Efficiency question

[gstolas]

I was never quite sure of my efficiency. So I decided to try and get to know it. I ended up with a gravity of 1.040 measured with a refractometer.....twice . this was my preboil volume by the way which is 7 gallons. I'll be checking again since I'm in the middle of this now and not finished yet.

Some calc said based on my grains 11 lbs 2 row , 0.75 lb dark Munich and 0.25 lbs of crystal 55 L and my volume/ gravity......I have 63% efficiency.

I'm not too surprised since my previous batches have missed their targets. I also batch sparge which I think can be a factor vs fly sparging. Milled my grains at the shop. 63% is lower than I would like but I can tolerate it until I upgrade from a 10 gal igloo mash tun

Can anyone give some input? I'd appreciate it

Thanks!

 

[benzesp]

I'd imagine if you fly sparge you will increase your efficiency. When I switched it made a considerable difference. Grab 10 bucks of copper tubing and make a sparge ring, get the flow right and boom.

OR the mill at your shop needs the gap checked.

 

[doug293cz]

Fly sparging may or may not improve your efficiency. Fly sparging is not automatically more efficient than batch sparging. It all depends on your process and equipment. A well executed batch sparge will provide better efficiency than a poorly executed fly sparge. The converse is also true. With efficiencies below about 80% there is a high probability that part of the problem is incomplete starch to sugar conversion. Sparging (no matter what method) will not fix this. Sparging might help a little bit with conversion by effectively extending the mash time and allowing some additional conversion. For best results you want to have complete conversion before you start sparging. Conversion can be improved by crushing finer (which can cause stuck sparges if done too finely), and/or extending the mash time. Crushing finer allows faster conversion due to shorter diffusion distances, and longer times allow more conversion to occur.

For more information on diagnosing efficiency issues, check out my posts here, here & here.

Brew on

 

[gstolas]

Thank You

 

[gstolas]

So longer than the standard 1 hour mash for example? Perhaps 75-90 minute mash? I'm going to experiment some more with my system and see if I can up the efficiency. I've been doing the same method as stated above for most of my batches

 

[hartlesj]

you said your pre-boil was 1.040. What about your post boil? and are you making the right comparison? If your comparing pre-boil measurements to post boil target gravity, your efficiency will show lower than it is.

-Steve

 

[doug293cz]

So longer than the standard 1 hour mash for example? Perhaps 75-90 minute mash? I'm going to experiment some more with my system and see if I can up the efficiency. I've been doing the same method as stated above for most of my batches

Yes. Since every system has its own unique variables, you will need to experiment with yours to find out what works best. Downside is you will have to brew more until you figure it out. Wait!... that's not a downside!

Brew on

 

[doug293cz]

you said your pre-boil was 1.040. What about your post boil? and are you making the right comparison? If your comparing pre-boil measurements to post boil target gravity, your efficiency will show lower than it is.

-Steve

Pre-boil efficiency calculations should match post-boil efficiency calculations, unless you spill wort or add sugar during the boil.

Pre-boil volume * (pre-boil SG -1) should = Post-boil volume * (post-boil SG -1)​

Gravity measurements at the hydrometer calibration temp, and volumes corrected for temp.

Brew on

 

[AK7007]

Efficiency comes from several factors: conversion of starch to sugar, volume losses, and separation of converted sugars from the spent grain.

Braukaiser has a good writeup: http://www.braukaiser.com/wiki/index.php?title=Understanding_Efficiency

If you want to improve efficiency, you need to improve one of those things.

One thing that I have noticed that has made a volume loss difference for me is using a BIAB liner for my cooler. Sure, I could use more grain since it's only like a half gallon difference, but it has also made stuck sparges a thing of the past and helped with gummy mashes. Actually putting my grist into a water calculator and messing with the water calcs helped too.

 

[doug293cz]

Efficiency comes from several factors: conversion of starch to sugar, volume losses, and separation of converted sugars from the spent grain.

Braukaiser has a good writeup: http://www.braukaiser.com/wiki/index.php?title=Understanding_Efficiency

If you want to improve efficiency, you need to improve one of those things.

....

Yeah, I go over the efficiency factors and calculations in the links I posted in post #3 in this thread. One of the links specifically talks about how to figure out where your efficiency issues originate, and things to look into for each possibility. My discussion of the topic is shorter than Kai's, and I think easier to understand (but that may just be "ugly baby syndrome") YMMV.

Brew on

 

[gstolas]

My OG was 1.052 about 5.5 gal. Its where I wanted it to be but I aimed a little higher suspecting my efficiency was low. Thanks guys I'll check those out

 

[gstolas]

I was using brewersfriend efficiency calc to find the preboil . like Doug said, I assumed it didn't matter as long as you accounted for the gravity as well as the volume after the mash/sparge.

 

[brewfun]

Efficiency comes from several factors: conversion of starch to sugar, volume losses, and separation of converted sugars from the spent grain.

