Low Efficiency - How to improve

I am making mostly 4.5 - 5% IPA's Blonde Ale's and Pilsners which I make from either all grain kits or AG recipes and are generally around 5 - 6kg of grains. I mash in a 30L Brew Monk with 18L water - there is about a 4.5l dead space and I sparge up to 28L. I usually end up with 24L after boil

I am very careful with temp control and mash for 1 hour+ and same for boil. I check conversion with iodene and all seems good.

However I never seem to hit the expected SG - the last brew for example should have been 1.052 but was 1.044. I also used an efficiency calculator (Brewers Friend) which was telling me my efficiency was around 65%.

I get my grains crushed from Malt Miller so assume there would be no issue there so how can I improve this and should I bother - I don't care if the ABV is a bit lower than expected but if there are some things I can do it would be good - would improved efficiency improve flavour? I was wondering if a full volume mash would improve things or not.

Any advice welcome

Thanks

David Woods said:

However I never seem to hit the expected SG - the last brew for example should have been 1.052 but was 1.044. I also used an efficiency calculator (Brewers Friend) which was telling me my efficiency was around 65%.

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This is the problem with AG brewing - everyone gets different efficiencies so trying to replicate a recipe from someone else is so much harder because of all the variables. I would say it's more important to have repeatable effiiciency rather than a high efficiency, as you can plug that into your recipe calculator. Remember that having lower effiiciency just means you need to add a bit more grain, so it doesn't cost a lot - but you just need to know about it before you start the mash.

Efficiency can depend on a number of things but the biggest variable I've found is the grain source & crush. I'm currently getting 66% with the latest batch of grain from The Homebrew Company, Malt Miller's was the best I got around 72%, and I had one batch of grain from another supplier that was as low as 60%. Even batches of grain from the same supplier can vary as they are crushed at different times.

So don't worry about it too much, keep records of your brews and if you get 65% each time then plug this into your brewing app and it'll adjust the amount of grain to give you the target OG.

I brewed this morning brewzilla 3.1.1, 5kg of pilsner malt from crips water 22L mashed for 1 hour sparge 8L water that leaves me with 26.9L for the boil' og 1052

I do this recipe quite a lot and always hit the ball park 1050 1052

This is the hops after whirlpool using the paddle

My efficiency went up when I got a grainmill and started doing it myself.

The malt you get can also make a difference. Five pounds of my previous pale ale malt got me 1.040 in a three gallon batch. I got a bag of Crisp #19 floor malted maris otter and started getting 1.050.

Doing a mash out should give you the missing 0.008 because sugar stuck to the grains will release into solution when heated.

Full volume mash would be much worse because of diluted enzymes.

David Woods said:

around 5 - 6kg of grains. I mash in a 30L Brew Monk with 18L

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That is a full load. It will compact.
You need to think about circulation flow and length of time.
Perhaps stirring might help.
Perhaps rice hulls
Perhaps a grinder (later), but I think you can get a lot closer before that.

David Woods said:

I was wondering if a full volume mash would improve things or not.

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Yes

Check crush, check pH, measure gravity temperature corrected at end of mash, post sparge / pre boil and
Post boil.
Include volumes in your gravity and then you can work out mash efficiency, lauter efficiency and brew house.
Then you can find out where the efficiency can be tweaked.
If your sparge is quick then you have to consider channeling or not crushed enough.

MashBag said:

That is a full load. It will compact.

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Following from this, how well do you stir/mix your mash? Have you made sure you don't have and dough balls?

I usually get 75% brew house efficiency with my Mundschenk unless I make a wheat beer when it drops dramatically. I only buy crushed grain usually Crisp.
However stirring the mash is critical especially when mashing in to ensure no doughballs. I recirculate for the whole 60 minute mash and stir every 10 minutes. The grain to water ratio will also affect the efficiency, I now have a ratio of 3 to 1 I.e. for 5kg of grain then 15 litres of water. The dead space on the Mundschenk is 7 litres so recirculating the water is key, without a pump this difficult but it can be done manually. Sparring is also important as no sparge will lower your efficiency.

David Woods said:

I am making mostly 4.5 - 5% IPA's Blonde Ale's and Pilsners which I make from either all grain kits or AG recipes and are generally around 5 - 6kg of grains. I mash in a 30L Brew Monk with 18L water - there is about a 4.5l dead space and I sparge up to 28L. I usually end up with 24L after boil

I am very careful with temp control and mash for 1 hour+ and same for boil. I check conversion with iodene and all seems good.

However I never seem to hit the expected SG - the last brew for example should have been 1.052 but was 1.044. I also used an efficiency calculator (Brewers Friend) which was telling me my efficiency was around 65%.

I get my grains crushed from Malt Miller so assume there would be no issue there so how can I improve this and should I bother - I don't care if the ABV is a bit lower than expected but if there are some things I can do it would be good - would improved efficiency improve flavour? I was wondering if a full volume mash would improve things or not.

Any advice welcome

Thanks

Click to expand...

