Mash efficiency, mash temps, mash volumes, am I doing it wrong?

[Jbrew]

Hello all, still a pretty new brewer, been doing it for about 3 months with about 10 BIAB batches under my belt. 1 brew ago I broke my thermometer and moved to a thermocouple thermometer that I can leave in the kettle, this last brew the mash temp seemed to be more consistent, at least according to the thermocouple. This got me thinking as to the accuracy of my previous thermometer, which then Got me thinking about the importance of accurate mash temperatures and other things as well.
So I read about mash temps on byo and the 2 different starches, and how there broken by 2 different temperatures. Also how mash volume has an affect on conversion.
My efficiency hovers around 65-75%, it never seems to be consistent, but I think I can partially attribute my lower efficiency to my water volumes, I always brew so I end up with 5.5-6 gallons in the carboy to account for trub loss.
So here's my questions,
Should I be doing 2 step mashes? I.e. Mashing at approximately 145-148, then raising to the 152-156 range? What effect will this have? A drier beer?
Should I be mashing with the usual volumes of 1.25 qt/lb. of grain and then doing a couple of sparges or mash outs to hit full volume?
And finally, when I pull my brew bag, I generally don't squeeze much since I account for the grain loss volume, but I do a light squeeze to stop the draining a bit quicker, and the bag always feels slippery and slimey like. Is this unconverted starches that I'm feeling?
Sorry for the long post thanks all for any advice.

 

[Oginme]

Your efficiency is not abnormal, especially since you have a planned loss when pouring into the fermenter.

Doing a step mash would result in a slightly drier beer if that is your goal. Mashing with a higher water to grain ratio also leads to slightly lower finishing gravity in my experience. Is this what you are aiming for or are you looking to see if you can improve your extraction (mash/lauter) efficiency?

If you are looking to improve your efficiency overall, the leading cause of lower efficiency is the grain crush. Many people who do BIAB do their own fine crush or double crush to lower the particle size of the grains going into the mash. Ideally, the husks would be mostly intact and the grain kernels would be predominantly about 3 mm (about 1/8 inch) in size or lower.

Most of the time I do full volume BIAB, which tends to lead to a drier finish than when I do a batch sparge process. When I do batch sparge, I try to get approximately equal runnings from both the wort drained from the mash and the sparge step. I do this by taking the amount of water I need pre-boil, subtracting my estimated grain absorption and then dividing the result by 2. That number is the sparge volume. Add back in the volume from grain absorption and that number is the mash volume. Your numbers don't need to be exact, as anything fairly close will work fine.

Another property to look at is your mash pH. If you are not measuring it, you should look into it. Having a mash pH of between 5.2 and 5.6 will maximize the efficiency of the enzymes which are breaking down the starches from the grains into sugars.

Next, addressing your bag 'sliminess', you are most likely feeling the sugars in the wort. If you are not doing a starch test for conversion, now is a good time to look into that. All it takes is some starch indicator solution which can be found at any drug store (iodine solution). This will let you know that all the starches in solution have been converted. You can google details of this simple visual test or look it up in almost any basic brewing book, such as 'How to Brew' by John Palmer.

 

[Jbrew]

I'm actually not so much looking to make my beers any drier, I'm just curious as to what the little differences that the mash temp and mash volumes make. All my beers have turned out ok, some better then others.
As for water ph, I'm not sure actually what it is, but I do think it's low, because I feel like I remember my pool being low after filling and testing it.
I have iodine tincture, I have done starch tests, but not always. Sometimes it comes up black so I'll the mash run longer, other times it passes.

 

[Morrey]

Oginme has laid out a pretty comprehensive process for you to review.

I think you are wise to look for consistency in efficiency rather than big numbers but all over the place. I'd rather be 75% all the time than 70% one brew and 85% the next.

IMHO, grain crush (fine is fine) rules the efficiency domain in BIAB. Ph is important too so be mindful.

If you get your single infusion mash temps close, and focus on grind and ph, you'll be consistent.

BTW, you are leaving the "cream" in your grain bag by not squeezing. I pulled my bag and took a refractometer reading while it began draining. 1.057. I let drain then squeezed the bag like it owed me money. I think Wilser would have said don't bust my bag! In the end my gravity had risen to 1.059. All those sugars hang around the grain particulate and need some encouragement to move on into the wort! Squeeze that thang!!!

 

[marjen]

I am going to figure a 70% efficiency just to be safe. Looks like that should get me to about 6.5 ABV which would be great. Even if I only hit 65%, that should still be about 6.0 ABV. 6-7 is the sweet spot I am looking for.

I will probably squeeze the bag to try and get everything i can out. I am going to do a full volume mash. So fill it up to a little over 7.5 gallons, sounds like I will probably lose about 1 gallon leaving me with 6.5 for the full boil.

Can I start to raise the heat as soon as I pull the bag, even though it will still be draining into the kettle?

