I brewed this recipe but substituted crystal 80 for the crystal 15. I did the full mash option, and I doubled all the ingredients and did a 10 gallon batch.

I got an OG of 1.045 at 75F so adjusted to 1.047.

I mashed in at 160F.

What did I do wrong to have such a low OG?

Ruination IPA clone (Stone Brewing Company) (5 gallons/19 L) OG = 1.075 FG = 1.010 IBU = 100+ SRM = 6 ABV =7.7%

6.6 lbs. (3 kg)Northwestern gold (light) malt extract syrup 2.0 lbs. (0.9 kg) Northwestern gold (light) dry malt extract 1.0 lb. (0.45 kg) Briess 2-row malt 1 lb. (0.45 kg) Briess crystal malt (1 5 "L) 1 tsp. lrish moss (60 minutes)

36.0 AAU Magnum hops (bittering hop) (2.25 oz./64 g of 16.0% alpha acids) 15.7 AAU Centennial hops (aroma/finishing hop) (1 .5 oz./43 g ot 10.5%o alpha acid) 21.0 AAU Centennial hops (2.0 oz./56 g of 10.5% alpha acid)

White Labs WLPOOl(California Ale) yeast or Wyeast 1056 (American Ale) yeast 0.75 cup of corn sugar (for priming)

Step-by-step Steep the 2 crushed grains in 3 gallons (1 1.4 L) of water at 149 'F (65 'C) for 30 minutes. Remove grains from wort, add Magnum hops, malt syrup and bring to a boil. Add lrish moss and boil for 60 minutes. Add the first addition of Centennial hops at the end of the boil, and let steep for 5 minutes. Add wort to 2 gallons (7.6 L) cool water in a sanitary fermenter, and top off with cool water to 5.5 gallons (20.9 L). Cool the wod to 75'F (24 oC), aerate the beer and pitch yeast. Allow the beer to cool over the next few hours to 68 'F (20 'C) and hold at this temperature until the yeast has finished fermentation. Add last addition of Centennial hops for dry hopping. Dry hop for 3 lo 5 days, then bottle your beer, carbonate and enjoy!

All-grain option: Use 14.6 lbs. (6.6 kg) 2-row malt and 1.0 lbs. (0.45 kg) of crystal malt ('15 'L ) in your grain bill. Mash your grains at 149'F (65 'C) for 60 minutes. Collect enough wort to boil for 90 minutes and have a 5.5-gallon (20.9 L) yield (~7 gallons or 26.6 L). Decrease Magnum boiling hops to 1.75 oz. (50 g) to account for higher extraction ratio of a full boil. The remainder of the recipe is the same as above.

1 Answer 1


Assuming you had the right amount of everything, I'm guessing your mash efficiency was off for some reason, so it's time to troubleshoot:

  • 160 'F is fairly high for a mash temperature, generally you want something in the range of 150-155 'F. You may have denatured most of your beta amylase and lost efficiency here.
  • How much water did you use in the mash? I generally shoot for around 1.5-2 quarts/pound of grain, if you were too far out of this range, you might have problems too concentrated or too thin of a mash.
  • How finely milled was the malt? Too coarse of a grind can make some of the sugars less accessible, giving you lower efficiency.
  • How fast did you sparge? With this much grain, you might need an hour or more to get good extraction.
  • How hot was your mash during sparging? Too cold and you may lose some efficiency.
  • Did you check to see that all the starches were converted? Using iodine can tell you if you need to give your mash a little more time to finish conversion.
  • How are the fluid dynamics of your lauter tun? This appendix from John Palmer's How to Brew is useful to review, but basically you want an even flow through the grain bed so that all the grain gets properly rinsed.

Any of these could greatly affect your mash efficiency. Temperature is a big one, although 160 is on the high side, so I would expect still a high gravity reading but less fermentable sugars. Anyway, just look through the list and hopefully something will jump out at you, so you can improve future batches. Good luck!

  • Thanks for the response. To the best of my knowledge, I had enough of all the grains. I did not do the grind, the local supply shop did it for me, but I've not had issues before, of course I've not brewed this recipe before. I just built a new mash tun out of a 10 gallon gatorade cooler, it seemed to work quite well, but I'm not really sure how I would tell what the fluid dynamics through the mash were.
    – applecran
    Jul 19, 2011 at 6:13
  • I had the mash at about 160 during the sparge, I kept an eye on that. The mash was just over an hour. and had as much water as I could fit, which was about 25 literes (quarts) so I guess that could be it. Is a 10 gallon mash tun too small to mash 30lbs of grain?
    – applecran
    Jul 19, 2011 at 6:20
  • On any note, it's fermenting like crazy, actually bubbling out of my carboy's air lock, would like to get better at this and figure it out for next time.
    – applecran
    Jul 19, 2011 at 6:22
  • Ya, you definitely need a larger mash tun to do 30 lbs of grain. You would need around 11 gallons of water in a mash for 30 lbs. I use a 10 gallon cooler for 5 gallon batches, so I would recommend either getting a larger cooler or brewing smaller batches.
    – pjreddie
    Jul 19, 2011 at 20:52
  • Thanks for the info. Might have to use two 10 gallon mash tuns at once.
    – applecran
    Jul 20, 2011 at 17:16

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