mash efficency and O.gravity

Brewing processes and methods. How to brew using extract, partial or all-grain. Tips and tricks.

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johnnynothumb
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mash efficency and O.gravity

Post by johnnynothumb »

I mash in a 10 gallon water cooler w 3 inchs of bottom space and have tried single infusion@155 (1 1/2 hrs.)
And step mashing with temps @120(30 min) 144(30 min) 155(60min) and sparge @170 over 35-45 min
I will draw off 6.5 - 7 Gallons of wort and reduce that to 5.5 -6gal. over
1 1/2 hrs. if the recipe calcs out at 1.091 I will get 1.070 it will typ. yield low on the gravity spectrum for any particular recipe
how can I improve my Og.
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Efficiency

Post by slothrob »

It sounds like you're fly sparging, so flow rate and manifold design are important, and I'm not really experienced with those things, but John Palmer seems to have it pretty well figured out in How to Brew. One way to test if this is the source of your problem is to try a Batch Sparge. If your efficiency goes up with a Batch Sparge, then you need to work out the tun design and fly sparge technique.

The biggest factor affecting efficiency is crush. Try closing your gap a fraction or having your shop crush your grain twice. If your efficiency goes up, without causing a stuck mash, try closing it a bit more, etc.

The other factor is the dead space at the bottom of your tun. If the design allows a lot of wort to remain undrained from the bottom, your efficiency will suffer. I ended up redesigning my pick-up tube, using bendable soft copper, so that it went right to the bottom of the tun and left only 1 pint of liquid.

Lately I've been hitting 88% efficiency by Batch Sparging, and I'm starting to get a little worried that I've got it too high! :shock:
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RE: Efficiency

Post by wottaguy »

Timely topic as a friend of mine had this same probelm as well. He uses a 5 gallon round cooler outfitted with a braided SS hose on the bottom and also fly-sparges. He was getting 65% efficiency all the time. We took a step by step approach to solving the problem. We decided to grind the grains with a finer crush then mash a batch to compare the numbers. We got the same results 65% eff.
We then decided to swap out the short (9") SS braid and replace it with a longer one, and keep the same setting on the malt mill. We installed a much longer braid (36") coiled in the bottom, then mashed up another batch..same recipe..and much to our joy, we had obtained an efficiency of 82%! Needless to say, we had to dilute the wort to get it to our required OG range.
This result made both of us very happy, and Bob has been getting 82-85% efficiency ever since!

I just wanted to share this information with the collective.

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Re: RE: Efficiency

Post by billvelek »

wottaguy wrote:snip ... We then decided to swap out the short (9") SS braid and replace it with a longer one, and keep the same setting on the malt mill. We installed a much longer braid (36") coiled in the bottom, then mashed up another batch..same recipe..and much to our joy, we had obtained an efficiency of 82%! ... snip
You need to have the right equipment configuration for the type of sparging that you do. If you are going to 'fly' sparge, then your manifold needs to be carefully layed out to minimize channeling; channeling is where a disproportionate amount of your sparge water flows through the same grains, effectively washing all of the sugar from them, but NOT flowing sufficiently through most of your other grains, and therefore leaving sugar behind. If you wish to continue to fly sparge, then you need to study a bit more about manifold design -- which typically does NOT include the use of a flexible bazooko (mesh hose) because they are somewhat randomly positioned and are not in the same configuration for each batch. More typical for fly sparging is either a false bottom or a "manifold" constructed of rigid tubing which is designed so that tubes are spaced to maximize uniform filtration and minimize channeling -- which is precisely what you experienced and are still experiencing -- at least to _some_ degree -- even with your extended bazooka. If you want to 'fly' spare, then I _think_ that John Palmer's book gives some advice, IIRC. 'Batch' sparging, on the other hand, is completely independent of how your equipment is designed because it does not rely on uniform dispersion of sparge water through your grain bed, but rather it depends upon widespread dissolving of the sugar in the sparge water by thorough stirring of the mash and sparge water, and after vorlauf, you are merely draining the wort. The advantage of fly sparging is that brewers can usually obtain a couple or _few_ percentage points more of extraction efficiency, but it takes longer and usually requires special equipment, in addition to the manifold, to unformly distribute the sparge water on top of the grain bed. It is also necessary to monitor progress because you generally need to keep the grain bed 'floating'. Batch sparging, on the other hand, which is what I do, usually sacrifices a small percentage of efficiency, and does require additional vorlauf, but ... on the whole ... it is easier and faster, in my opinion, and doesn't require special equipment or design considerations for the manifold.