The Volume Loss portion of your statement isn't what the OP was discussing. He was discussing kettle gravity, which relates only to Mash efficiency. Volume loss is part of Brewhouse Efficiency, which is a different topic.

The simple check of gravity points in to gravity points out that doug293cz provided is the fastest way to find out if there is a problem with measurement or the actual efficiency.

On the post by Kai, he has charts for conversion efficiency, which is a great way to know when your mash is complete. The second chart on measuring lauter efficiency is equally useful for any sparge method. Using the two together can hone any mash/sparge regimen.

 

[zippy84]

I'm not sure how accurate it would be due to other factors mentioned, i.e. volume loss, conversion rates and such but I use this calculator to give me a ballpark figure - https://brewedbyus.com/info/calculators/gravity/

I enter all the fermentables and tweak the efficiency until the o.g. matches what my actual o.g. was for the brew. I have changed sparging techniques in my biab brew and over the last 2 brews my efficiency has went from about 55-60% up to about 70% which is great considering it's only my 3rd biab. So like I say, probably not the most accurate, but it tells me from brew to brew, if I make changes, what works in terms of better efficiency.

 

[SteveHeff]

I constantly have efficiency issues due to the shape of my mash tun. I use a rectangular unit, that I have fine tuned to 68-71% efficiency. However, I also BIAB and I regularly hit 82-84%. I either purchase less grain and obtain the same OG or the same grain and significantly boost my alcohol levels.

 

[whovous]

Will a longer mash time increase my efficiency? Is there any downside to longer mash times, other than the time spent?

 

[zippy84]

Will a longer mash time increase my efficiency? Is there any downside to longer mash times, other than the time spent?

The difference is negligible. I've looked at experiments that did side by side mashes... 30mins vs 60mins.. think the difference was an og of 1.049 vs 1.050 with an extra 30 mins. I generally mash for 60 mins, I'm sure going over that time the difference is even more meaningless. Good technique is, I'm sure, way more important (in my inexperienced opinion). Don't think there are any disadvantages to longer mashes though, bar potentially losing some heat and having to bring that heat back up during sparge/boil.

 

[doug293cz]

Will a longer mash time increase my efficiency? Is there any downside to longer mash times, other than the time spent?

The difference is negligible. I've looked at experiments that did side by side mashes... 30mins vs 60mins.. think the difference was an og of 1.049 vs 1.050 with an extra 30 mins. I generally mash for 60 mins, I'm sure going over that time the difference is even more meaningless. Good technique is, I'm sure, way more important (in my inexperienced opinion). Don't think there are any disadvantages to longer mashes though, bar potentially losing some heat and having to bring that heat back up during sparge/boil.

If your starch to sugar conversion is incomplete, then a longer mash will improve your mash efficiency, since mash_efficiency = conversion_efficiency * lauter_efficiency. I describe how to calculate conversion efficiency here: https://www.homebrewtalk.com/showpost.php?p=6954099&postcount=24. To get complete conversion in 30 minutes you need a very fine crush (coarse flour or corn meal), a relatively thin mash, and pH within optimal range. For coarser crushes more time is required due to longer diffusion distances for getting water into, and wort out of, larger particles. With coarser crushes mash agitation (usually by recirculation) can improve conversion speed because the fluid shear helps "short circuit" some of the diffusion limitations.

The potential disadvantage of mashing too long, is that it gives more time for the amylase enzymes to chop up poly-saccharides into mono and di-saccharides. Poly-saccharides are not fermentable, and contribute to the maltiness and mouthfeel of finished beers. Mono and di-saccharides are fermentable, so contribute alcohol to the beer, but little in the way of mouthfeel. If you are looking for a drier beer with thinner mouthfeel, then longer mashing won't hurt. But, if you want more maltiness and fuller mouthfeel, then excess mash time can be detrimental. The types of malt in the grist also interact with the potential amount of mono and di-saccharides, so like most things in brewing: "it's complicated."

Brew on

 

[whovous]

Thanks for the replies. I definitely do not want a thinner mouthfeel, so I won't try to improve efficiency by stretching out the mash.

What about simply adding more grain? I realize that has nothing to do with efficiency, but will more grain give me a higher ABV, all other things being equal?

 

[doug293cz]

Thanks for the replies. I definitely do not want a thinner mouthfeel, so I won't try to improve efficiency by stretching out the mash.

What about simply adding more grain? I realize that has nothing to do with efficiency, but will more grain give me a higher ABV, all other things being equal?

Yes.

Don't be too afraid of longer mashes if your conversion efficiency is low. Things like caramel/crystal malts, carapils/dextrin malt, flaked barely, etc. can help maintain mouthfeel and maltiness. Getting the right balance with your system and process will likely take some experimentation. Don't make huge changes in process or change multiple variables at one time, if you want to understand your system well.

Brew on