So, I know there were lots of things I could have done to repair the situation had I been prepared (lesson learned, I'll be having DME on hand from here on out), but I'm a little more interested in what might have caused the problem and how I might prevent it in future all grain brews. Anyway, here's the grain bill:

10lbs Maris Otter
3 lbs Rye
1 lb Crystal Rye
8 oz. Rice Hulls

Dough-in was at 167 degrees with 4.5 gallons, and I hit my target mash temp of 153 right on the dot. Held with a loss of one degree through the entire hour-long mash. It took three vorlauf to clear and then I drained the first runnings.

Something weird did happen here. At first, I thought I was stuck, when the wort stopped draining at maybe 2 gallons. Opened the tun cut the grain bed a bit and it really looked like my grain had absorbed most of the water. So, I figured, sparge time. I don't have any grades on my brew kettle, but I think I had maybe 2.5 gallons, tops.

Had my 4 gallons of sparge water at 175 and started batching in immediately. I stirred, let the sparge water sit for about fifteen minutes, and then began sparging. The second runnings were extremely light, way lighter than the original wort. I've had that happen before, but the color change was never quite this dramatic.

Anyway, sparge finished and I had about 6 gallons in the kettle. Probably should have measured gravity then (not that I could have done anything about it), but I started the boil.

After boil and cooling, I had 3.5 gallons of wort at 1.053. OG should have been 1.072 and I should have had 5.5 gallons post boil.

What in the world did I do wrong?

  • Oh, I should mention that I made everything dramatically worse by adding top up water to get to five gallons, dropping the OG to 1.035. Apr 8, 2013 at 10:51
  • How long was your boil? I usuaully start at 6 and end up with about a gallon of loss over the couse of an hour. Not that it would effect efficiecny, but seems odd to start with 6 and end at 3.5
    – DHough
    Apr 8, 2013 at 22:23
  • It was an hour. I don't have grades on my brew kettle, I'm just guestimating on the actual preboil volume. I should have checked the gravity before I started boiling, but I honestly thought, with it so severely reduced, that I'd have wort at, like, 1.090 or something. I mean, the first runnings were freaking thick. Apr 9, 2013 at 2:45
  • So, I just want to add a wrinkle to this whole thing. The dang thing's been fermenting (and way warmer than I'd have liked due to an equipment malfunction---we're talking 74 degrees) now for 72 hours. Either my initial gravity calculations were WAY off, or something else is going on. My SG right now is 1.020. So, I've only dropped about 15 points. Apr 10, 2013 at 21:47

1 Answer 1


There's something fishy about your numbers here. For example, to get a OG of 1.072 with your grain bill I need to assume 80% efficiency. Is that what you're used to getting?

As far as the source of your problem, it could be any number of things and right now we're only going to be able to guess. If in the future you take gravity readings throughout the process (first runnings, sparge runnings, kettle gravity, etc.) there's far more diagnostic work that we can do.

Are you sure your water measurements were correct? Have you changed anything about your grain supplier or crush?

  • Yeah, I usually get between 75-85% efficiency. And, I've learned a crapload of lessons with this brew: test everything all the time and have DME on hand in case something like this happens. I think I got my water measurements correct. I used BeerSmith, and it's never steered me wrong. I did use a different grain supplier, Midwest. I've never had a problem with the crush provided by a grain provider, so it's hard for me to suspect them. But I guess that could have happened. Thanks for the reply! Apr 8, 2013 at 13:22
  • Hmm...anecdotally, I know Midwest was having problems with their crush a few weeks back.
    – MalFet
    Apr 8, 2013 at 13:50
  • Curious... coincidentally, I ordered a few weeks ago. Well, that's a kick in the teeth. Apr 8, 2013 at 14:00
  • I don't suppose it's possible that I should have mashed longer due to the percentage of rye? Also, should I contact Midwest, or is that a lost cause? Apr 8, 2013 at 14:16
  • I doubt the rye made a difference. At this point, honestly, it's hard to know where your efficiency losses went. The fact that you only got two gallons from your first runnings is also strange, but wouldn't necessarily result from a poor crush. It's likely that you had conversion problems, but you'll probably never know exactly why in retrospect.
    – MalFet
    Apr 8, 2013 at 14:56

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