First AG: Horrible Efficency

[hoptopia]

Just brewed 2 all grain batches and both for some reason had a ridiculously low OG. My mash run temp was hard to control in a 10gallon rubber maid insulated cooler. The temp seemed to constantly drop below 150f, so I think I just didn't convert properly. I see all kinds of people using same system just fine.

I'm switching to a mash tun with a burner underneath so I can keep the temp consistent.

 

[boswell]

I haven't had any trouble, and I have the same cooler. I assume your hot liquor was hot enough? Or the cooler was cold. I fill mine with the hottest water from the tap to get started to preheat it. Im a total novice, but I don't think I lose more than a couple degrees over an hour.

 

[Dunerunner]

150 isn't that low, and both Beta and Alpha amalyse are active at that temperature. http://www.howtobrew.com/section3/chapter14-1.html What did your crush look like? Did you crush your own or did the LHBS do it for you?

 

[hoptopia]

Northern Brewer crushed it for me. I get my hlt to 165f, which ended up being about 155f, then kept cooling by 5f every 15mins. Maybe I should add hot water to mash tun and let it heat up before I mash in...my og was 1030!! Ridiculous

 

[copyright1997]

Just brewed 2 all grain batches and both for some reason had a ridiculously low OG. My mash run temp was hard to control in a 10gallon rubber maid insulated cooler. The temp seemed to constantly drop below 150f, so I think I just didn't convert properly. I see all kinds of people using same system just fine.

I'm switching to a mash tun with a burner underneath so I can keep the temp consistent.

What was your recipe's estimated OG and what was your efficiency (estimated and actual)?

One thing I will say is I just switched from a lhbs crush to one done with a barley crusher and my OG was through the roof due to a higher efficiency.

 

[hoptopia]

The second recipe estimated was 1047, and actual was like 1012!!

 

[emetcalf]

Northern Brewer crushed it for me. I get my hlt to 165f, which ended up being about 155f, then kept cooling by 5f every 15mins. Maybe I should add hot water to mash tun and let it heat up before I mash in...my og was 1030!! Ridiculous

5* every 15 minutes? Was your mash in a refrigerator with the lid off?!

Now that I got that out of the way, something is wrong with your mash. Even if you didn't pre-heat the tun at all it shouldn't lose much heat after the first 15 minutes. One easy way to pre-heat is to just heat your mash water 10-15* hotter than you want it to be (175ish in this case), then let the water heat up your mash tun and add your grain when it gets down to the temp you want (165). If you are still losing a lot of heat, then you have another problem somewhere else.

 

[jsled]

5* every 15 minutes? Was your mash in a refrigerator with the lid off?!

Indeed. I only lose 1-2°F over a 60 minute mash in a 50qt coleman cooler mash tun.

Now that I got that out of the way, something is wrong with your mash. Even if you didn't pre-heat the tun at all it shouldn't lose much heat after the first 15 minutes. One easy way to pre-heat is to just heat your mash water 10-15* hotter than you want it to be (175ish in this case), then let the water heat up your mash tun and add your grain when it gets down to the temp you want (165).

For me, it's basically 9°F exactly that I "lose" to heating the mash tun. So, a ~150 mash wants the water to be ~165, and so the water coming out of my HLT is ~174 … let it sit in the mash tun (lid closed) for a couple of minutes, and it comes out to ~165, then I add the grains and hit my mash temps pretty consistently.

 

[copyright1997]

The second recipe estimated was 1047, and actual was like 1012!!

1.012....wow. Something is *really* wrong. Maybe it would help others if you spell out your brewing notes in as much detail as possible, from the grain bill to your process to how you took measurements?

 

[Tall_Yotie]

Cooling of the mash does seem to be a big issue.

Are you stirring your grain really well at the sparge? Assuming you are batch sparging. This was my big issue when I got into AG, I was just not stirring enough, went from 55% to 75% efficiency.

Please do give some notes on your brewing process and your recipe.

 

[Primevci]

Cooling of the mash does seem to be a big issue.

Are you stirring your grain really well at the sparge? Assuming you are batch sparging. This was my big issue when I got into AG, I was just not stirring enough, went from 55% to 75% efficiency.

Please do give some notes on your brewing process and your recipe.

