Terrible Efficiency

[cliffo]

Hi Guys,

I've done several AG brews now and am yet to get any better than 60% efficiency.

I think this may be related to the fact that at present I am limited to doing the boil in a BigW 19L pot, hence not be able to extract all the sugars fromthe grain with a limited batch sparge.

I usually mash at a 2.5:1 ratio (water:grain) and using Beersmith, it tends to suggest around a 8-9L sparge for my boil size (15L). 60 minute mash, usually around 66-67 degrees. I do the boil and top up the fermenter to 20L with water (all numbers punched into Beersmith).

Can anyone advise if this would be the reason for such low efficiency?

Not really in a position to get a larger pot and do full boils due to limited space. Guess upping the grain bill would be a way around it in the interim?

Apart from that, the beer is tasting fantastic and I am certainly glad I made the jump to AG.

Regards,
cliffo

 

[DJR]

8 or 9 L of sparge water should almost be enough, you should be hitting at least 65% fairly easily. Mind you with a preboil size of 15L for a 20L batch you're not going to be getting all the sugars out. I guess the grain tastes really sweet when you finish.

How's the crush? How are you sparging? When do you measure the efficiency? What's the post boil loss that you have, ie how much is left in the kettle when you finish? Have you tried adding some calcium to the mash (gypsum or ca chloride)?

If it gets too hard, it's pretty cheap to add an extra kg of grain, but long term it does get annoying spending more per batch. I'm happy with 87%, i got there from about 75% on my first AG's with some help by reducing my crush gap, adding salts to every batch and acidifying the strike water slightly with citric acid and sparging with slightly hotter water so i hit 75C sparge every time.

To check if it's the crush, get your shop to run the grain through the mill twice.

Another thing you could do if you have limited boil capacity is get a 2nd pot and run some of the 1st sparge into it and then the 2nd sparge into it, do a boil of both and then add them both together... or you could just buy a bigger pot. Robinox ally pots are nice and go for about $80 to $100 for a 40 or 50 L pot.

 

[matti]

You hit the nail on the head.

Unless you can work out how to concentrate the run off from batch sparging, you need to do half batches or get a larger kettle.

Get a 50 Litre kettle minimum.

The maximum grain for a 19L stockpot is about 2.5-3 kgs .
I used 3 kilos and sparged to 18 Litres once.
HIGH RISK FOR BOIL-OVER!!!
matti

 

[Stuster]

If you're only doing small boils and topping it up in the kettle, you're pretty much bound to get lower efficiency. One option is to sparge with a few more litres, and keep the last few litres to the side. Then top up the boil as you go until the last 15 minutes or so. Should get you better efficiency. Any you have left over you can boil separately and use for starter wort.

 

[bear09]

Hi Guys,

I've done several AG brews now and am yet to get any better than 60% efficiency.

I think this may be related to the fact that at present I am limited to doing the boil in a BigW 19L pot, hence not be able to extract all the sugars fromthe grain with a limited batch sparge.

I usually mash at a 2.5:1 ratio (water:grain) and using Beersmith, it tends to suggest around a 8-9L sparge for my boil size (15L). 60 minute mash, usually around 66-67 degrees. I do the boil and top up the fermenter to 20L with water (all numbers punched into Beersmith).

Can anyone advise if this would be the reason for such low efficiency?

Not really in a position to get a larger pot and do full boils due to limited space. Guess upping the grain bill would be a way around it in the interim?

Apart from that, the beer is tasting fantastic and I am certainly glad I made the jump to AG.

Regards,
cliffo

Im in the same situation with space. I had the same dam problems. I would eagerly be expecting 1055 and end up with 1043. The major thing I changed was the sparge method.... Piss the batch sparging right off. Go continuous. You dont need fancy devices. I hope you know what continuous means.

Changing to continuous improves efficiancy - thats a fact. Give it a try - read some of palmers online 'How to bre" for more info.

Cheers!

