16 replies to this topic

[Poptop]

Fellas, I've done 3 batches with the BIAB set up, so far pretty good.  Setting my estimations in Beersmith at 70% efficiency, my first batch I got 75, the second 63 and Saturday's came in at a whopping 55.  The first was an overnight mash.  The others 60 minutes.  Pretty sure I didn't have any dough balls.  My boil volume must be okay because it's exactly what I expect in the fermenter just as if I used the mash tun.  PH is where I want it to be etc. 

 

I'm inclined to think 60 minutes isn't long enough?  All of these beers were mashed ~ 152.  Any ideas?  

[HVB]

I shoot for 70% and that is what I get 90% of the time. The other 10% is a touch higher. I mash for 40 at me sac rest and the ramp to 165 for 20.

[Poptop]

Should I be holding back a portion of water to heat and add-in/mash-out before hoisting out the bag?

[SchwanzBrewer]

OK, I haven't done BIAB yet, but it should follow the chart below for efficiency.

 

 

There are 4 things that will effect efficiency in no particular order...

 

1. Grist make up... do you have a lot of unmalted adjuncts? Does your malt have the ability to convert the long chain starches from the adjuncts?
2. Temperature... if your thermometer is way off you'll see efficiency problems. This has happened to me where I was mashing at 170 because my thermometer was garbage. If you are 145 - 164 you'll still get conversion but it might take longer.
3. Improper measurement... this is my guess as to the biggest problem in homebrewing. Our measurement devices especially for measuring liquids in larger volumes are crappy at best. We're probably +/-0.25 gal at best and that can account for a point or two. Unless you weigh your water, or have an uber expensive flow meter, prior to mashing you won't know very accurately what you start with.
4. Crush. If your crush is really bad (as in hardly crushed at all), which can happen especially with dorks messing with the mill at the homebrew shop, you won't be able to extract the sugars properly. I'm not arguing or advocating for any size, but if you can't see the starchy inside, then you aren't milling fine enough. I find this is rarely the case, but it's worth looking at.

When you combine these things the errors multiply and so will your final OG and those efficiency calculations go to crap.

 

So, my best advice would be to fastidiously measure your grist weight, water weight, use a calibrated thermometer, and take notes on your next batch.

[Poptop]

All very good points for sure.  The majority of my recipes are very simple.  Adjuncts seldom used.  Measurements haven't changed from tun to bag but I do think I might get a new thermometer.  I am also considering tightening my crush because I'm BIAB currently.  These two items along with a longer mash time might help me find some BIAB consistency, which is something I haven't seen just yet.

[positiveContact]

step 1 is measure the gravity of your pre-boil wort and see how it compares to that chart above.  that will tell you if the problem is conversion.  if the problem is conversion a lot of the suggestions above might help.  crush, mash pH and mash temperature are about the only knobs I know to turn to affect efficiency.  is it possible your scale is off and you are using less grain than you thought?

Edited by pickle_rick, 12 November 2018 - 09:13 AM.

[neddles]

OK, I haven't done BIAB yet, but it should follow the chart below for efficiency.

 

 

There are 4 things that will effect efficiency in no particular order...

 

1. Grist make up... do you have a lot of unmalted adjuncts? Does your malt have the ability to convert the long chain starches from the adjuncts?
2. Temperature... if your thermometer is way off you'll see efficiency problems. This has happened to me where I was mashing at 170 because my thermometer was garbage. If you are 145 - 164 you'll still get conversion but it might take longer.
3. Improper measurement... this is my guess as to the biggest problem in homebrewing. Our measurement devices especially for measuring liquids in larger volumes are crappy at best. We're probably +/-0.25 gal at best and that can account for a point or two. Unless you weigh your water, or have an uber expensive flow meter, prior to mashing you won't know very accurately what you start with.
4. Crush. If your crush is really bad (as in hardly crushed at all), which can happen especially with dorks messing with the mill at the homebrew shop, you won't be able to extract the sugars properly. I'm not arguing or advocating for any size, but if you can't see the starchy inside, then you aren't milling fine enough. I find this is rarely the case, but it's worth looking at.

