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Mashing as I write!

Post #1 made 15 years ago
by 2trout
Well, My first "true" biab is busy mashing away in the garage. Ive been taking photos/measurements etc, along the way. So with any luck Ill be posting a bit of a photo essay of my first real biab. Im relaxing, having a brew :smoke: , and wondering about the 90min vs 60 min. boil. Being a green sort of fellow, I was thinking :scratch: : "the 90 min boil will use 30% more propane than a 60 min. boil." So why the extra length?
"All I know is that the beer is good and people clamor for it. OK, it's free and that has something to do with it."
Bobbrews
    • BME Brewer With Over 5 Brews From United States of America

Post #2 made 15 years ago
by hashie
I get my gas for free, so don't worry about gas use with longer boils.

Even if I paid for the gas, it still is less than $5 AU per brew in gas costs.
"It's beer Jim, but not as we know it."

Post #3 made 15 years ago
by stux
One of the reasons for doing a 90min boil is to drive off the DMS precursors as Joshua referred to.

John Palmer said in a recent podcast I listened to that the DMS precursors have a half-life of 38mins in the boil, so after 114 mins of boiling you've virtually eliminated them.

90 mins is close enough for most purposes.

Basically Pilsner malts are very lighty kilned and so have the DMS precursors (SMM?), where as most other malts are more kilned and the SMM is destroyed during kilning.

So, they said, if you have a high proportion of pilsner malt, then use a 90 minute boil, otherwise 60 minutes should be okay.

Another reason for a longer boil is to enhance the Mailard reactions, which gives a browning/caramelizing like effect, which is like the toastyness you get in Melanoidin malt.

So, if you don't have a lot of pilsner malt, then you can do a 60 minute boil, but if you do, then you should do a 90 minute boil.

BUT they also say you don't need a crazy boil, just a gentle rolling boil, as long as the surface is moving and you have full convection, that is fine.

Using just enough gas power to maintain this gentle boil will save a lot of gas.

I also save gas by filling up my pot with hotwater from a solar heater so I only have to get the water from 55C to 65c then to 100C rather than from 20C which would be the cold tapwater.
Fermenting: -
Cubed: -
Stirplate: -
On Tap: NS Summer Ale III (WY1272), Landlord III (WY1469), Fighter's 70/- II (WY1272), Roast Porter (WY1028), Cider, Soda
Next: Munich Helles III

5/7/12

Post #4 made 15 years ago
by 2trout
Stux!

Excellent answer :salute: . All extreeeeeeemly helpful info. Thanks!
"All I know is that the beer is good and people clamor for it. OK, it's free and that has something to do with it."
Bobbrews
    • BME Brewer With Over 5 Brews From United States of America
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