 

[Screwtop]

Why not shoot for a 90 min boil so you use heaps of sparge water and get max eff. Sparge 3 times and mix the sweet wort together back and forth a few times in a couple of 19L Bunnings pails, that would average out the gravity somewhat, but not that important. Boil half the (somewhere around 32L) of wort in two batches. Transfer the first batch to the kettle and start the boil adding the hops for the full batch, when finished boiling the first batch transfer it to a cube and tip the hop trub out of the kettle, then put batch two into the kettle and boil, afterwards transferring it to the cube also. Allow to no chill and then into fermenter as usuall.

 

[bayWeiss]

I am not sure I understand what the problem is here. What does mash efficiency have to do with batch size? One can get high efficiencies in fairly small batch sizes.

Even if you are topping up your 15L batch to 20L, your efficiency does not change. Your gravity will definitely change, but not your efficiency.

Make sure to take careful preboil volume measurements, and use this to determine what your efficiency is. What you do after that (add water, or boil hard) will have no effect on well you extracted sugar from your grains.

As far as not being able to boil a full batch, I solve this problem by splitting my batch into two, and then bringing them back together into the fermenter at the end. My stove does not have enough power to boil 20L+ vigorously.

...

Changing to continuous improves efficiancy - thats a fact. Give it a try - read some of palmers online 'How to bre" for more info.

Cheers!

I do not think that is a fact. It really depends on mashtun design... Many batch spargers can (and do) get better efficiency than fly, if the flyer's mash tun filter is not designed or implemented well.

cheers!

 

[Insight]

Hi Cliffo

Why don't you heat up some of the wort you have just run off to sparge temp (77 degrees) and use that as your sparge water? You'll then be able to do more sparging without increasing your boil volume. Efficiency will go up.

There's a technical term for this technique but it escapes me atm.

 

[rwh]

decoction?

 

[Insight]

decoction?

Not quite. Decoction is boiling a portion of the mash and then adding it back to the main mash to acheive a higher "step" temp. I'll think of it, probably when I'm drinking tonight!

 

[cliffo]

Whoa!! thanks for all the input guys. Plenty of info for me to ponder.

Might have to look at finding the space/equipment to do a full boil.

Still, nothing wrong taste-wise with my current AG brews, just a bit shy on the alcohol % from what I was expecting (currently drinking a 3.8% American Amber Ale that tastes beautiful).

cliffo

 

[mika]

I've got a 50L mashtun, 50L kettle, generally do ~24L batch (post boil size in the kettle), sparge in one hit. Stable 60% efficiency. Where I get my grain crushed the owner of the HBS gets ~80% efficiency and I've seen them run the grain thru twice when I've been there.
Got me stuffed, but at least it's stable. Account for it in ProMash and life is good....start to run out of room in the Mash Tun for all the sparge water on the bigger recipes though.

 

[Geoff-Donnellon]

Get another pot

I have always used 2 I currently use, 1 x 24 L and 1 X 19 (Big W style) but I started using 2 x 19 L puting the hops in the most concentrated pot.

 

[SJW]

If it gets too hard, it's pretty cheap to add an extra kg of grain, but long term it does get annoying spending more per batch. I'm happy with 87%, i got there from about 75% on my first AG's with some help by reducing my crush gap, adding salts to every batch and acidifying the strike water slightly with citric acid and sparging with slightly hotter water so i hit 75C sparge every time.

I'm a little interested in these "salts" that are being added. What are they ? where do they go? and what do they do? And whats the go with citric acid?

 

[mika]

He's basically setting the water up to be like the water where the beer was originally brewed. Over here you can go to the Water Corp website and download the water quality report for the last 12months. Check your area and work out where the acid levels and carbonate levels are at. Over here in Perth with have slightly alkaline water, so a little citric acid buffers the water and gets the PH close to the 5.2 it should ideally be at. The carbonate levels (salt) have an affect on how strong the hops or malt come thru.