Missed my OG

[poizonpyro]

I've done close to 6 extract/mini mash batches and 6 all grain batches, and never had a problem hitting my OG.

I've now done 2 BIAB batches (1gal) and both times i have missed my OG by 0.20 - 0.30 The first batch my mash temp was a little on the low side (150), but this time it stayed between 153 and 156 so I'm a little confused as to why I missed it by so much.

I did have about a quarter gallon of wort left over after filling the carboy, so maybe that is the reason?

 

[C-Rider]

I've done close to 6 extract/mini mash batches and 6 all grain batches, and never had a problem hitting my OG.

I've now done 2 BIAB batches (1gal) and both times i have missed my OG by 0.20 - 0.30 The first batch my mash temp was a little on the low side (150), but this time it stayed between 153 and 156 so I'm a little confused as to why I missed it by so much.

I did have about a quarter gallon of wort left over after filling the carboy, so maybe that is the reason?

I'm guessing you mean you missed by 0.020-0.030
Crush is the first place to look. I always run it thru the mill twice at my LHBS.
Post at least one recipe and how you did everything.

 

[poizonpyro]

Type: All Grain
Batch Size: 1.00 gal
Boil Size: 2.32 gal
Boil Time: 60 min

3 lbs 10.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 90.6 %
6.0 oz Caramel/Crystal Malt - 40L (40.0 SRM) Grain 2 9.4 %
0.41 oz Columbus (Tomahawk) [15.20 %] - Boil 60.0 min Hop 3 70.7 IBUs
0.21 oz Columbus (Tomahawk) [15.20 %] - Boil 10.0 min Hop 4 13.1 IBUs
0.21 oz Simcoe [13.70 %] - Boil 10.0 min Hop 5 11.8 IBUs
0.21 oz Ahtanum [5.20 %] - Boil 5.0 min Hop 6 2.4 IBUs
0.21 oz Nugget [14.50 %] - Boil 0.0 min Hop 7 0.0 IBUs
1.0 pkg Safale American (DCL/Fermentis #US-05) [50.28 ml] Yeast 8 -
0.21 oz Ahtanum [6.00 %] - Dry Hop 7.0 Days Hop 9 0.0 IBUs
0.21 oz Nugget [13.00 %] - Dry Hop 7.0 Days Hop 10 0.0 IBUs

Est Original Gravity: 1.094 SG
Est Final Gravity: 1.025 SG
Estimated Alcohol by Vol: 9.2 %
Bitterness: 98.1 IBUs
Est Color: 9.4 SRM


The grain was only run through the mill once at the homebrew shop. I added the water to a 5 gallon pot, turned the stove on, stuck my thermometer in it. Once it reached 160 F, I added the grain to the bag (a paint straining bag from Lowes) and lowered it into the pot. The temperature dropped to 153F and stayed between 150 and 156 for the hour. I turned the heat up and brought the temp to 168 F for the 10 minute mash out. I drained the grain fairly well, while waiting for the wort to boil. Once it was boiling i followed the hop schedule, and starting cooling it right after the hour. got it down to about 80 F in 25 minutes. At that point i took a gravity reading of 1.065 when I was expecting it to be close to 1.094.

 

[dustinstriplin]

You have to stir the s*** out of it. When I first started doing biab I didn't stir well. I'd usually be off by about .01. Make sure to squeeze the bag really well also.
You should also expect lower efficiency on higher gravity beer.

 

[poizonpyro]

You have to stir the s*** out of it. When I first started doing biab I didn't stir well. I'd usually be off by about .01. Make sure to squeeze the bag really well also.
You should also expect lower efficiency on higher gravity beer.

I stirred it. Maybe not enough? Should I be stirring for the whole hour? or just periodically? I squeezed it as best I could...I'll try using a colander and a lid next time. Being off by .01 I could almost live with but that .03 sucks.

 

[RM-MN]

I put the bag into the hot water and stir the grains into it. I've found that a stiff wire whisk beats a spoon for breaking up dough balls and gets me a nice bunch of wet grains. If you put the grains into the bag first and then stirred, that's likely the problem. Somewhere below where your spoon reached there was a dough ball.

I only stir when I add the grains. The colander with a lid to press the grains down works very well.

Any left over wort contains fermentable sugars and without that in the fermenter, your gravity will be a little low. If necessary, boil a little longer so all the wort fits.

 

[brokebucket]

my first BIAB, I missed by .012 because I didnt want to hassle the guy at LHBS to run it twice....since then, I insist he runs it twice even though he tells me it shouldnt matter. I have been spot on since then. Of course, I am making smaller beers than you too. My biggest has been around 1.060.

 

[poizonpyro]

So, next time I'll have the guy at the LHBS run it twice, use the colander and lid, stir as I put in the grain (maybe put a little at a time to help avoid clumping?), and use less water and top it off in the fermenter if need be.

 

[jCOSbrew]

In a small 1 gallon batch if your volume is by a few ounces it could dilute your beer and effect your calculations significantly. An extra loss due to grain absorption could also have an effect.

To dial in your process calculate your mash efficiency by taking a refractormter reading (or cooling a sample for hydrometer) after the mash and before the boil. You have to be able to accurately measure the volume of wort collect and know the PPG for the grains you are using. Online calculators like brewersfriend will calculate this for you. Use brewhouse efficiency of 70% (or less) for your recipes until you get repeatable results.