My OG's are ALWAYS ALWAYS LOW!

[Laminarman]

I have done BIAB, kits, kits with specialty grains, my own recipes on Beersmith, all grain in 1 gallon "test batches"...etc. My beer tastes really pretty decent. But I am always low on gravity for some reason. With all grain I can attribute that to some efficiency issues with Beersmith and as I refine the recipes I get closer. But recently I have done 4 kits, all 5 gallon, from a well known on line retailer. All are clones. I am, as of today, 4 out of 4 with an OG lower than specified. I follow their directions EXACTLY. I will top up to exactly the 5 gallon mark like they say. Today I did a Sip of Sunshine clone, OG was to be 74, I was 53. This is what continually happens. Am I maybe not boiling vigorously enough? I boil, it's just not an aggressive boil as the boil overs are a PITA. I am doing stove top by the way. I have measured both with a refractometer and hydrometer, either way, I'm low. I do correct for temperature too. I am perplexed.

 

[Qhrumphf]

First place I'd look is wort mixing. Anything topped off will require significant effort to fully mix, and if your sample is more top off water than wort, your reading will seem low. With an extract batch this is almost always the issue as you can't really get the gravity wrong unless either you added the wrong fermentables or the wrong volume.

I'd check the volume of your fermenter. Pre-made bucket markings are sometimes wrong.

Check the calibration of your hydrometer. It should read 1.000 in water (technically distilled but tap water will work fine) at reference temp (most hydrometers that's 60F or 68F, your hydrometer or its paperwork will say which).

 

[pricelessbrewing]

Need more information. As @Qhrumphf said, volumes matter. If you're adding water after the boil, you should take the gravity reading, temp measurement, and volume measurement before adding water. Then do some simple math, or use a blending/diluting calculator, and calculate the diluted OG. You should always take gravity samples at room temperature, I never recommend a "hydrometer temperature correction calculator".

Can you provide information for 1 recipe, 1 kit, and if you have any extracts, that too. Complete recipe, and any volumes, gravities, and temperatures you measured*, and complete description of the process.

*eyeballing, using bucket markings, or using pitchers doesn't count as an accurate measurement,

 

[Laminarman]

Need more information. As @Qhrumphf said, volumes matter. If you're adding water after the boil, you should take the gravity reading, temp measurement, and volume measurement before adding water. Then do some simple math, or use a blending/diluting calculator, and calculate the diluted OG. You should always take gravity samples at room temperature, I never recommend a "hydrometer temperature correction calculator".

Can you provide information for 1 recipe, 1 kit, and if you have any extracts, that too. Complete recipe, and any volumes, gravities, and temperatures you measured*, and complete description of the process.

*eyeballing, using bucket markings, or using pitchers doesn't count as an accurate measurement,

Well this is already very helpful. I take the gravity after topping off with water, but as you can imagine, shaking a 6 gallon carboy filled up to 5 gallons is not easy. So I roll it around a bit and do the best I can. I guess I just assumed that a few good shakes was good enough. The 5 gallon mark on the carboy was made by me after measuring it out so I know it's accurate. I chill with a copper chiller to about 68-70 degrees before adding yeast and top up water. Water is the same source of bottled I always use at the room temp I'm brewing in, usually 68 degrees. Next batch maybe I'll take final boil gravity and volume I'm left with then use the online calculator for 5 gallons to see how close I am.

 

[Qhrumphf]

You don't need a calculator, the math is actually very easy. However, it requires you to *accurately* know your post-boil volume, as any error there will throw the math off.

Volume 1 * Gravity 1 (expressed short form) = Volume 2 * Gravity 2.

So 3 gallons of 1.065, topped up to 5 gallons, means 3*65=5*gravity, for a gravity of 39, or 1.039. Math works the same way for any volume or gravity form (Plato or SG, gallons or barrels), as long as you keep units consistent (Plato/Brix/Balling work as is, SG needs to be adjusted from 1.0XX to just the XX part)

 

[ElJefeBrews]

When I first started, the kits I used gave a horrible sparge technique and I didn't know better at the time and my OG was always low. Once I fixed that I never had a problem. What's your sparge technique?

 

[ike8228]

What I found with kits is that only do 1/2-2/3 of the water in the wort and top off at the end, but they say to top off until you reach the target OG that they recommend. I have ended up with 4-1/2 or 4-3/4 gallons in a '5 gallon' kit. You lose some of the liquid extracts in the canisters etc, that mess with this. Next time you do something, have a target OG and top until the hydrometer reads that.

