what the hell happened to my mash?!

I would appreciate anyone's thoughts on a bad mash day today. 5.5 gallon pale ale batch into the carboy. Used 4 lbs US 2 row, 4 lbs German pils, 1 lb Munich and .5 lbs wheat. My OG should have been 1.050 but was 1.040 (and see refractometer issues below).

I typically get 78% efficiency on my system but changed a couple of things today in hopes of improvement of the beer (not efficiency but wasn't trying to lower it).

I use a barley crusher mill. I haven't changed it from the factory setting, which is supposed to be .38 or .39. though I haven't measured it. That said, my crush tends to be more powdery than what I think it should be, so I ran the drill slower today hoping to have a better crush. The crush looked the same.

Also, I used distilled water instead of my tap, which is pretty hard though should be good for brewing based on taste and chemical report (but my beers aren't tasting great so thought I'd change it up). My recipe was based largely on a Gordon Strong recipe where he uses 15 gallons of distilled with .75 teaspoon of phosphoric acid to adjust pH. I used 12 gallons and added .5 teaspoon of phosphoric as I didn't want to overshoot. I have cheap pH strips from my LHBS with a small range (though just ordered the 4-7 strips!) and the pH showed 4.8, though the water was hot so, as I understand it, that should mean 5.1.

I added 1/2 teaspoon each of gypsum and CaCl (per Gordon's recipe). I mashed at 149 for 75 minutes and my mash pH likewise showed 4.8 on the strips (meaning 5.1?). I did not perform an iodine test.

I batch sparged and probably added about a quart or so too much water.

The recipe called for .5 ounce of Galaxy first wort hop, which I did. My pre-boil gravity was 1.036 on the hydrometer, which I measured just after the boil started. I monitored the gravity with the hydrometer during the boil -- taking up a dropper full, letting it cool for a minute or so, then testing. I boiled for about 110 minutes trying to get the OG up. I was going to be a little short, so added .25 lbs of Belgian candy syrup at 15 hopes hoping to eek out the remaining OG point or two I was missing.

After cooling, I took a hydrometer sample and was at 1.040. Tested with two hydrometers and the refractometer, and the refractometer agreed with the hydrometers at this point.

Not really sure what happened but here are a few questions:

(1) Does hop matter mess with refractometer readings? In addition to the first wort hops, the recipe has a lot of hops. Because of first wort hops, maybe this was a problem from the start? (I tried to make sure the drops looked pretty clear and I took 3 readings each time which were close.)

(2) Did I perhaps not let the wort in the eye dropper cool enough before taking the hydrometer reading (1-2 minutes)? I'm assuming that could be an issue.

(3) If my water pH was actually below 5, would that have this much of an effect on efficiency? Do I also have to worry about attenuation (which would really such given the low OG)?

(4) Any other ideas of what might have happened other than just a bad brew day (for example, could be efficiency be that dependent on the water)?

(5) Any suggestions on what to do now that it's in the fermentor (for example, adding more candy syrup or other sugar)? I'm using the San Diego super yeast and if I get 75-80% attenuation, I'll end up with a low 4 ABV which I can live with but if my attenuation suffers, yeesh.

Sorry for the long post and appreciate any thoughts.

I don't even take post boil readings anymore because it's so hard to get consistent results due to hops and striation of the wort.

For using my refractometer I've found that I have to just put 1 or 2 small drops on it and let it cool for 30 seconds or 1 minute before I get an accurate reading. Too much wort and it seems like it can be off by .10.

As for mash pH, Unless you added a lot of acid you're mash pH was probably closer to 5.3 than 5.1, but if it was actually 5.1 I think that could affect efficiency. Maybe your mash efficiency wasn't really off but your hydrometer and refractometer readings were off due to insufficient wort mixing.

You can also boil up so DME and add it to the carboy during the first couple days of fermentation. I've done it and it worked fine.

