Why low effeciency?

[Starrider]

THis is only my second all grain batch but in both cases my efficiency turned out lower than expected. There isn't much consistency between batches as the first one used a cooler tun and this batch was a biab.

The recipe is a hefeweizen or more accurately an American wheat since I used Us-05 yeast.
I have never made a wheat so I decided to do a half batch (2.5 gal). I watched temps pretty closely and added low heat a couple time to make sure it didn't drop off.
According to iBrewmaster, target OG was 1.048 bit it came in at only 1.042. Brewmaster calculates that at only 58%. It should be fine except for lower ABV but I'm also afraid of lost flavor or body.

If anyone has any ideas or words of wisdom, I would appreciate it.

Recipe:
2.5# wheat malt
2# 2-row
0.5# cara-pils/dextrin
0.5 oz. Hallertauer
US-05 yeast

Mash steps:
Protein rest - 14 qts water 129 deg for 30 min
Beta saccharin rest, heat to 148 deg, hold 20 min
Full body infusion, heat to 156 deg hold 45 min

Iodine test showed full conversion.

 

[shoreman]

I would just say that maybe on you next batch try a simple batch sparge or BIAB and try to hold temps for 156 degrees for an hour.

The multiple steps with all the rests may have had an impact on your efficiency.

I Luke to keep it as simple as possible with this hobby.

 

[atoughram]

My efficiencies on wheat beers have been from 61 to 65% whereas my all barley malt beers are 75 to 80%. The only answer I have is that wheat is smaller and needs to be milled tighter than barley. Now that I know that the best I'll get is 65%, I'll adjust my grain bill accordingly. (I mashed the wheat beer at 148f for an hour and got full conversion)

 

[KeystoneHomebrew]

atoughram is onto a good point. Most barley mills will handle wheat no problem, but some have trouble getting a good grind. It is never a bad idea to get your wheat double ground. Another issue is that wheat does not have a husk, causing it to thicken the mash. Whenever approaching 30% wheat (20% BIAB in my opinion), getting some rice hulls in there will ensure a good flow and rinse of the grain. Usually one pound of husks is plenty.

Your temperature rests look nice, but were probably unwarranted. Unless the malt you used came with a fancy name like "Bohemian" or the like, it was modified malt. Meaning that the old world ways of step mashing are only adding time to the process, and not fermentable sugars. It is also possible while raising the temp to go overboard and hurt a portion of the grain's conversion. For the next batch, try a single infusion and see if that helps.

 

[C-Rider]

Yea, I was wondering a bout the lack of rice hulls myself.

 

[Starrider]

Wow, thank you all for the quick responses.
A couple points I left out of my process; I did do a batch sparge/rinse with 2 quarts of 170 deg water. Boil time was 90 min, not that that has an impact on this conversation.

I'm glad to hear that the multiple steps are really not necessary. It really added a lot of time to the process.

I missed the rice hulls. Other recipes I looked at for examples didn't have them either. I will definitely add them to the recipe. The pound of rice hulls you mentioned, is that for a normal 5 gal batch or for the 2.5 gal batch here?
I did stir the grains several times during the process just to make sure they didn't pack down. Not sure if that was a good idea or not. I don't see a lot of reference to stirring during the mashing process on the net.

I was a little paranoid about temperature. When raising, I stirred frequently to make sure I didn't overshoot. I have some trust issues with my thermometers so I was actually using four of them at one point. I have 2 digital kitchen meat thermometers that I thought would work fine for this as well but not sure they were reading correctly below 170 degrees. I also used the dial thermometer that came with my turkey fryer and my digital multimeter that has a temperature probe. The multimeter and dial had matching readings but the meat thermometers were both reading about 20 degrees high and didn't match each other. They went right back in the drawer.

Thanks again for everyones help. One last question, what should the the iodine test look like at full conversion? This was the first time I used the test so not sure I understand it correctly. It came out a very light brown or even tan. My understanding was that as long as it wasn't still black or blue that conversion was complete.

 

[C-Rider]

I missed the rice hulls. Other recipes I looked at for examples didn't have them either. I will definitely add them to the recipe. The pound of rice hulls you mentioned, is that for a normal 5 gal batch or for the 2.5 gal batch here?.

You won't see rice hulls in many all barley recipes. Usually in those w/wheat and rye both of which can from dough balls and low eff.

 

[beerandloathinginaustin]

I was a little paranoid about temperature. When raising, I stirred frequently to make sure I didn't overshoot. I have some trust issues with my thermometers so I was actually using four of them at one point. I have 2 digital kitchen meat thermometers that I thought would work fine for this as well but not sure they were reading correctly below 170 degrees. I also used the dial thermometer that came with my turkey fryer and my digital multimeter that has a temperature probe. The multimeter and dial had matching readings but the meat thermometers were both reading about 20 degrees high and didn't match each other. They went right back in the drawer.

Get a thermapen. It's one of my favorite brewing toys.