 

[RM-MN]

Well this is already very helpful. I take the gravity after topping off with water, but as you can imagine, shaking a 6 gallon carboy filled up to 5 gallons is not easy. So I roll it around a bit and do the best I can. I guess I just assumed that a few good shakes was good enough. The 5 gallon mark on the carboy was made by me after measuring it out so I know it's accurate. I chill with a copper chiller to about 68-70 degrees before adding yeast and top up water. Water is the same source of bottled I always use at the room temp I'm brewing in, usually 68 degrees. Next batch maybe I'll take final boil gravity and volume I'm left with then use the online calculator for 5 gallons to see how close I am.

Mixing the concentrated wort with top off water is much more difficult than people realize. If you want to visualize it, take a clear drinking glass and fill it half way with water. Pour in a tablespoon or so of a dark honey and then roll it around like you would your carboy and see how poorly it mixes.

Anytime you do a kit that contains LME or DME that calls for top off water just go by what the kit might predict for OG. It will be more accurate than most hydrometer samples.

If you go to all grain brewing the wort won't be so concentrated so your first runnings and the sparge will mix easier but even then it is possible to have some stratification. However, during the boil the wort gets thoroughly mixed so the OG you read will be the correct one since you won't be adding top off water.

 

[RM-MN]

What I found with kits is that only do 1/2-2/3 of the water in the wort and top off at the end, but they say to top off until you reach the target OG that they recommend. I have ended up with 4-1/2 or 4-3/4 gallons in a '5 gallon' kit. You lose some of the liquid extracts in the canisters etc, that mess with this. Next time you do something, have a target OG and top until the hydrometer reads that.

If your kit instruction say that, throw the instructions away and quit buying those kits. It is so difficult to get proper mixing of concentrated wort and top off water that you are nearly assured of getting the wrong volume. You should have a volume of 5.25 to 5.5 gallons into the fermenter.

I use some of the heated water to rinse out the containers. There isn't much left when I am done.

 

[Laminarman]

For grain I do BIAB so no sparge there, and with my small batch 1 gallon test recipes I do a simple sparge with a colander, same technique every time (i get closest to my gravities oddly with this rather rudimentary technique). The extract/grain steeping kits and recipes throw me off and I do think that it's the top off water. I appreciate the honey and water analogy, I but I'm hardly mixed together at all : (

 

[Qhrumphf]

For grain I do BIAB so no sparge there, and with my small batch 1 gallon test recipes I do a simple sparge with a colander, same technique every time (i get closest to my gravities oddly with this rather rudimentary technique). The extract/grain steeping kits and recipes throw me off and I do think that it's the top off water. I appreciate the honey and water analogy, I but I'm hardly mixed together at all : (

Assuming your 1 gal batches are full boil, and closest to your gravity, then it certainly does indicate that all grain is an efficiency thing (not uncommon and a different discussion), but your big swings on larger batches are indeed top-off mixing related.

When I used to partial boil and top off (all grain included), i would measure post-boil and then calculate top-off. You can do the same. Far more reliable.

 

[Qhrumphf]

If your kit instruction say that, throw the instructions away and quit buying those kits. It is so difficult to get proper mixing of concentrated wort and top off water that you are nearly assured of getting the wrong volume. You should have a volume of 5.25 to 5.5 gallons into the fermenter.

I use some of the heated water to rinse out the containers. There isn't much left when I am done.

Depends on the kit. Most are designed to be topped off to 5 gallons, not more. At least every kit I've ever seen. Topping up more decreases gravity.

 

[RM-MN]

Depends on the kit. Most are designed to be topped off to 5 gallons, not more. At least every kit I've ever seen. Topping up more decreases gravity.

It also gets you to 2 cases of beer when you leave the trub in the fermenter. 5 gallons doesn't quite do it.

 

[Qhrumphf]

It also gets you to 2 cases of beer when you leave the trub in the fermenter. 5 gallons doesn't quite do it.

Yes, I know that, and my recipes are designed as such, 5.5 gallons into fermenter for 5 gals finished product, 11.5 gals for 10 gals finished product, 12.25 bbls for 11 bbls finished product, 24.5 bbls for 22 bbls finished, etc.

But most kits are NOT designed that way. If you are using a kit, and it says top off to 5, if you top off to 5.5 you will undershoot your gravity. Period. If that's ok by you, then that's great. But that's not gonna help the OP's problem.

 

[stuknkrvl]

How confident are you in your brew house efficiency?

I realize that shouldn't matter an awful lot where kits are concerned, but it took me a long time and a lot of trial and error before I finally figured out the efficiency of my most frequently used equipment.

I like BeerSmith and I use it often, but I've found over time that my recipes consistently come in under gravity when I use the program, even accounting for proper efficiency. It's a little labor intensive, but I hit my numbers damn near on the nose when I do the math and work out my recipes on paper first. Highly recommend Ray Daniels' book Designing Great Beers for learning how to do all that. Again, that's just my experience with BeerSmith, and in the spirit of full disclosure I have to say I've never really learned how to use it to the full extent of its abilities.

Good luck!