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bairdo 04-28-2014 12:18 AM

Why is my efficiency so low?
 
My latest brew (my 3rd brew ever) only yielded 53% (brewers friend) efficiency which I feel is low considering my brewing system. When I say low I'm referring to the OG. OG for the lastest brew was .050, at 65% I'd be hitting .061.

I have 3 keg system. Mashtun has a pico false bottom (homebrewing.org) I lowered it so there is now 5 liters below the FB (instead of 9.5). I have a march pump for circulating. Pic of FB here

lowered false bottom



Here is my process for a 23L batch. Can anyone see anything glaringly wrong with what I'm doing?

1. Boil 10L in mashtun to sterilize and heat it up a bit (maybe boiling some of the sparge water is a bad idea?)
2. Add 12L more of cold water to mashtun
3. Heat the 22L in mashtun to 72celcius (Circulate with pump till temp is stable)
4. Add the grains (6.8kg for the last brew) and stir for 5-10 mins till I can't see any more clumps. I also have the pump running on low during this step.
5. Stop stirring / switch pump off, put lid on and wait for 60mins. (temp is now 66-67)
6. After 60 mins switch on the pump on low for 3-5 mins to in theory clarify the wort.
7. Begin fly sparge (sparge water heated to 67). Sparge water is introduced to top of mash onto a small round plate (to avoid blasting a hole in the grain bed). The wort is pumped into the boiler at about the same flow as sparge water (medium to slow speed - not sure how fast or slow I should be going?) Pic of sparge arm here

Sparge arm


8. Stop lautering when the boiller has 28.5 litres in it - I know I should test the wort gravity to decide when to stop lautering but thats a pain in the arse to do.

BTW attenuation is good, 82% for the last brew. Fermentation occurs in a temp controlled fridge with heat pad.

Any thoughts will be appreciated. Thanks!

bairdo 04-28-2014 07:11 PM

Anyone..?

CA_Mouse 04-28-2014 07:28 PM

Without checking your pre-boil wort gravity, you cant tell where the issue is. Boiling longer can raise your gravity (as I'm sure you know). Over sparging and collecting too much wort will dilute your wort and can cause a low gravity as well. If you are sure you are collecting the right amount of wort and have your boil-off factored correctly, then you need to look into your grist bill. It does sound like you are getting a bad gravity from the start though. I can get the same SG from my 12# grist every time I brew it. I mash in a converted cooler without a constant fire until it, so there are most likely a lot of differences between your method and mine.

uatuba 04-28-2014 07:29 PM

First, why are you sanitizing your mash tun? Don't boil anything prior to your final wort collection,

Instead of dissecting your process, let me walk you through mine. I usually hit ~85%. I only have a two-tier system. My grain is crushed at .039 if I am using carapils and .038 if not.

1) Add 2 gallons of treated water at 10* F higher than desired mash temperature in the mash tun and seal the lid.

2) Continue heating the remaining volume of water to the strike temperature. I determine the strike temperature based on the temperature of the grain, the amount of grain, and the desired mash temperature. There are plenty of calculators online to help you determine strike water volume and temperature.

3) Add water first, then dough in and stir with mash paddle, but not excessively.

4) Seal the lid and wait for 60 minutes. I do check the temperature after 10 minutes.

5) Calculate sparge water temperature and volume so that the grain temperature will be raised to 171* F. Again...online calculators.

I batch sparge, so fly sparging will be slightly different. The important thing is that you raise the grain temperature to 171* so that enzymes are denatured.

Now, if you our thermometer is not accurate, you're screwed. I hit 80% with my first AG batch and would have hit higher had I filled my mash tun lid with spray foam. After I did that, I'm able to hold the temp for an hour. Check you thermometer, quit heating your water too high (boiling), and RDWHAHB.


Sent from my iPad using Home Brew

eric19312 04-28-2014 07:46 PM

You have nice gear. Much nicer than mine. Cough up $30 for a refractometer so you can check gravity on the fly. No excuse to not have preboil gravity.

SudsyPaul 04-28-2014 08:04 PM

Definitely echoing some of what was said... Get a refractometer.
If you have a HERMS setup, then make sure you're taking measurements all over the place.

When you say your sparge is medium to slow... it should be slow to "is there anything even coming out?". You want the sparging process to take about 40-45min. Fly sparging is less work than batch sparging, but it's really the same amount of time.
When fly sparging, your arm should be well above the wort level, and the wort should be 1-2" over your grain bed. Based on your pic, your sparge arm is too low, which means your wort is too low, so maybe you're getting channeling through the grain bed or something.

bairdo 04-28-2014 08:09 PM

Quote:

Originally Posted by uatuba (Post 6094055)
First, why are you sanitizing your mash tun? Don't boil anything prior to your final wort collection,

Instead of dissecting your process, let me walk you through mine. I usually hit ~85%. I only have a two-tier system. My grain is crushed at .039 if I am using carapils and .038 if not.