When you combine these things the errors multiply and so will your final OG and those efficiency calculations go to crap.

 

So, my best advice would be to fastidiously measure your grist weight, water weight, use a calibrated thermometer, and take notes on your next batch.

 

Schwanz has you covered. That chart is your money. If you aren't hitting the expected gravity for your grist ratio then you know you have a problem. 

[denny]

OK, I haven't done BIAB yet, but it should follow the chart below for efficiency.

 

 

There are 4 things that will effect efficiency in no particular order...

 

1. Grist make up... do you have a lot of unmalted adjuncts? Does your malt have the ability to convert the long chain starches from the adjuncts?
2. Temperature... if your thermometer is way off you'll see efficiency problems. This has happened to me where I was mashing at 170 because my thermometer was garbage. If you are 145 - 164 you'll still get conversion but it might take longer.
3. Improper measurement... this is my guess as to the biggest problem in homebrewing. Our measurement devices especially for measuring liquids in larger volumes are crappy at best. We're probably +/-0.25 gal at best and that can account for a point or two. Unless you weigh your water, or have an uber expensive flow meter, prior to mashing you won't know very accurately what you start with.
4. Crush. If your crush is really bad (as in hardly crushed at all), which can happen especially with dorks messing with the mill at the homebrew shop, you won't be able to extract the sugars properly. I'm not arguing or advocating for any size, but if you can't see the starchy inside, then you aren't milling fine enough. I find this is rarely the case, but it's worth looking at.

When you combine these things the errors multiply and so will your final OG and those efficiency calculations go to crap.

 

So, my best advice would be to fastidiously measure your grist weight, water weight, use a calibrated thermometer, and take notes on your next batch.

 

Keep in mind that that chart is for conversion efficiency, not mash efficiency.

[SchwanzBrewer]

Keep in mind that that chart is for conversion efficiency, not mash efficiency.

 

 

Table 1 gives the expected first wort extract/gravity based on the mash thickness at the time that the sample is pulled. To simplify the calculations this table assumes an 80% potential extract content in the grist (which is typical for most base malts) and 100% mash efficiency. Use these numbers as a benchmark for comparing your measured first wort gravities.

 

That quote is direct from Kai's site.

 

I forgot to mention PH in the potential problems.

[positiveContact]

Fellas, I've done 3 batches with the BIAB set up, so far pretty good.  Setting my estimations in Beersmith at 70% efficiency, my first batch I got 75, the second 63 and Saturday's came in at a whopping 55.  The first was an overnight mash.  The others 60 minutes.  Pretty sure I didn't have any dough balls.  My boil volume must be okay because it's exactly what I expect in the fermenter just as if I used the mash tun.  PH is where I want it to be etc. 

 

I'm inclined to think 60 minutes isn't long enough?  All of these beers were mashed ~ 152.  Any ideas?  

 

just curious how you can tell if you have dough balls when the grain is all bagged up.  is the bag left kind of open while you mash so you can properly stir and break up dough balls in the bag?

[neddles]

just curious how you can tell if you have dough balls when the grain is all bagged up.  is the bag left kind of open while you mash so you can properly stir and break up dough balls in the bag?

 

the bag is open at the top of the kettle.

[Poptop]

Yes. The bag is free in the Kettle. Plentiful room and mash movement.

[djinkc]

Are you using a hydrometer?

[Poptop]

Are you using a hydrometer?

 

Yes

[djinkc]

Yes

Then except for everything mentioned above all I have is crush difference and ingredient measuring errors.

[Merlinwerks]

Should I be holding back a portion of water to heat and add-in/mash-out before hoisting out the bag?

 

Maybe, depends on what your target OG is. I usually get 70% - 75% brewhouse efficiency when targeting an OG of 1.065 or less. When trying to get North of that I found the info in THIS article to be very helpful.

[Merlinwerks]

Also, when I am going to reserve some liquor for a "sparge", I first treat the full volume with whatever salts and acid I plan on using and heat it to strike temp then pull out ~3/4 - 1 gal and just let it sit in a pitcher until the mash is done, no need to heat it back up again.