 

[Morrey]

I am going to figure a 70% efficiency just to be safe. Looks like that should get me to about 6.5 ABV which would be great. Even if I only hit 65%, that should still be about 6.0 ABV. 6-7 is the sweet spot I am looking for.

I will probably squeeze the bag to try and get everything i can out. I am going to do a full volume mash. So fill it up to a little over 7.5 gallons, sounds like I will probably lose about 1 gallon leaving me with 6.5 for the full boil.

Can I start to raise the heat as soon as I pull the bag, even though it will still be draining into the kettle?

Right on track! 70% is a safe starting point.

7.5G is fine. You may lose a full gallon, but if not and you get a bit more wort than anticipated, simply boil it off to hit your vol into fermenter. (I lose .5G in my grain absorption w/average grain bill)

Assuming you are on a burner...if not disregard if electric. You can fire your burner while the bag is draining but be careful the flames don't singe you as you hover near the kettle squeezing. I personally don't see this as necessary since your wort is still hot and the boil is forthcoming. You won't save much time in the long run vs the risk of being burned.

 

[Jbrew]

Starting last batch I had my grain milled twice, and I came out with 75% efficiency, with only a dough in stirring and a mashout step, which I'm pretty happy about, just as long as I can start to maintain some type of consistency.
I will test the ph of my water and begin to rectify it as I have a feeling that it will be off.
As for bag squeezing, are latex gloves ok to use? Or will they leave a flavor in the mash?
As for getting back to mash temperatures, what differences do higher mash temps vs lower temps impart on the finished beer?
Thank you all again

 

[Morrey]

Starting last batch I had my grain milled twice, and I came out with 75% efficiency which I'm pretty happy about, just as long as I can start to maintain some type of consistency.
I will test the ph of my water and begin to rectify it as I have a feeling that it will be off.
As for bag squeezing, are latex gloves ok to use? Or will they leave a flavor in the mash?
As for getting back to mash temperatures, what differences do higher mash temps vs lower temps impart on the finished beer?
Thank you all again

I use thin cotton gloves with a pair of latex gloves over top. No notable off tastes that I've detected. I use this same setup to hand pull hot BBQ butts after cooking.

2-3ml of lactic acid in your full volume strike water (7 to 8G) is usually sufficient provided your source water is around 7 ph. You'll probably dig into water chemistry soon enough, but right now you are hammering out the basic process of brewing beer!

Single infusion mashing high at say 155F is typically done for beers when you want a richer mouthfeel and a bit less fermentable sugars for slight residual sweetness. 148F creates more fermentable sugars resulting in a drier beer with a more thin body or mouthfeel.

 

[pricelessbrewing]

@R56brews @Morrey

The pH of your water is only one component of mash chemistry, and a relatively less important one at that. What minerals are in the water, and how much is usually more significant.

It's not worth guessing at water chemistry, if you don't have a full report of the water.

 

[masskrug]

I'd say you are doing pretty well. I have tested my water, add chemicals as needed, dialed in my water volume and I consistently get around 62% efficiency.

 

[RM-MN]

I'd say you are doing pretty well. I have tested my water, add chemicals as needed, dialed in my water volume and I consistently get around 62% efficiency.

You may want to adjust your mill or buy a mill of your own to increase the efficiency or you could just be satisfied with the consistency and efficiency you have. With BIAB and finely milled grain, 80% with no sparge is quite easily achieved.

 

[whovous]

If your hands are clean, is there really any reason to wear gloves to squeeze the bag? After all, boiling is the next stop. Excessive heat is the real reason I can see, but a pair of latex gloves won't help much on that front.

 

[pricelessbrewing]

If your hands are clean, is there really any reason to wear gloves to squeeze the bag? After all, boiling is the next stop. Excessive heat is the real reason I can see, but a pair of latex gloves won't help much on that front.

Sticky wet hot bag makes for sticky wet hot hands.

 

[Jbrew]

The latex gloves helped a little with the heat. I can't keep a continuous squeeze with them but I can at least get a better longer squeeze then with out them all together.

 

[violinguy]

A quick question regarding efficiency. Didn't want to start a new thread.

What would cause a low brewhouse efficiency (59) after a good conversion efficiency (78)? Besides grain crush and water calculations, is there anything else I can improve? I already know I need to do a better job at accurate volume numbers. For this brew day, I held back 1.5 gallons (of a 3 gallon batch so just over 4.5 pre-boil volume needed) and dunk sparged. I only wound up with about 2.75 gallons in fermenter so obviously there was some loss. I figured the sparge would help but it really didn't. sad face

 

[RM-MN]

A quick question regarding efficiency. Didn't want to start a new thread.