1) Add 2 gallons of treated water at 10* F higher than desired mash temperature in the mash tun and seal the lid.

2) Continue heating the remaining volume of water to the strike temperature. I determine the strike temperature based on the temperature of the grain, the amount of grain, and the desired mash temperature. There are plenty of calculators online to help you determine strike water volume and temperature.

3) Add water first, then dough in and stir with mash paddle, but not excessively.

4) Seal the lid and wait for 60 minutes. I do check the temperature after 10 minutes.

5) Calculate sparge water temperature and volume so that the grain temperature will be raised to 171* F. Again...online calculators.

I batch sparge, so fly sparging will be slightly different. The important thing is that you raise the grain temperature to 171* so that enzymes are denatured.

Now, if you our thermometer is not accurate, you're screwed. I hit 80% with my first AG batch and would have hit higher had I filled my mash tun lid with spray foam. After I did that, I'm able to hold the temp for an hour. Check you thermometer, quit heating your water too high (boiling), and RDWHAHB.


Sent from my iPad using Home Brew

I said why I boil the first 10L of mash water - to sterilize (ie. starting with clean equipment) and as a bonus it pre-heats the mashtun. The when I add 12L of cold water I still need to heat the now 22L up to the desired strike temp (I don't see why that's a problem unless boiling the water does something undesirable to it?)

My sparge water temp could be higher but that won't be effecting efficiency - or will it?

I don't know the mill size but it gets milled at the most popular home brew supplier in Auckland - they definitely know what they're doing (unlike myself) so unlikely to be a problem there, but I will ask them next time I get grains.

Why is sealing the lid important? over the hour my mash will drop up to 1.5deg (eg. from 67 to 65.5). I thought that wasn't a bad thing?

My strike temp is spot on so no need to change anything there.

uatuba 04-28-2014 08:13 PM

Quote:

Originally Posted by bairdo (Post 6094148)
I said why I boil the first 10L of mash water - to sterilize (ie. starting with clean equipment) and as a bonus it pre-heats the mashtun. The when I add 12L of cold water I still need to heat the now 22L up to the desired strike temp (I don't see why that's a problem unless boiling the water does something undesirable to it?)



My sparge water temp could be higher but that won't be effecting efficiency - or will it?



I don't know the mill size but it gets milled at the most popular home brew supplier in Auckland - they definitely know what they're doing (unlike myself) so unlikely to be a problem there, but I will ask them next time I get grains.



Why is sealing the lid important? over the hour my mash will drop up to 1.5deg (eg. from 67 to 65.5). I thought that wasn't a bad thing?



My strike temp is spot on so need to change anything there.


You aren't sterilizing anything unless you have a huge ass autoclave. The point is that nothing preboil needs to be sanitized. My issue with the boiling is that you may be using way too much heat in your mash, which will denature enzymes early, and which will result in poor efficiency.


Sent from my iPad using Home Brew

SudsyPaul 04-28-2014 08:21 PM

Also.. you're wasting energy and water :p

But if your sparge temps are too low, you'll definitely lose efficiency. Sparge water needs to be hotter (to get grains to 168-169f) in order to liquify the sugars and extract every last bit of sugar for your wort. If you're not doing that, then your efficiency is going to take a hit.

bairdo 04-28-2014 08:25 PM

Quote:

Originally Posted by SudsyPaul (Post 6094136)
Definitely echoing some of what was said... Get a refractometer.
If you have a HERMS setup, then make sure you're taking measurements all over the place.

When you say your sparge is medium to slow... it should be slow to "is there anything even coming out?". You want the sparging process to take about 40-45min. Fly sparging is less work than batch sparging, but it's really the same amount of time.
When fly sparging, your arm should be well above the wort level, and the wort should be 1-2" over your grain bed. Based on your pic, your sparge arm is too low, which means your wort is too low, so maybe you're getting channeling through the grain bed or something.

I don't have a herms setup.

Right.. ok so I'm almost certainly sparging way too quickly. Didn't time it but pretty sure it only took 10-15mins. The sparge arm sits just below the water line and the reason I decided not to have it above the water line is apparently aerating hot wort is bad (according to section 3 'how to brew' "One advantage to using a manifold, versus pouring the mash into a strainer, is that you avoid aerating the wort while it is hot. As was discussed in Chapter 6 Yeast, and Chapter 8 Fermentation, oxidation of hot wort at any time will lead to flavor stability problems in the beer later"). And I've seen a bunch of systems where the sparge arm/arms sit on the grain bed.

As far as measuring here there and everywhere, I've already spent too much on the system and should be able to get some decent beer out of it. Given my lack of experience its far more likely to be a procedural problem than a lack of measuring. I will eventually get a refractometer, I understand its purpose but you don't need one of those to make good beer (I know people making beer in chilli-bins (coolers) who are getting way better efficiency than me)

Thanks muchly!


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