Another Question about BIAB

[AngryAndy]

Hi all. About two weeks ago you guys answered a tone of questions for me about the mashing process. I'm going to be trying BIAB shortly and was about to buy a bag on OBK.com. I remember from the last thread, that the short answer was to raise the bag after mash, let it drain, squeeze it like it owes you money for efficiency and no need in trying to batch sparge/rinse the bag'o'grains.

Well on OBK.com, I was reading the description of the bag and saw the following statement. "Most people will prefer to increase the grain bill to compensate for not rinsing the grains after the mash." So, now my question is, is this correct? I mean if so- how am I going to compensate for the lack of not rinsing after the mash? OR is this nonsense. (Here's the full link.) https://www.ontariobeerkegs.com/21_...Bag_Brew_in_a_Bag_p/poly-large-biab-21x30.htm

For instance, take this simple all-grain recipe in the recipe section of this site. It's an american amber ale.
Grain:
9 lbs. American 2-Row Malt
2 lbs. Crystal/Caramel Malt 40L
2 oz. Roasted Barley

60 minute mash @ 154.

Hops:
2 oz. Willamette @ 60 minutes

Do I need to jack up the base malts from 9 pounds to something else? 10, 11, 12 10000lbs? I don't know! If so whats the calculation? Or am I fine following the recipe and disregard what OBK.com was talking about?

 

[Yalc]

I would usually get about 70% efficiency from my BIAB, no sparge. If you anticipate efficiency much higher than that you might not get the OG you are looking for. Be conservative on your first until you get an idea of how your system performs.
It will depend on your grain crush and how well you maintain your mash temp for the 60 minutes of mashing.

 

[pricelessbrewing]

Almost all recipes are standardized and based on 70% mash efficiency.

Most BIABers that squeeze, and don't sparge, get at least 70%. Average is about 75% though +-5-6%, so I wouldn't worry about it until you have more information on your system. You can however estimate it using my mash calculator if you want to see what sort of thing you can expect. Copy the text below, paste it into the "Saved Data" text box, click Data functions, then click Import Data. It should estimate the gravities, volumes, and efficiencies. You can adjust the variables, like mash thickness or grain bill, to see how it impacts the efficiencies.

5,13,57,0,60,154,72,168,0,0.08,0.0014,1,9,13.898,0,0.5,0,95,grams,0,InitiAle,Stout,1.0650,2-9,36,100,0.00,1.000,1.000

Example scaling:

American amber ale, expected efficiency 73.6% 1.069 OG (5 gallon batch size)

Grain:
9 lbs. American 2-Row Malt
2 lbs. Crystal/Caramel Malt 40L
2 oz. Roasted Barley


American amber ale, expected efficiency 78.3% 1.050 OG (5 gallon batch size)

Grain: (new total: 9.454, let's just call it 9.5lb, so take out 3.5 lb of base malt).
5.5 lbs. American 2-Row Malt
2 lbs. Crystal/Caramel Malt 40L
2 oz. Roasted Barley

 

[AngryAndy]

Priceless- I'm so sorry. I'm totally lost. I don't understand.

 

[AngryAndy]

Yalc- Let me see if I have this, or at least some elementary understanding. Your saying that with most of these all-grain recipes, if I use the BIAB method I should expect about 70% effieincey. If I was going to do it all-grain and sparging etc, I could expect to hit roughly 75%. When I do the math on these different calculation websites I learn the following:

1) If my OG in the Amber Ale is suppose to be 1052 my efficiency should be 74.56%
2) If my OG in the Amber Ale is suppose to be 1052 and I do BIAB my efficiency will be around 70.26% with only an OG of 1049.

So try it out following the exact recipe and see what happens. The difference in efficiency and OG's of 1049 vs 1052 is literally 0.39% abv.... If I really am losing sleep over it I could bump up the 9lbs of 2-Row to 10lbs (I know this isn't the exact math but I'm in the ball park).


Is this right?

 

[oujens]

What I understand is you do experience a loss in efficiency compared to sparging, but that can be offset with a finer grain crush. And maybe squeezing. I mill tight and squeeze a little to get 78-80% BH efficiency.

 

[pricelessbrewing]

Adjust your basemalt to hit the gravity you want. As your grain bill decreases, you gain some efficiency. This can be pretty hard to wrap your head around, but if you go to my mash calculator and change the variables and see what happens, it might make more sense.