The thinner the mash the better the conversion. Grain crush, all the grain kernels have to be cracked for the enzymes to get to the starch, which is almost impossible without crushing the grain to fine.
I would do as suggested above and concentrate on consistency, try and improve on the lautering efficiency if you are happy with your mash temperature being stable throughout then I suspect the culprit is the lautering.
Full volume will improve the conversion of starch and keep a stable mash temperature throughout the mash period, mash out, and no sparge will arguably give you a better beer, evading any tanning issue. The only thing to be aware of is getting as much as the wort from the grain as possible.
You may need a little extra grain if you consider full volume but it is worth it.

Most of my grain comes from malt miller ready crushed and I find my gravities are pretty spot on to Brewfather predictions (within a small number of points) and pretty consistent. How are you measuring your gravity? I've found cheap hydrometers to be pretty rubbish, though the error is usually around the 5 point range so less than the shortfall you're seeing, but one thing to check out. If you'e using a refractometer then make sure its one calibrated for wort and not fruit juice or something else, again only probably worth several points but something easy to go around.

Then you're into the best practice for mashing I guess...dont rush it, plenty of stirring, making sure you have no dough balls. Not sure extraction is that sensitive to temperature control, as long as you're between about 50 degrees and 72 degrees you should extract all the sugars, the specific temperer then is all about the conversion. Obviously if you go too hot then you risk de-naturing beta amalyse but that shouldn't impact your headline gravity.

Its tricky to chase sometimes...My mate and I have exactly the same Brewzilla set up in our garages and live very close to each other so exactly the same brewing conditions and yet my Brewzilla is always lower on extraction by a good 5 or more points...I've just accepted it and set the efficiency lower in Brewfather to compensate...just calls for a few extra grams of malt so no great shakes at the end of the day. As long as your miss is consistent, i.e. your process is consistent, then just adjust for your actual efficiency and crack on.

Milling your own grain just adds another variability into the mix...best to make sure the rest of your process is dialled in before introducing more variables...Just change one thing at a time until you isolate the variable that is making the difference.

65% is nothing to complain about. Adjust the recipe to that.

Agentgonzo said:

Following from this, how well do you stir/mix your mash? Have you made sure you don't have and dough balls?

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Absolutely stir stir the mash thoroughly at the start, until properly smooth.

hoppyscotty said:

ready crushed and I find my gravities are pretty spot

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Yes indeed. Milling your own isn't the solution here.

hoppyscotty said:

cheap hydrometers to be pretty rubbish,

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Phew. I really did think it was me being pedantic. Nice to here someone say that out loud.

Something else to note, and I am not sure about the facts here.. Do you treat your water?

I will add that electronic more expensive hydrometers are great, my milwaukee very accurate, checked regularly against hydrometer and calibrated. I do let the wort or beer cool. A lot cheaper than an Anton paar hydrometer.

There's a real balance between mash efficiency which should be at least 90% ( normally high for most mashes), but that doesn't help if your lauter or brewhouse efficiency is low.

Mashing overnight is touted as a way to sometimes help mash efficiency, sparge with loads of water will improve the extraction but then you have loads of dilute wort to boil down.

Deciding on where your loss is the start to improvements.

The finest crush your unit can cope with is one aspect, I use glucanase in all my mashes to help the flow.
Oats, rye and wheat will all reduce your extraction.

A homebrew scale one of these would change all of our numbers.

https://www.brewmation.com/brewing/mash-press

MashBag said:

That is a full load. It will compact.
You need to think about circulation flow and length of time.
Perhaps stirring might help.
Perhaps rice hulls
Perhaps a grinder (later), but I think you can get a lot closer before that.

Click to expand...

I find rice hulls to be a game changer. I use about 5% of the grain bill and pretty much always overshoot on OG. By quite a margin too. 1045 - 1052, 1066 - 1072 etc.

David Woods said:

I am making mostly 4.5 - 5% IPA's Blonde Ale's and Pilsners which I make from either all grain kits or AG recipes and are generally around 5 - 6kg of grains. I mash in a 30L Brew Monk with 18L water - there is about a 4.5l dead space and I sparge up to 28L. I usually end up with 24L after boil

Click to expand...

That's a heavy grain bill in a 30l mash tun. I know because I've done similar in a 30l and I would increase the water volume to the point where it's not a huge effort to stir the grain. Last time I did that size of a grain bill (5.3kg including rice hulls) I used 21l of water. Your mash isn't going to be efficient if it's almost dry in spots. Recirculation might help, but I wouldn't bank on it.

I also vorlauf a lot (10l minimum) after the mash is finished and before sparging and then sparge to 30l or thereabouts. Boil off brings me back to 23-24l and then I almost always find I have to add water to hit the target OG. In the above case it was almost 4l of water added.

One final point and this might not be a problem for you, but I find that the temperature control in my Klarstein is very poor. So much so that I don't use it any more. Instead I prepare my water in a Burco (adding any treatment there) and heating to the strike temperature plus VAT. So 66° mash with ~5kg grain will need ~73° water. I transfer as much as I need to the mash tun and stir in my grains and keep stirring and checking the temp with a stick thermometer until I'm satisfied I've hit the target. I insulate the tun and lid and then stir and check every 20 minutes. Usually I don't get more than a 1° difference from start to finish. If there is a noticeable drop, I'll use the 1500w element to heat for a few minutes, stirring and checking until everything is back on track. This is usually only necessary if I'm doing a 90 minute mash.