Do u stir with your sparge water are u doing batch I'm trying to figure out how to do this exactl

 

[Tall_Yotie]

Do u stir with your sparge water are u doing batch I'm trying to figure out how to do this exactl

I am batch sparging. I drain the first mash water, add the sparge water, and then mix the HELL out of the grain and water. Give it a minute to settle, and then vorlauf and drain. Repeat for the second sparge.

Just adding the sparge water and draining is not efficient. You have to stir it in like crazy. Spend at least an entire minute (time it) stirring the sparge water. Made a HUGE difference for me!

 

[bottlebomber]

Im not a huge fan of the NB crush, especially the last one they did for me (I had to run it through the food processor). But 1.012 is unheard of!

 

[Werbi]

Northern Brewer crushed it for me. I get my hlt to 165f, which ended up being about 155f, then kept cooling by 5f every 15mins. Maybe I should add hot water to mash tun and let it heat up before I mash in...my og was 1030!! Ridiculous

This sounds like a calculation or measurement issue. Either miss calculated the strike temp for the volume of water/grain (and the "drop" was just the temp equalizing at a point measurement -not stirred, taking temp in same place) or the measurements were bad. With the insulation of a cooler and thermal mass in a typical mash, `20º/hour sounds excessive (I only lose maybe 1-2º in a 90 min mash in an old-thin walled cooler! Did you use the same thermo for all measurements? Maybe one is way out of calibration? With measurements like that, I'd double check the equipment method of calculation first.

Good Luck.

 

[PurpleJeepXJ]

Figure out your cooling loss. Mine with the same cooler is 7f over 1hr and I mash for 1.75hrs. Longer mash times will help you make up for low efficiency.

 

[Jonas217]

The second recipe estimated was 1047, and actual was like 1012!!

It sounds like you were fly sparging and you drained the wort too fast. I did the same my first all grain batch. You need to adjust the rate of the wort coming out so it matches the rate of the sparge water going in. The level of the water in the mash cooler should remaim 2 inches or so above the grain bed. Both flow rates should be adjusted slow enough that the entire process takes between 45 to 60 minutes. If you drain the wort too fast not all of the sugar is washed from the grain.

 

[Yooper]

I don't think it's possible to get 1.012 out of a batch. I mean, even very low conversion would give you more than that.

Was the grain crushed at all?

I think there is a problem with your thermometer as well, as it's not possible to lose that much heat in the mashtun. No way.

Can you double check the thermometer?

 

[eltorrente]

First of all, I agree with the above post to check the thermometer. I can't understand how a mash could possibly come out at 1.012!!! that is just not right. A quality, calibrated thermometer is extremely important to every all-grain brewer!

I would invest in a digital thermometer (like 20bucks or so) that comes with a calibration certificate - OR, at a minimum, calibrate your existing thermometer with both ice water and boiling water.

Also, for reference, I have an Igloo 5 gallon cooler and it seems to drop less than 1 degree per hour.

 

[hoptopia]

I was not stirring the grain, I will do that on the next batch. My flow rate seemed to be pretty good, I kept the water about 2" above grain bed during sparge. Sparge water was 170f and I sparred for about 20mins. Maybe this was not long enough?

Also I thought 165f was too hot to mash In at? My target was 150f.

I was using a digital thermometer but I will calibrate it or get a new one.

As for my OG @1012, I have NO idea how that is possible.... My problem was with my OG already so god damn low I couldn't get up to my full volume. I was worried about dropping the OG down even further.

Maybe I need to start milling my own grain, or sparge for anlonger time?!?!

 

[JuanMoore]

Did you stir really really well to "dough in" at the very start of the mash? If not it might explain both the efficiency and weird temp readings to some extent.

I think there is a problem with your thermometer as well, as it's not possible to lose that much heat in the mashtun. No way.

True, but it can look like it if the grains never got doughed in, as they will continue sucking heat from the surrounding water throughout the rest.

Sparge water was 170f and I sparred for about 20mins. Maybe this was not long enough?

Also I thought 165f was too hot to mash In at? My target was 150f.

Sounds like you're fly sparging, in which case 20 min is way too short. You might consider batch sparging until you get the rest of your process down since it's a little more forgiving.

If the mash-tun wasn't pre-heated, 165F sounds too cold for strike water. The cooler and the grains are both going to suck up a lot of heat. How much depends on the weight and temp of both the grains and the mash tun.