Personally, I have a MONSTER 10' long stainless steel mesh hose, and my runnings drain almost like an open faucet, and I've never had a stuck sparge. I have even come around to the point that vorlauf is almost effortless. Here is my procedure.

1. After mash out, I put a bucket below my tun and just drain it ... period. Nothing that requires ANY more attention on my part.

2. After a couple of minutes, the tun is drained; I lay a very light plastic plate on top of the grain bed, and I slowly pour the bucket of runnings onto the plate, which breaks it's vertical force and keeps it from disrupting the grain bed and requiring further vorlauf. I will add that I am usually doing either a high gravity beer or a double or triple partigyle, so my grain bed is normally at least 6" or so thick. The downside that I've considered is the possibility that this causes hot side aeration, but I haven't noticed any problems with my beer. Either because of the mash out at about 170F, or the careful pouring to try to minimize areation, or else the short time before it is put into a kettle and brought to a boil (which drives the oxygen out), I just haven't had a detectable problem with HSA and therefore recommend my technique.

3. Because the grain bed has been set and isn't really disturbed (above), I then drain my first runnings without additional vorlauf.

4. I then add 1st sparge water all at once -- just dumping it into the tun -- and then I stir the hell out of it to try to get all those sugars to dissolve no matter where they are -- and then I rapidly drain into a second bucket (effectively this is my second 'automatic' vorlauf) ... to set the grain bed to filter for my second runnings. I then use the plastic plate again to 'break the fall' of the wort back into the tun. Then I just drain the second runnings into the bucket with no further vorlauf.

5. I then add 2nd sparge water as per step #4, above, draining it to reset the grain-bed filter ('auto vorlauf'), and then drain my third runnings into a third bucket. I then blend as needed for how ever many different styles I'm making (up to three for a triple partigyle).

Nothing can be simpler, and the entire process -- even for 10 or 15 gallons -- only takes about 20 minutes or so from mashout to starting the kettle. I can't even imagine waiting for a sparge to take 40 minutes or more. My efficiency is pretty consistent at about 80%, give or take a percent. I'll gladly pay an extra couple of percent for my grain to get the speed and ease that this method provides.

My equipment setup is to unplug the drain cap on my ice chest (which I also use to cool beer for parties), stuff a plastic hose through it and into the end of my 'bazooka' which is just randomly coiled in the ice chest, wrap teflon tape around the joint of the drain-plug 'pipe' and the tube I've inserted into it, and then elevate the tube by crimping it under the ice chest handle. NO drains, faucets, hose clamps, or anything else. Works great. To drain, I just lower the tube. "KISS" -- Keep It Simple, Stupid. :wink:

Cheers.

Bill Velek
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RE: mash efficency...

Post by wottaguy »

Nice method and post Bill! Thanks for sharing too.

That's the great thing about Homebrewing! There are many ways and methods to accomplish the desired results, and is probably the key to as why homebrewing is fun and always so interesting.

One can keep it simple..or one can tinker around and make their process more involved. I personally like to tinker with my system and try new methods, just to see the results. Sometimes it works out...and sometimes it's not so great, and I'll chalk it up as a learning experience.

I have changed by brewing set up at least 3 times this year alone and with each change I have noticed my brew day getting easier to manage, and real improvements to the finished product as well. At the same time, I am increasing the volume of beer I am able to produce in a single session, and I can now brew 25 gallons at a time. I also can brew up 5-10-15-and 20 gallons if desired (i have quite a few different sized brewpots!)..and will also be partigyling some sessions too.

I'm very happy with my set-up as well as you are with your's. I really don't worry about how long it takes to brew up a batch, as I totally enjoy focusing on the brewday experience and of hitting the numbers. To me, every brewday is special to me, and I'll always remember it.

Thanks again for your outstanding insights!

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johnnynothumb
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THANKS

Post by johnnynothumb »

YOU ALL HAVE GIVEN ME OPTIONS AND THINGS TO WORK ON. I HAD HOPED TO FIRE UP A NEW SYSTEM THIS WEEKEND BUT ITS IS RAINING LIKE HELL HERE AND IT WILL HAVE TO WAIT

THANKS AGAIN
ERIC LEDBETTER
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RE: THANKS

Post by wottaguy »

Eric,

I know what you mean about rainy days.

That's why I have configured my system to brew in the garage. It allows me to brew even on a mild rainy day. But id the weather is real bad, I'll wait until a nicer day arrives. I just very fortunate enough to have a garage to brew in.

Let us know how you make out on your efficiency issue and of any changes that you have made to improve it. I'm sure that there are others that would be interested in this topic.

Good Luck!

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