Insanely Low OG

[TheGreatRoad]

Hopefully you guys can help. I've been having terrible OG readings for a few batches now ever since I switched from BIAB to converting a 10G igloo into a mash tun. I have to be doing something wrong but I can't seem to figure it out. My breaking point came today when I brewed what was supposed to be an IIPA at 1.085, but my OG reading came out at 1.043.

After my last batch (est 1.057 measured @1.040) I finally calibrated my thermometer, which was about 10-12* off. I had high hopes that would turn things around, but apparently that wasn't the only issue.

Other than that the only thing I can really think of is that my water calculations are off. I generally depend on Beersmith to calculate all that for me, but I should probably start doing my own since I end up with too much. I'm starting to think my gravity points are going down the drain. I'm already keeping as much as my boil pot can handle.

My sister comes in from San Diego next month and I need to get my numbers back up for the IPA I plan on brewing for her. I'd hate for it to turn out to be a blond in the end. She has high standards having lived in SD for so long.

Thanks guys.

 

[lolcats]

Hey,

What's your recipe? How much grains quarts/lbs?
What was your pre boil gravity? Did you measure it?

 

[RM-MN]

Do you run of the first runnings, then batch sparge and get a low OG? If so you have the same problem as many extract brewers, you first runnings are dense and stay in the bottom while you add low density second runnings. If you take your sample off near the top, you are getting just the second runnings OG. Even stirring may not get them to mix properly.

 

[max384]

Do you mill your own grains?

 

[chickypad]

Yep need more info, like actual volumes including all losses, process for sparging, grainbill. RM-MN has a very good thought, compared to full volume mashing you really need to mix late runnings in well to get an accurate OG - IME a lot more mixing than you might think. I will often stir a number of times as it's heating then take the OG sample just after it starts to boil. Also you are right you shouldn't rely on Beersmith to tell you anything, rahter you need to tell it about your system.

 

[masamunexc]

I used to make the mistake of adding my grains to the mash tun before the water, ended up being way too hot and I think it destroyed the enzymes needed for starch to sugar conversion. The beer had a very low OG but still turned out ok, i learned to add the water first, let the temp stabilize, check it then add the grains when I was satisfied. So take a look to make sure your strike water isn't too hot for starters.

Edit: just read that you checked your temps, nvm

 

[TAK]

A few things to consider, in addition to what's already been said...

- Are you taking a hydrometer reading hot?
- Have you checked the calibration of your hydrometer, i.e. are you sure it didn't get messed up and is giving bad readings?
- You just switched from BIAB to a cooler MT, any chance you're not mixing well enough and leave dough balls in the mash?

 

[TheGreatRoad]

Hey,

What's your recipe? How much grains quarts/lbs?
What was your pre boil gravity? Did you measure it?

The grain bill is pretty simple. See below.

7 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 82.7 %
1 lbs Vienna Malt (3.5 SRM) Grain 2 11.0 %
8.0 oz Cara-Pils/Dextrine (2.0 SRM) Grain 3 5.5 %
1.0 oz Chocolate Malt (350.0 SRM) Grain 4 0.7 %

Grain/water = 1.25G

Taking preboil gravity readings isn't a step I've routinely done. In this instance, I did not. Sorry.

 

[TheGreatRoad]

Do you mill your own grains?

No, I get all of my grains from morebeer.com

 

[TheGreatRoad]

Now that I'm a few hours removed from the staggering readings, I went back and checked some notes and realized that my batch sparging process has been off the last couple batches. I don't think that completely solves the problem, but it's a start.

Instead of draining the mash tun then adding the sparge water, stir, then drain again...which I did the first two batches with the new setup, I just added the sparge water right into the MT, stirred it up and then drained it all. In an effort to reduce the number of pots I had out, I just used my boil pot as my HLT at that time and didn't think about the impact of what I was doing. I needed that second pot.

