Author Topic: Examining Oxygen Ingress: Should I Pre-boil?  (Read 4653 times)

Offline bucknut

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Re: Examining Oxygen Ingress: Should I Pre-boil?
« Reply #45 on: July 15, 2017, 09:26:45 PM »
What exactly is meant by mash cap? Also how long do you pre-boil your mash water?

Offline HoosierBrew

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Re: Examining Oxygen Ingress: Should I Pre-boil?
« Reply #46 on: July 15, 2017, 11:18:40 PM »
What exactly is meant by mash cap? Also how long do you pre-boil your mash water?


A mash cap greatly reduces or eliminates O2 contact with your mash. It covers the mash mixture by direct contact, ideally covering the entire interior surface of your mash tun. Depending on the shape of your mash tun, it might be pie or pizza baking sheets, or in my case a piece of 2" Styrofoam covered with aluminum tape.

As for preboiling, I boil 5 minutes then cool to 200F, add acid and water salts, then continue cooling down to strike temp.
Jon H.

Offline braufessor

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Re: Examining Oxygen Ingress: Should I Pre-boil?
« Reply #47 on: July 16, 2017, 01:48:52 PM »



As for preboiling, I boil 5 minutes then cool to 200F, add acid and water salts, then continue cooling down to strike temp.

Question - is it a problem to add acid/salts right away, then boil, then cool?  Does the boiling have any effect on the additions or their role in mash pH, etc???  Never really gave it any thought, but saw you mentioned you don't add them until after the boiling and cooling has started.

Offline JJeffers09

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Re: Examining Oxygen Ingress: Should I Pre-boil?
« Reply #48 on: July 16, 2017, 02:58:58 PM »
I have read and have seen that it is best to add salts preboil and acidity from whatever method you choose after.  So I am curiously awaiting your answer to Jons ?

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Offline HoosierBrew

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Re: Examining Oxygen Ingress: Should I Pre-boil?
« Reply #49 on: July 16, 2017, 03:55:16 PM »



As for preboiling, I boil 5 minutes then cool to 200F, add acid and water salts, then continue cooling down to strike temp.

Question - is it a problem to add acid/salts right away, then boil, then cool?  Does the boiling have any effect on the additions or their role in mash pH, etc???  Never really gave it any thought, but saw you mentioned you don't add them until after the boiling and cooling has started.



My understanding is that adding the salts before the 5 minute preboil can cause some of the salts to come out of solution and precipitate, thereby altering your target mash pH. As for the acid, it's just easier for me to add everything after cooling to 200F - one less step to forget. And the steps outlined on the low ox brewing site have worked well and I see no reason to deviate. 

Edit -   http://www.lowoxygenbrewing.com/low-oxygen-methods/
Jon H.