 

[doug293cz]

Your mash efficiency is a combination of your conversion efficiency and your lauter efficiency (mash eff = conv eff * lauter eff.) Lauter efficiency is deterministic for no-sparge and batch sparge processes, meaning they can be predicted with good accuracy. Conversion efficiency (what percentage of the starch you actually convert to sugar in your mash) can be highly variable. With a fine crush, you can readily hit 95% - 100% conversion efficiency. With too coarse a crush, conversion efficiency can fall into the 70's. It's easier to control the crush if you have your own mill. If you don't have your own mill, you are at the mercy of your grain supplier, and many suppliers have notoriously poor crushes.

Your best bet is to just brew your first batch according to the recipe, and take accurate measurements of grain weight, water/wort volumes, and SG's. If you are doing no-sparge, the important measurements are grain weight, strike water volume, pre-boil SG, and pre-boil volume. If you collect these measurements and put them in Priceless' calculator, it will tell you what your actual conversion, lauter and mash efficiencies were. If your conversion efficiency is less than 90%, then you really need to do something about your crush (or resign yourself to buying extra grain to make up for poor conversion efficiency.) You can easily improve lauter efficiency by squeezing the bag more aggressively (in order to reduce the grain absorption rate), or adding a sparge step.

Once you know your actual efficiencies, you can decide how to proceed for future brews, whether it's recipe adjustments or process changes.

Brew on

 

[Sadu]

All grain recipes are based around an efficiency, though they don't always say what that efficiency is. Most are based on 70% as a general standard.

For your first brew you don't know what your efficiency will be - so just go with the recipe. After your brew is done measure the OG and how much volume you have and you can enter that + your recipe into a calculator to figure out what your efficiency was for that batch.

I got 72% on my first batch, so pretty close to the recipe, and this is how it should be. Don't need to adjust anything. If you were to get say 75% then you are going to have either more gravity or more volume than the recipe states, and things can get unbalanced. This is where you might want to use less grain next time so you finish closer to the recipe. Likewise if you end up with 65%, you will want to use more grain next time.

Once you have done a few batches you will get a better idea of whether any adjustments are needed.

Most people find that BIAB with a sparge of some sort will increase efficiency by 5-10%. It's up to you to decide whether the extra time / hassle / equipment is worth it to save a few dollars worth of grain.

Most people get less efficiency than normal on high gravity beers. So if you are normally getting say 75% on a 1.048 bitter, you might plan on getting 65% on a 1.089 doppelbock.

 

[eadavis80]

I'd brew the recipe as is and use the method you're most comfortable with the first time through. Only through experience on your own system/equipment will YOU truly see what type of efficiency you get.

 

[Chris_Primavera]

The other important piece that is not being discussed here is water volume. Find a good BIAB calculator, measure accurately and save your data. Efficiency cannot be accurately calculated without accurate volume measurement, especially strike water needed, and volume of ambient wort.

 

[brew703]

If you are worried about efficiency, then add 10% more grain and that should compensate for the loss. I used to worry about that but not so much now.
I regularly get 70-75% efficiency and I am satisfied with that.
Water volume is important as is boil off rate.
I brew 3.5 gallon batches and with my system boil off is .9-1.1 gal/hr depending on humidity.

 

[soccerdad]

Another thing to consider in getting more complete conversion is a longer (like 90 minute) mash. This is especially critical when you CANNOT control the crush of the grain. So if the LHBS gives you coarse grain, try mashing longer in order to fully saturate the grain. Personally, I would do this prior to adding base malt (because it has worked for me), but you have the option of doing what you want to do.

 

[brokebucket]

There is a lot of good information here that will be completely lost on you until you ACTUALLY brew your first BIAB. My recommendation would be to just brew to the recipe you want and see what happens. Here is the easy peasy first timer BIAB way to go about it:

-pick a recipe that you can whiff on the OG a bit and not worry too much about. Anything in the 1.050 to 1.060 range that doesnt have a ton of hops would be good. Think simple pale ale, porter, brown ale type beers.

-find a way to plug your recipe in to some BIAB software to figure out strike temp and water volume. Go with these numbers. (I use beersmith, but there are a few free ones).

-Brew it! Relax and enjoy it, but pay attention to your preboil and post boil numbers. Also, pay attention to where your strike water temp started and your mash temp ended. Writing this stuff down is always smart.

-Hopefully, you will get in the wheelhouse of your numbers, but you will probably miss on one or two. Dont worry too much about it just yet, as you need to tighten up your process as you go.

In summation: worrying about a problem you don't have yet is unproductive. Brewing is fun, right?!? The good news is if your numbers are ballpark and you manage your temps (mash and ferment), it's really hard to make bad beer. Adjustments can be made after the fact.

Enjoy!

 

[AngryAndy]

I want to thank all of you for the advice. I have printed this thread off and will be using it to work my way through my first BIAB. Thanks again.