I don't think that's the entire solution, but its a big step towards it....hopefully.

Thanks!

 

[lolcats]

Grain/water = 1.25G

1.25 lbs per gallon? that would be very low!

 

[specharka]

1) Use a properly calibrated hydrometer and thermometer for all your brewing needs. Replacements aren't expensive.

2) It helps to have an index as to when this is occurring. Take hydrometer readings of your first runnings, and intermittently through the sparge to make sure that the adjusted runoff gravity never goes below 1.015. And always take a pre-boil gravity reading so you can hit that desired O.G. every single time.

3) Consider upgrading to a fly sparge versus a batch sparge. I saw an increase in efficiency from 60 - 80%, with an additional investment of about $55. If your mash kettle has a bulkhead valve and/or thermometer, you can kill 2 birds with one stone.

4) Collect as much wort as your kettle will allow and use an extended boil, if necessary, to make up the difference. If you're using less than a ten gallon kettle for a full volume boil, consider an upgrade.

 

[theseeker4]

Now that I'm a few hours removed from the staggering readings, I went back and checked some notes and realized that my batch sparging process has been off the last couple batches. I don't think that completely solves the problem, but it's a start.

Instead of draining the mash tun then adding the sparge water, stir, then drain again...which I did the first two batches with the new setup, I just added the sparge water right into the MT, stirred it up and then drained it all. In an effort to reduce the number of pots I had out, I just used my boil pot as my HLT at that time and didn't think about the impact of what I was doing. I needed that second pot.

I don't think that's the entire solution, but its a big step towards it....hopefully.

Thanks!

How much water was left in the mash tun when you were done draining? That definitely hurt your OG numbers, and if there was a large amount of wort left, probably could account for all the sugar deficit.

 

[max384]

No, I get all of my grains from morebeer.com

The vast majority of poor efficiency problems (and this is an efficiency problem, not a low OG problem) encountered here stem from poor grain crush. A $25 corona mill, once properly adjusted, will give you far better efficiency and decreased variability than store-milled grain will. You don't know what their crush is set to, and you don't know if they recently adjusted their crush, leaving you at the mercy of their milling process. This is where I would start. My efficiency went WAY up once I invested in a cheap corona mill. Several years later I still have that same el-cheapo mill, only I power it by drill, rather than hand... Which was a $0.50 and five minute upgrade.... Well worth it.

 

[catdaddy66]

1.25 lbs per gallon? that would be very low!

All of my software recommends this ratio, though I use 1.35 lbs/gal in order to collect wort for future yeast starters. I do know a bit more volume will increase the efficiency especially in higher gravity beers (>1.060).

 

[wysiwyg]

I'm not sure how to get 1.085 from only 10 lbs of grain. Just a swag, but I'd think you'd need about 14 lbs to achieve that kind of OG. 10 lbs sounds like a 1.043 beer with average efficiency.

 

[Gavin C]

The grain bill is pretty simple. See below.

7 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 82.7 %
1 lbs Vienna Malt (3.5 SRM) Grain 2 11.0 %
8.0 oz Cara-Pils/Dextrine (2.0 SRM) Grain 3 5.5 %
1.0 oz Chocolate Malt (350.0 SRM) Grain 4 0.7 %

Grain/water = 1.25G

Taking preboil gravity readings isn't a step I've routinely done. In this instance, I did not. Sorry.

9lbs 1 oz grain bill

If your planned batch size is 5.5 gallons and your brewhouse efficiency is 80% that's going to get to about a 1.050 +/- a couple of points beer.

What's your batch size?
You should be taking a preboil reading if you want to know how effective your mashing process is. Not everyone cares. If you don't then don't bother with one.

Edit: @wysiwyg already got that.

