Help me figure out what went wrong?

[DoubleAught]

I brewed my first AG batch today. I used the BIAB method with an 11 gallon SS pot. I brewed NB's Caribou Slobber kit, here's the grain bill.

9 lbs Rahr 2-row pale
.75 lbs Briess Caramel 60L
.5 bs Briess Caramel 80L
.25 lbs Fawcett Pale Chocolate
.125 lbs english black malt

1oz US Goldings @ 60
1oz Liberty @ 30
1oz Willlamette @15

using this BIAB Calculator | Beer Review Dude I filled the pot with 8 gallons of water, heated to 160, added grains and held it between 150-155 for 1hr, raised the heat to 170 and held for 10 mins. After the 10 mins I held bag over wort until water came to a drip.

I did my hour boil, cooled wort to 70 degrees and checked my gravity. It came in a 1.041, target OG was 1.052.

Not sure what I did to miss the gravity and was hoping someone could see if I could do something differently for next time.

Thanks for any advice!

 

[TipsyDragon]

the target OG of 1.052 assumes a particular efficiency in the brewer's mashing tun. Your efficiency is obviously lower. it happens. from the sound of it it sounds like your used to extract and grain recipes and tried to apply the same principals to this brew. if your going to stick with AG brewing you may want to invest in an actual mashing tun. also next time you may want to do that second heat to 170 for 10 minutes step in a second pot. Then combine the two worts in your brew kettle.

 

[sbrein1]

I am not sure how much reading you did on the BIAB method before doing your first batch, but the biggest down fall I see is that it is not quite as efficient as the traditional all grain method. If you target AG was calculated assuming the traditional AG method of brewing the difference in OG could easily be chalked up to the difference in methods with the BIOB being less efficient in converting your starches to sugars. If you calculated the OG assuming BIAB method, you make look at how your grains were milled. I am not a professional at this, but the lower gravity means your wort was a bit "wet", which would mean you didn't convert enough of your starches to sugars. If it was the milling that would mean your grain wasn't milled fine enough. I would suggest milling your grains a bit finer next time. Just my opinion though. It could have been several different things.

 

[DoubleAught]

The lower efficiency for the BIAB method makes sense. I bought the grains crushed. Eventually I will invest in a mill and a mash tun to do it correctly. Would my conversion be more efficient if I mashed the grains longer than the 60mins?

 

[TipsyDragon]

not necessarily. The actual conversion of starch to sugar may take less than 60 minutes and mashing for longer may not actually help. I would suggest doing an iodine test to see if the wort has any starches left in it.

What will up your efficiency is even water drainage through your grain bed. If all the water flows from just one portion of your grain bed and not another only the grain that got the water flow will give up its sugar to your brew.

 

[RM-MN]

I am not sure how much reading you did on the BIAB method before doing your first batch, but the biggest down fall I see is that it is not quite as efficient as the traditional all grain method. If you target AG was calculated assuming the traditional AG method of brewing the difference in OG could easily be chalked up to the difference in methods with the BIOB being less efficient in converting your starches to sugars. If you calculated the OG assuming BIAB method, you make look at how your grains were milled. I am not a professional at this, but the lower gravity means your wort was a bit "wet", which would mean you didn't convert enough of your starches to sugars. If it was the milling that would mean your grain wasn't milled fine enough. I would suggest milling your grains a bit finer next time. Just my opinion though. It could have been several different things.

Not true that BIAB is less efficient. I've measured 80% with BIAB and others have exceeded 85%. Most of the difference in efficiency is in the crush of the grain. If it isn't crushed fine enough, the water cannot get to the center of the particles to convert or you can't get the sugars back out if it did.

Try BIAB again but double crush or use a grain mill to get your particle size down. I use a Corona style mill and my grain comes out looking a lot like corn meal but with the grain in the bag, I don't have to worry about a stuck sparge.

 

[DoubleAught]

Not true that BIAB is less efficient. I've measured 80% with BIAB and others have exceeded 85%. Most of the difference in efficiency is in the crush of the grain. If it isn't crushed fine enough, the water cannot get to the center of the particles to convert or you can't get the sugars back out if it did.

Try BIAB again but double crush or use a grain mill to get your particle size down. I use a Corona style mill and my grain comes out looking a lot like corn meal but with the grain in the bag, I don't have to worry about a stuck sparge.

This makes sense to me also. I'll ask if they can double crush my grain next order and I'll see if that helps. Looks like I need to invest in a grain mill....

 

[usfmikeb]

Yep, agree with above post. Something else to keep in mind is that this is your first AG, so it should be a learning period. How good is your thermometer?

 

[DoubleAught]

Yep, agree with above post. Something else to keep in mind is that this is your first AG, so it should be a learning period. How good is your thermometer?

I agree with it being a learning experience and I learned a lot! Thermometer is right on. It's new, but I double checked it with a 2nd digital thermometer to gauge it's accuracy.

 

[TipsyDragon]

I agree with it being a learning experience and I learned a lot! Thermometer is right on. It's new, but I double checked it with a 2nd digital thermometer to gauge it's accuracy.

That doest mean anything. All your devices can be off and need calibration. Get some distilled water, bring it to a boil, then check the temp with your thermometer. It may or may not read 212F (your altitude will affect this temp so look up what it should be at your altituede). Then partially freeze some water and check its temp. The water should be mostly ice crystals with little liquid. Again it may or may not read 32F. I'm willing to bet one or the other reading will be off if not both. You will have to do some math to get the proper conversion factor for your thermometer to get the proper temp.

 

[DoubleAught]

That doest mean anything. All your devices can be off and need calibration. Get some distilled water, bring it to a boil, then check the temp with your thermometer. It may or may not read 212F (your altitude will affect this temp so look up what it should be at your altituede). Then partially freeze some water and check its temp. The water should be mostly ice crystals with little liquid. Again it may or may not read 32F. I'm willing to bet one or the other reading will be off if not both. You will have to do some math to get the proper conversion factor for your thermometer to get the proper temp.

I see

 

[RM-MN]

This makes sense to me also. I'll ask if they can double crush my grain next order and I'll see if that helps. Looks like I need to invest in a grain mill....

You better start saving your money if you are going to get a grain mill like mine. The one I bought cost over $20 (yes, over twenty dollars!) It might take you two or maybe even 3 batches to pay off.

 

[DoubleAught]

That's cheap

 

[RM-MN]

Unbelievable isn't it. Why did I wait so long to start doing all grain. Those 10 extract kits could have been 20 all grain recipes. I found my mill on Ebay and along with the cheap price came somewhat shoddy construction but it does the job just fine and will likely outlast me.

 

[brewtus_]

Make sure you have a really good mixing of your water and the grain when mashing. You probably want to stir the mash a few times over the course of mashing as well. What this does is make sure that every square inch of grain surface area is in contact with the liquid. Efficiency can suffer if you don't.

 

[DoubleAught]

Make sure you have a really good mixing of your water and the grain when mashing. You probably want to stir the mash a few times over the course of mashing as well. What this does is make sure that every square inch of grain surface area is in contact with the liquid. Efficiency can suffer if you don't.

I've been going over my process today and this is one thing I think I didn't do very well. I have a fairly large bag, well it's long but not wide enough. I need to find a bag wide enough to clamp to the sides of the pot to allow me to stir the grain better.