 

[KeystoneHomebrew]

Stirring the mash never hurts anything. Just make sure you're not driving off heat while doing it. Usually after the initial stir, a quick swirl the last 15 minutes is all you need.

Usually 1 pound of rice hulls is good for 5 gallons, or a 10-12 pound grain bill. Just chop it in half if you have a smaller grain bill.

If brewing all-grain, your thermometer is just as important as your pot and burner. That's one piece of equipment you don't want to skimp on.

And lastly, and this is only my opinion, skip the iodine test. Unless you have some really, really, really wacky water or boil your mash, you're going to get full conversion. That's one of the upsides to most malt being modified these days. I've never seen a brewery do an iodine test.

 

[cyclonite]

+1 on a good thermometer, and I also recommend the thermapen.

NOTE: You don't need rice hulls if you are BIAB mashing - they are used to prevent a stuck mash in a mash tun, and serve no purpose in BIAB (never a stuck mash).

I agree on skipping the iodine test also, unless you are using a high amount of raw adjuncts (e.g. raw wheat, raw barley, oats, etc).

 

[sikkingj]

As many of the posts allude to but don't explicating address - it's all about the crush (grain crush). If doing BIAB pulverize your grains and bask in over shooting your OG. If you are a traditional grain brewer. - change over.

If traditional, adjust he crush (finer or double milled), stir like crazy and use 1 pd. of rice hulls.

Best of luck.


PS
Your not that far off from your OG - run with it and see where it goes. Then follow-up and let us know what happened.

 

[Starrider]

Thanks all for the updates. I will definitely invest in a decent thermometer.

I am glad to hear the iodine test is not necessary any more. I was afraid that my low efficiency was from not reaching conversion but as you noted and the test confirms, I am getting full conversion.


I use the mill at the HBS and I don't think it is adjustable, at least not by me. Sounds like running it through twice will help though.

When I up the Hef to a full batch, I will definitely add the rice hulls. Full batch will be back in the tun.
I will say that I was pleasantly surprised at how this first BAIB batch went. Clean up was much easier that washing out the tun anyway. Washing out the tun in the winter could be tricky. Rinsing out the bag was a breeze. I don't think I will be making many half batches though.

I love this forum and getting all the input and information from all you more experienced brewers. Thanks for all your help.

 

[jason91notch]

I thought the sole purpose of rice hulls was to help prevent stuck sparges in a mash tun? Am I wrong?

Reason I ask is the last two batches I have done have had poor efficiency, (.008 off of target) but have been roughly 25% wheat. How would have rice hulls helped?

 

[sikkingj]

I thought the sole purpose of rice hulls was to help prevent stuck sparges in a mash tun? Am I wrong?

Reason I ask is the last two batches I have done have had poor efficiency, (.008 off of target) but have been roughly 25% wheat. How would have rice hulls helped?

Rice hulls only help with stuck spares - if BIAB then you don't need them.

As for the low efficiency, adjust the crush, hat helped me get closer to my target SG.

 

[JDGator]

Also make sure your volumes are correct.

 

[Catawampus]

I BIAB and almost always get slightly lower mash efficiency with significant portions of wheat. I tend to get anywhere from 68% (for 100% wheat mash) up to about 74% for mixes. I don't really see where the step infusions would have lowered your efficiency. I get up toward the higher end by actually crushing the wheat 3 times. Its smaller than barley so you really need to pulverize it. (Really, the same applies anytime in BIAB.) Poor crush, I would say, is by far the most plausible reason for being off. However, you are not terribly off. I think it will be a great brew if all else goes well.

 

[RM-MN]

I use a Corona style mill and get very good efficiency with wheat or barley. Yes it is all about the crush/grind. Wheat is smaller and harder than barley so any crusher type mill will have problems with it. Getting it crushed at your LHBS will not get you the highest efficiency because of this. If you must have it crushed and own your own mill, condition the wheat by wetting it for a time prior to crushing as this will soften and swell the kernels so they crush easier and more fully.

You won't need any rice hulls. Your BIAB bag is your filter medium and you can use pressure (called squeezing) to force the wort out. You also don't need to do a mash out nor do you need hot water for a sparge. You actually gain very little by using hot water as the grains will be hot enough to heat up your sparge water anyway. Since you will be pulling the grains out of the pot and begin heating the collected wort, that equates to the mashout of the fly sparging people.

 

[Starrider]

Hopefully one day, I will be able to remember all these tidbits. This is great information but if I don't write it down in my batch notes, good luck.

I cracked the first bottle of this batch a couple days ago and I think it turned out quite well despite the low efficiency. The next batch will be 5gal so I will likely be using the tun.


Since then I have made another batch of Irish Red which is mostly 2-row. On suggestion, I ran the grains through the LHBS mill twice. I also talked to them about their mill and they said they had recently adjusted the grind.
My efficiency came up but still about 67%~68%.

Can you over crush?

Getting my own mill will be down the road. Would like to upgrade my boil kettle (still using turkey fryer pot) and start collecting some kegging equipment. Have to appease SWMBO after all.

 

[RM-MN]

Can you over crush?