What would cause a low brewhouse efficiency (59) after a good conversion efficiency (78)? Besides grain crush and water calculations, is there anything else I can improve? I already know I need to do a better job at accurate volume numbers. For this brew day, I held back 1.5 gallons (of a 3 gallon batch so just over 4.5 pre-boil volume needed) and dunk sparged. I only wound up with about 2.75 gallons in fermenter so obviously there was some loss. I figured the sparge would help but it really didn't. sad face

Did you account for losses between the mash and the fermenter? There will always be some loss in the grain, you can't get all the wort out no matter how hard you squeeze. If you left any trub behind when you transferred to the fermenter that has to be counted as a loss too.

Your sparge did help. Without that you would have left sugars in the grain and probably even less volume into the fermenter. If you had 4.5 gallons into the boil pot and only got back 2.75 into the fermenter you either boiled off more than necessary or left trub in the boil pot. As I do my boil I only lose about half a gallon to the boil and nearly no trub left in the pot as I try to get all but the thickest trub into the fermenter.

Good conversion efficiency should be in the high 80's to low 90's. You might need to crush finer and/or mash longer.

 

[violinguy]

Thank you. I'm pretty new at BIAB. My first batch went well but I broke the hydrometer before I could get any readings. Tastes good, so I must have done something right. I'm going to see about getting a double crush on grains going forward. Also, my water volume numbers need to be tighter. I've already figured out how to do better that way.

On a positive note, at 18 hours I'm getting good activity in the fermenter.

 

[pricelessbrewing]

A quick question regarding efficiency. Didn't want to start a new thread.

What would cause a low brewhouse efficiency (59) after a good conversion efficiency (78)? Besides grain crush and water calculations, is there anything else I can improve? I already know I need to do a better job at accurate volume numbers. For this brew day, I held back 1.5 gallons (of a 3 gallon batch so just over 4.5 pre-boil volume needed) and dunk sparged. I only wound up with about 2.75 gallons in fermenter so obviously there was some loss. I figured the sparge would help but it really didn't. sad face

Looks like you're using palmers definition of conversion (which is typicalled called mash efficiency), or your calculations are flawed. What did you use to evaluate?

For obvious reasons, I'll suggest
https://pricelessbrewing.github.io/BiabCalc/#EfficiencyEvaluation
and the accompanying
https://pricelessbrewing.github.io/methods/Efficiency/

Conversion: Variables are dough in, mash temp, crush, and mash pH. Typical values ~90-95%.

Lauter: There's an initial lauter due to your strike volume, and a sparge efficiency due to your sparging process. Typical no sparge value 75-85%. Typical batch sparge value 85-90%.

Otherwise you have the flat lauter efficiency variable of mash tun loss, and the difference between mash efficiency and brewhouse efficiency, kettle loss.

 

[enkamania]

Sticky wet hot bag makes for sticky wet hot hands.

Is this a quote from Confucius?

 

[violinguy]

Looks like you're using palmers definition of conversion (which is typicalled called mash efficiency), or your calculations are flawed. What did you use to evaluate?

I used the calculators at brewer's friend. However, I'm pretty sure some of the calculations were a result of GIGO (garbage in garbage out) because I don't have very accurate readings of water volume and zero readings of water chemistry. I am making arrangements to fix this before the next batch. :fro:

 

[Jbrew]

I'm still new, and use beer smith, but I haven't really used it much to determine my water volumes. Instead I've just been using the brewers friend mash schedule for determining strike temp and the mash out temp and volume. I've always just followed a half a quart per pound of grain for loss and always figure a half gallon of trub loss in the fermenter and it always been pretty consistent in final volumes. I'm lucky, my kettle has markings to help keep track of water amounts, so that helps quite a bit as well.
As for efficiency, I began this thread thinking that I was getting low efficiency but it seems others are getting lower then me. One other big thing that changed my efficiency before adjusting grain crush was the type of bag I was using. I went from a paint strainer clamped off because it wouldn't fit around the rim of my kettle to a wilserbrewer bag which now allows me to stir thoroughly during dough in. Having plenty of movement, and the ability to thoroughly stir has really helped.

 

[doug293cz]

A quick question regarding efficiency. Didn't want to start a new thread.

What would cause a low brewhouse efficiency (59) after a good conversion efficiency (78)? Besides grain crush and water calculations, is there anything else I can improve? I already know I need to do a better job at accurate volume numbers. For this brew day, I held back 1.5 gallons (of a 3 gallon batch so just over 4.5 pre-boil volume needed) and dunk sparged. I only wound up with about 2.75 gallons in fermenter so obviously there was some loss. I figured the sparge would help but it really didn't. sad face

It sounds like you are using "conversion efficiency" to mean mash efficiency. 78% would be a terrible conversion efficiency (good is 95% or better). 78% isn't really even a very good mash efficiency for a moderate gravity brew when sparging. If your brewhouse efficiency is significantly less than your mash efficiency, it's because you are losing (leaving behind) significant volume somewhere.

Read my post here, to learn what all the different efficiencies are, and how they relate to each other. By knowing what affects the different efficiencies, you know the kinds of actions that can improve them.

Brew on