The following grains have been mixed together:

  • 1.5 Lb. Maris Otter
  • 10 oz. Vienna
  • 8 oz. Carapils
  • 4 oz. Munich
  • 8 oz. Crystal

Can I mash these together @ 150°F for about 45 minutes then increase the temperature up and let them steep at 165°F or so to gain a higher conversion in the specialty grains?

This will then be brewed with X lbs. of extract.


What you are referring is called multi step mashing or multi rest mashing.

There are many good article about this :

  1. Beersmith
  2. How to brew
  3. stackexchange Reason for step mashing

But to answer your question, yes you can do it. Should you? Take a look at #3 for more information.


You will get full conversion at 150°F. If it will within 45 minutes depends on a lot of other conditions. Mainly pH and water grist ratio. Just do an iodine test to know when it actually done. More time and even a very troubled mash will stil complete.

Increasing to 165°F will denature your enzymes and saccrafication will stop.

"Specialty Grains" usually refers to roasted or Carmel grains. Which have already had thier starches converted in the malting process. Raising to 165 for thier sake will do nothing of benifiet. Their sugars will extract just fine at 150. This is reference to your carapils and Crystal malts.

  • Enzymes will not denature at 165. There is still conversion to be done even with caramel/crystal grains. Not so much with roasted. – Denny Conn Jun 9 '18 at 16:06
  • @DennyConn beta-a is denatured instantly at 165, alpha-a will only last a few minutes. Even at 153° Alpha-a will only last 2 hours. Yes there are some startches in Cara malts, but not much. (malting is halted early to leave some starch). Crystals are roasted and have had thier starches completely converted to sugars in malting. – Evil Zymurgist Jun 9 '18 at 16:30
  • 1
    Well, my last 2 beers mashed at 165 would be surprised to hear that. They were perfectly fermentable. One reached 85% attenuation. And enzymes don't denature instantly...it's not like a switch. – Denny Conn Jun 9 '18 at 16:40
  • @DennyConn they can feature instantly if hot enough. Alpha does take a little time can't find the reference but I recal about 20 minutes at 165°. 169° is about 5 minutes (denature rest). Did you step the mash to 165? If so it was probably complete long before you hit 165. I've had complete conversion in as little as 28 minutes. – Evil Zymurgist Jun 9 '18 at 16:45
  • 1
    charts are great...experience is better – Denny Conn Jun 15 '18 at 15:58

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