer is news to me...

I consider it one of the better equipment purchases I've made for AG brewing.

[BrewMasterBrad]

Get a refractometer from Eric, you won't ever go back to using a hydrometer on brew day.