Yes, even doing BIAB you can over crush, but you have to have the malted grain looking like flour to do so. If the particles are fine enough to go through the weave of the bag, you've over crushed. We're really talking about flour to do that though.

 

[LovesIPA]

I'm still not sure if you're using a mash tun or BIAB. I use a tun, so I'll talk about that.

You can over crush, but that's not necessarily a bad thing because if you use rice hulls it doesn't matter how fine the grain is. You can crush really fine and use rice hulls on every batch and you will get good efficiency. I have my mill set pretty tight (no feeler gauge though) and the last batch I brewed yesterday I got 90.24%. I had 8.5 lbs of 2-row and 1.625 lbs of wheat. I didn't use any rice hulls either, mostly because I wanted to see if it was going to stick. I had rice hulls on hand in case it did stick but I had no problems.

edit: I used a credit card to set my mill. According to some google searches, a credit card is about .030 thick so that's pretty close to what my mill is set to.

 

[sikkingj]

RM-MN is correct if you crush to the point hat it passes through your bag, you will have cloudy, but incredibly potent beer ( on account of the high efficacy). So from my perspective you cannot over crush your grain - meaning doing so will not prevent you from brewing, just that what you brew may not be picture perfect.

 

[Starrider]

I’m glad to hear that. Thanks for all the feedback.
94%????? WOW!
I have no idea what the LHBS has their mill set at but it can’t be too tight.

This wheat batch was a BAIB. I had never brewed wheat before so I did a small batch on the stove. I use a homemade cooler tun for the 5 gallon batches. I will be running future batches through the mill at least twice if not more.
I brewed a batch of Irish Red about a week and a half ago and running the grains through the mill twice got me about 67%. The grain bill was calculated using a lower efficiency so ABV will be a little higher but only about 5.5%

You have me looking at corona mills now too if for no other reason than I could control my crush better. I wish my SWMBO drank beer. Acquiring new equipment wouldn’t be such a hassle. All she sees is the expense of grains and equipment, not the savings of not buying beer from the store. It doesn’t help my cause any that I only used to buy the cheap *%$# so the savings doesn’t completely cover the costs. How many hobbies have any payback at all?

To her, “beer” is a 4 letter word. Damn, it is a 4 letter word.

 

[Milan37]

Keep in mind that higher efficiency isn't necessarily 'better'--what's important is finding a technique that gives you consistent results. So I think it's important to keep good notes.

I'm going through that now with trying different crushes. I mentioned on another thread that I double-crushed two batches ago and got 81%. Most recent batch I triple-crushed (really fine flour) and got 91%. So the question before me: is that bump in efficiency worth the extra crush? Right now I'm thinking not--I'm going to work to dial my system into ~80% every time and run with it.

The most recent batch is still conditioning so I'm not sure if I'll see clarity issues or not. I prefer my beer to be clear (within reason) so if it seems to turn out cloudy that's an argument (for me) against really fine crush.

 

[Catawampus]

Keep in mind that higher efficiency isn't necessarily 'better'...

+1

Milan37 brings up a really good point in all these types of efficiency discussions. High efficiency is not always better. Your efficiency is good whenever you're making the beer you're targeting and it tastes the way you want.

My efficiency for a long time was consistently around 78-82% (and note this was with no-sparge, no mash-out, and full volume mash--I wasn't even squeezing the bag that well). Yet, I deliberately adjusted my process to get down around 72-75%. I just had the impression that my beers were a little too crisp, thin (in a harsh way). I tried adjusting water, carbonation, hopping schedules, etc., but finally dialed my efficiency down a little. I can't speak for others or their systems, but I like my beers better at a little lower efficiency.

 

[tennesseean_87]

Wheat beer has given me eff trouble, too. The last batch I used it in, (~30%) I crushed all my grain in my Corona, then gave her another 1.4 turn for the wheat, then returned it for the next batch. I hit my standard eff, so no troubles with that one!

 

[Starrider]

I understand what you are saying about too high. Wheat beer aside, the highest effeciency I have achieved so far is about 67%. Not aweful but would like to get it into the mid 70's. I think I could be happy there too.
I agree that being consistent would be the key.

I thought I read somewhere that you werent supposed to squeeze the bag?
If you are (can), should you also compress or squeeze the grains in the tun as well?

 

[JDGator]

squeeze the bag as much as you can to get the last few drops out. that is not a problem. i have a clean BBQ grate i use and place it over my pot. then i use the lid to push down on it and then let it drip until almost at a boil.

 

[RM-MN]

I understand what you are saying about too high. Wheat beer aside, the highest effeciency I have achieved so far is about 67%. Not aweful but would like to get it into the mid 70's. I think I could be happy there too.
I agree that being consistent would be the key.

I thought I read somewhere that you werent supposed to squeeze the bag?
If you are (can), should you also compress or squeeze the grains in the tun as well?

I though I read somewhere that you weren't supposed to eat potatoes, white rice, red meat, drink alcoholic beverages....

You can't squeeze the bag too hard, you aren't strong enough.