 

[nutty_gnome]

Sorry about your beer... but your predicament with your sister made me think of this:

[ame]https://www.youtube.com/watch?v=ZZAWhN6iHWs[/ame]

 

[Gavin C]

All of my software recommends this ratio, though I use 1.35 lbs/gal in order to collect wort for future yeast starters. I do know a bit more volume will increase the efficiency especially in higher gravity beers (>1.060).

per quart not gallon. It think is what the OP is meaning.

 

[TAK]

per quart not gallon. It think is what the OP is meaning.

Actually, per lb. He probably means 1.25 qts of water / lb of grain.

 

[chickypad]

All of my software recommends this ratio, though I use 1.35 lbs/gal in order to collect wort for future yeast starters. I do know a bit more volume will increase the efficiency especially in higher gravity beers (>1.060).

Yes, you seem to have this backwards. I've never in all the literature or calculators I've used seen it expressed as weight per volume. It's always the other way around - qt/lb or liter/kg if doing metric. Like TAK said the 1.25 is very likely qt per lb (which would be 3.2 lb per gallon if you were for some reason using that measure).

 

[Gavin C]

Actually, per lb. He probably means 1.25 qts of water / lb of grain.

Yea. That makes more sense. :smack:

 

[hvjackson]

[...]
Taking preboil gravity readings isn't a step I've routinely done. In this instance, I did not. Sorry.

Taking a pre-boil gravity read is a great way to sanity check your process. (Note that it will be lower than your expected OG since you still have to boil off some water. Software will tell you what to expect or you can do the math by hand.)

If your pre-boil gravity is lower than expected you have a few options:

- Add some malt extract to bring you up to the right gravity. This is probably the easiest, but if your recipe has a lot of specialty grains it won't give you the exact right grain bill. (Probably not a big deal if you're only talking 10-20%... if you've missed your pre-boil gravity by 50% you may notice).
- Boil for a while before starting your hop additions to drive off some of the liquid and concentrate the wort. You will end up with less beer but it will be the right specs.
- See if you can get any more sugar out of the grain by sparging more water. In this case you will also want to boil more to get down to your expected pre-boil volume. (Not sure if this is feasible with BIAB since I'm not that familiar with it.)

In my opinion, taking lots of readings all through the process is really helpful when trying to troubleshoot issues and get things back on track. If you don't find out your gravity is off until you have the beer in the fermenter there's basically nothing you can do at that point.

 

[TAK]

^ +1 to this.

Taking a preboil and adjusting before you boil is, IMHO, a very simple next level type of thing I encourage anyone to do. It helps you hone in process and hit the numbers of what you intended to brew. If I didn't hit my target preboil, add DME (or maybe more sugar if it's already in the recipe). If I overshoot, I usually even dilute back down to my preboil gravity and throw out (or repurpose) the extra wort so I don't under pitch as a result of increased volume.

 

[catdaddy66]

per quart not gallon. It think is what the OP is meaning.

You're right! Thanks for the correction

 

[TheGreatRoad]

Thanks for all the suggestions and guidance on this issue. I'll definitely be making some adjustments before and during my next batch.

But even though I've been having these issues, the beer still tastes great and on target flavor wise at least. Thanks again everyone.

 

[TxBigHops]

Actually, per lb. He probably means 1.25 qts of water / lb of grain.

Yes, but even this is only the mash water. Doesn't consider additional water needed for sparge. For a guy asking for help, he's pretty slow to answer questions or provide the needed information. He seems to either be trolling us, or he doesn't understand the very basics of brewing beer. Didn't tell us his batch size or the quantities of water he used. As was stated, 9 pounds of grain is way too little for a normal 5 gallon batch of beer to get to an OG of 1.085. If he's making some other quantity, he needs to state that at the time he asks his initial question. My conclusion is he's yanking our chains.

 

[TheGreatRoad]

Not yanking anyone's chain. When I went back to provide additional details, it forced me to see the bonehead mistake(s) I was making. I stated as much and thanked everyone for their help.

 

[max384]

What batch size??????

 

[TheGreatRoad]

It was a 2.5 G batch.