Thanks chumpsteak. As for the post boil readings, I let the hops settle out and had pretty clear wort, so I would think those were accurate but certainly am no expert on the effect of hops on such readings. Do you or anyone else have a sense of how much DME could be added to 5 gallons without really impacting flavor? I'm sure there are views on that elsewhere and I'll search, but as long as folks are here I'd appreciate your thoughts.

Did you get a good crush on the wheat? I noticed when I buy my grain from the LBHS that the malt crush is just fine but when I get wheat or rye I need to ask them to run it through twice. I would rather ask them to run it twice than to adjust the mill I know it can be a pain for them to change it there and back every time a customer comes in. Last weekend I was 10 points low but I know its from my crush cause there were a bunch of wheat kernels not crushed and some malt not crushed (the malt was my fault). I ordered this batch online so I wasnt there to see them crush my grain bill. I am working on a mill of my own so I can actually make adjustments to the mill for smaller grains.

You used 100% distilled water? And phosphoric acid? That may have been enough to drop the pH low, depending on the recipe. But maybe not.

If you want to plug in the numbers into a brewing water calculator along with the recipe, it can give you a pretty good guestimate of mash pH.

When I calculate my 5 gallon recipes I use 6.5 gallons for the volume, using qBrew. This is done to allow 1 gallon for boil loss and another half gallon to trub loss in hopes that I can get 5 gallons of cooled clear trub free sweet beer into the fermentor. That's when I take my OG readings, just prior to oxygenating and pitching my yeast starter.

With that said I can only think that your grain crush has something to do with the efficiency more than the type of water used, temperature or pH values you stated in your post. For the 9.5 pounds of grain and strike water your mash needed 3.75 gallons of space in your mash tun to get a 1:25 mash thickness. If you filled the tun to the top your mash thickness went to 1:75 which is on the thin side.

There are calculators out there that tell you how much DME to add to raise your gravity. As for taste, you have to figure that since you're 10 points low your taste has already been affected and your IBUs are probably a little higher than you intended. I would think adding the DME to get you back to your desired OG will help bring the beer back in balance and get you close to where you wanted to be in the first place.

Did you get a good crush on the wheat? I noticed when I buy my grain from the LBHS that the malt crush is just fine but when I get wheat or rye I need to ask them to run it through twice.

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Very good question, particularly given the rather large gap in my mill. I don't recall wheat pieces but will check the leftovers. In any event, 1/2 pound of wheat I'd guess would only be a couple of gravity points.

You used 100% distilled water? And phosphoric acid?

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Yes, taken from a Gordon Strong recipe. And I undershot his phosphoric because I was a little unsure, and even with that was low. I can't find an easy calculator with a quick search but will do so when I have more time.

For the 9.5 pounds of grain and strike water your mash needed 3.75 gallons of space in your mash tun to get a 1:25 mash thickness.

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I started with 1:25 thickness in a 10 gallon cooler. Due to temp loss, I ended up adding two more quarts of water by the end of the mash. So the initial mash I think was ok. After first run-off, I was at about 2.5 gallons in the kettle. As for the batch sparge, I always tend to lose another quart or two I assume to additional absorption so I added 6 gallons of water for the sparge to get to 8 gallons in the kettle (I have a pretty high boil off rate). There was about a quart of additional run off in the mash tun after run off. It definitely seemed like a lot of sparge water but not out of the ordinary for me for a 90+ minute boil and my usual eff is 78%.

Thanks all for the input. Off to kids soccer for rest of the day!

I have started to take an SG reading from the MLT prior to sparging to calculate my Conversion Efficiency (See Kai write-up). If I know the conversion efficiency, then I know any decrease in efficiency is somewhere besides my mash (i.e. sparge issues, pre-boil volume, etc).

You should be able to get conversion efficiencies in the mid 90% range, if you are not, then crush, water ratio, temp control, pH all need to be looked at.

Until you know how well you are converting in the MLT it is hard to troubleshoot.

Thanks Heli. I hadn't heard of that technique. I'll check it out.