 

[bottlebomber]

Nothing that's been said here even begins to explain why OP would have an OG of 1.012. I have richer wort than that draining from the MT when I finally get my preboil volume and shut it off. Im calling user error on this one. Bad hydrometer or something, maybe the paper scale slid down. You can mash some bread crusts and get better than 1.012

 

[Diesel48]

I recently got a batch of all grain from NB and the crush was not very good either. The OG was supposes to be 1.054 and I got 1.042. Used the LHBS mill for the next batch and all was well again.

 

[Accidic]

The first AG batch I did was in a bottling bucket and I didn't lose temperature that fast. The grain bed seems to hold a good bit of the heat even without consideration to the insulation so that does seem rather odd to me. It was a while before I was able to afford a cooler setup even but I did have some luck using a pair of heating pads I had and bungee cording them around the bucket which slowed the drop to only like 4 degrees with the lid on.

While it won't account for the entire thing did you temp correct for your gravity reading? I didn't quite understand that when I first started and thought I must be doing something wrong when I kept getting lower than expected results from Extract batches. There are a bunch of correcting apps or webpages out there. Here's one I've used:
http://www.brewheads.com/stats.php

 

[boswell]

I used my cooler today, only lost 4 degrees over an hour and a half, and that was only preheating with a gallon of strike water that was a little too hot, so I let it sit for 30 mins.

 

[prrriiide]

First things that come to my mind:

1. Faulty hydrometer - solution: go get some distilled water and check it. If it's bad go get a new one.
2. Faulty thermometer - same solution: check it in some boiling water and some ice water. If it's bad go get a new one.
3. un-heated tun - solution: heat your strike water over your dough-in temp. Let it sit in the tun until it cools down to strike temp.
4. Incomplete dough-in - solution: stir thoroughly as you ad the grain to the strike water. Add the grain slowly enough that you get a good mix.
5. strike water too cool - solution: pre-heat mash tun, and account for the grain temp

I really think it's 1 or 2 and a combination of the rest. I can't see that much/rapid temp loss happening with the thermal mass of the grain unless you leave the lid off and you're in Nome. But each variable brings a new set of problems, and they will compound each other.

But even with all of those things happening, 1.012 is just ridiculously low. That's why I'm leaning toward a bad thermometer anda bad hydrometer. Thermometers are relatively cheap, so I'd just go ahead and spend a few bucks more and get a good one. Also, look closely at your hydrometer...is there any liquid at all inside of it? I actually had a hydrometer that wasn't correctly sealed, and it developed some condensation on a cold day going from storage to wort. Moisture (even a thin condensation haze) in the hydrometer = added weight = low grav readings. The usual suspect is a slipped paper insert, so check for that as well.

But if we had vBookie on this site, that's where I would place my money.

 

[winvarin]

I know there is a lot of talk about cheap thermometers here, but (prepare for shameless endorsement of a product I have no vested interest, other than ownership of one, in) I would look into a Thermapen if you find that your thermometer is off.

1. It registers heat change FAST (I stabilize at temp usually in 2-5 seconds)
2. It takes a lot of splashing and still works
3. Long, stainless probe that can easily be sanitized with rubbing alcohol and a cotton ball if you need to take temp readings in cooled, post boiled wort.
4. Bobby Flay listed it as one of his "must have" grilling items
5. In addition to making great beer, since buying my Thermapen, my "medium" steaks are always "medium" and my wife's "medium-well" steaks are always "medium well", coming off the same grill!

 

[Accidic]

4. Bobby Flay listed it as one of his "must have" grilling items

You just had to go and ruin it for me with that part didn't you? God that guy bugs me.

 

[winvarin]

Bug you or not, the Thermapen is still awese

 

[Lemon]

My wild guess is the grain bill was a few pounds light. It could cause faster heat loss in the cooler, and would produce a low OG.

 

[MichaelBrock]

I'll add my .02 and follow up on what Accidic suggested. When I did my first all-grain batch I measured the sg pre-boil but did not cool my sample down to room temperature. Even using the temperature correction tables that purported to have the correction for 150 degree wort, the measurement was very low. After a bit of panic and further research I found out that the corrections for high-temperature hydrometer readings are fairly useless and that the wort should be cooled to near room temperature for any degree of accuracy.