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Double Brew, One Mash

My Kolsch and IPA brew session went of without a hitch last Friday night.  Today, almost a week later both beers are almost quiet with their fermentation activity, but I’ll continue to let them set for another week before I rack them into kegs.   I may dry hop the IPA with 2oz of Cascade plugs I have.  And I need to get that Kolsch chilled down for some cold conditioning.

During this session I brewed the two beers from the same mash.  Doing this saves some time and allows me to get two full beers out of one mash session.  I have two burners to use so I can split the total wort and then boil the two worts at the same time.  I have done this double sized mash a couple times and I find it works really well for me.

In my Kolsch recipe it called for base malt (Pils), some Munich and some CaraPils.  That is a pretty simple grain base that I felt would work also as a base for a clean American style pale ale like IPA.  My IPA recipe reflects that base and also has the addition of some crystal 120L in it to get more of that crystal malt flavor that I like in a pale ale.  My approach with the double sized mash then is to mash with enough grain to generate enough wort to cover both batches.  In this case I needed about 13 gallons of wort.  I calculate the amount of grain needed to be sure to hit the gravity of the highest of the two OGs (in this case the IPA at 1.060).  Then I can dilute down some of the resultant wort with water to get to the appropriate pre-boil gravity of the lower gravity beer ( in this case the Kolsch at 1.040).

Once I had collected all the wort I needed, I diluted the wort for the Kolsch and started the boil.  For the IPA wort, I placed the 0.5lb of Crystal 120L in a grain bag and steeped in in the wort for 30-40 minutes. At the same time, I started the boil in the Kolsch.  A second advantage to this steeping phase is that it helps set up my chiller process.  If you start both beers at the same time, then one beer will have to sit hot while you chill the first one down.  In this session, I steeped for about 40 minutes in the IPA.  This builds in a 40 minutes buffer for me to get the Kolsch chilled and transferred at the end of its boil before I need to start chilling the IPA.

Essentially this double mash session is like using a big batch of extract wort that you would then use with specialty grains to get the beer you want.  The greatest difference here is that I am using an all-grain process to control the mash profile of the wort I am making (which you can’t get with extracts) and I am controling the freshness of that wort (which you are always unsure of with extracts).  I have used this techinque to mash in a large batch of English Pale malt to make a porter and an English Pale.  The variations are endless.  It’s just like doing extract with grains.  I think that this technique is a great way to get double the production with just a little more work (essentially just the staggered start times difference for chilling).  Try it out for yourself and let us know how it works out for you.  Just be prepared to now have twice the beer on hand after each brew session.


American IPA Recipe


Bottling Homebrew

1 Comment

  1. travis

    Interesting take on the double brew day. We were talking about doing a 20 gallon batch and this might be a great way to pull that off.

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