Efficiency issues or am I doing something else wrong?

[wafox]

So I'm not sure what's up so I figured I would turn to you guys for some advice. The last 3 AG brew's I've done I've missed my gravity big time. I'm calculating my efficiency at 70%. But I'm hitting my target gravity far before I get the correct amount of wort out of my tun.

For example the recipe I'm did tonight - Pre-boil I should of been around 1.046 at 6 gals collected but I ended up pulling out 5 gals and the reading was 1.042

Same issues with the lager and the Irish red I brewed. Is this an efficiency issue or something else? I'm fly sparging nice and slow, my temps are right on. Any suggestions on how to improve my calculations? I'm using promash for my recipe building.

Thanks

 

[northernlad]

That last gallon should not pull your gravity up very much more. Consider tracking your efficiencies for a while to determine if you need to adjust your system number up.

 

[mlutha]

I just brewed a batch this weekend and my pre-boil measured 10 pts low. However, my post-boil 'recovered' back to where I was expecting. After some helpful responses on the board, I think I figured that my mistake was taking my pre-boil sample from the top of the kettle, without mixing it. I was likely sampling the last of the runnings, which were very weak, and the original heavier gravity runnings had settled to the bottom.

So, how are your post-boil gravity measurements - low as well?

 

[BrewBrain]

How many beers total have you done with your current system/setup? Your target efficiency should be what you typically really get - forget everything else.

I get between 65% - 68% brewhouse efficiency with most of my beers, so that's what I set up for. I wish it was better, but that's what I get. After you've done a few, you should know what efficiency you can expect. Set your software up for that and RDWHAHB. It's better to know what you will probably get and plan for it than to hope for better and miss.

That's not saying you can't try to increase efficiency, but make small changes, one at a time if you are tinkering with your process and/or setup.

 

[wafox]

My last brew was my 5th using this setup the first 2 game out perfect. The last 3 have all been low. I'm going to try a batch sparge on my next attempt and play for like 60% eff. see how it goes I guess.

the last 3 batches I just boiled longer to get my post boil gravity but I'm ending up with with 3.5 gallon batches due to evaperation so I gotta figure out what's up.

 

[BrewBrain]

Can you explain your setup? If fly sparging, is it possible you are getting channeling? If you get better efficiency batch sparging next time, I'd be willing to bet this is the case.

 

[wafox]

I'm using a 10gal rubbermaid rectangle cooler as my mash tun Using a ball valve and a hose braid to get the wort out - pretty standard home setup. I'm fly sparging from a siphon keeping about 2" or so of water above the gain bed.

What's "channeling"? Thanks for the advice and help - I'm going to see what happens using a batch sparge.

 

[ajf]

Channeling is caused by introducing the sparge water into the top of the MLT, and instead of it percolating evenly through the grain bed, it finds the easiest route to the outlet and drills "channels" through the grain on its way to the outlet.
This causes the grain in the vicinity of the channels to be over-sparged, and the grain not near the channels to be under-sparged.
To prevent channeling, you need a collection mechanism that collects the runnings across the whole of the base of the MLT, such as a false bottom.
A braid that meanders around the bottom of the MLT could work well, or a manifold with cross members would also work. A short, strait braid will only allow a very small collection area above the braid, which will result in the majority of the grains not being sparged, as most of the sparge water will find the easiest way to the outlet through "channels". The good news is that when batch sparging, channeling is not an issue. When batch sparging, the sugars are extracted while stirring after adding the sparge water, and everything that makes it's way to the outlet will have the same gravity.

-a.

 

[wafox]

ahh, ok I get it. the braid runs around the entire bottom of the cooler but I could see how that would be a big issue. Thanks for explain' it for me

 

[AiredAle]

+1 on ajf's answer.

Braid is best used for batch sparging, where all the liquid is drained out dry. A manifold that allows an even drainage of the mash tun will give better efficiencies by minimizing channeling during fly sparging.

See John Palmer's How To Brew chapter on mash tuns for a clear explanation of the flow patterns in mash tuns.

Repeat one of your low eff fly sparged recipes, but batch sparge it using the same amount of water and compare efficiencies. If the braid is causing channeling, this should show up as an increased efficiency in the batch sparged brew.

 

[portjeffbrew]

I have been getting about 82-86% efficiency fly sparging using a braid set-up in a Gott cooler with a make shift false bottom and a colander at the top to evenly distribute water. Make sure your water temp is correct and run your valve SLOW. It typically takes me almost an hour to run 5 gallons thru (20 minutes per gallon). When I rush the eff. always tanks.
PJB