Partial Mash: The best home brew technique! for most home brewers!

Delicious Cream Ale.

What if I told you there was a method that produced beer that was nearly indistinguishable from all grain home brew.  A method that made competition worthy beer.  A method that allowed you to hit your numbers almost every single time?    What if I told you this method was easier than all grain?  The beer on the left is an amazing cream ale that we make partial mash.  It is one of my favorite beers.  Perfect for watching a football game.

Well there is.  The method is called partial mash.  And it is by far the best method for everyday brewing.   We field lots of questions and comments on this blog.  Not all of which are public.   The questions are almost always about all grain, and the comments are almost always related to efficiency, attenuation, and consistency.    We used the exact same grains, we treated the water the exact same way, we used the same hops... our numbers weren't even close.   Well yeah, there are so many factors that can effect the extraction of sugar from grains.  Factors like pH, temperature, freshness of the grains, consistency of the mash temperature, attentiveness of the brewer, mechanical manipulation of the mash... the list is long.   So long in fact that many brewers are spending thousands of dollars on all grain wort production machines.  These machines handle a lot of those factors for you.

All you need for Partial Mash!

But what if you didn't need to spend that kind of money.  What if learning some basics was all you needed to do to make great beer?   That is what partial mash does for you.  Partial mash allows you to make beer with real all grain flavor, and to make it nearly identically every time.  Understand some of the techniques associated with partial mash are different than the techniques you use with all grain. Please notice I didn't say lesser, or inferior.  Just different.

Partial mash in a nut shell:  A portion of the sugars come from a mash of grains and the other portion comes from malt extract.  It is that simple.   You perform a mash of grains, then you supplement with malt extract to achieve your final gravity. I have done up to 75% of my sugars from grain.

Now there are some challenges of working with malt extract.  First of all, the ferment-ability of malt extract wort can be lower than that of all grain wort.  This isn't a huge issue when we do partial mash, because most of our sugars 50%-75% come from the grains.  So you need to use very light colored malt extract, it is more ferment-able.  The ferment-ability has to do with the drying process, and the production of the wort.  The darker the extract the less ferment-able the wort.   And we adjust for the ferment-ability of the wort on our software by lowering the attenuation by a couple of points.  Having said that we are able to produce crisp dry lagers with partial mash.  We had a champagne lager go from 1.056 to 1.012.  That is crisp enough for me.    Second,  Malt extract wort will be darker than all grain wort.   So you need to account for that.     We never get color from malt extract (except in our BDSA where we want some sweetness).   We always try to use Pilsen, Maris Otter, or Extra Light extract.  In the recipe below you will note that there is no crystal grain at all. There is no need for it. The wort will be a point or two darker than your software indicates any way.  Again, the key is to get your color from the grains, not from the malt extract.  Finally,  freshness matters.  if you are not ordering from a very busy home brew store, you should probably use dry malt extract.  It  has a much better shelf life.

Fresh Light LME is highly
ferment-able!

But what extract should I choose.   The answer is always the same.  If you can get fresh LME (truly actually fresh) then it is more ferment-able than dry malt extract.  But in 27 years of brewing I have seen truly fresh malt extract at a LHBS maybe 2 or three times.  So I usually use extra light DME.  Listen to me on this point it is very important you will hear people say that malt extract leaves your beer sweet... and ... wait for it... they are right and wrong.   Modern extracts are from 65% to 75% ferment-able.  They should not really be the sole source of sugars in your beer.   The production and manufacturing process does leave some un-ferment-able sugars in the wort.  But so does your current process.  If you can get to 80% fermentation with an all grain (no additional sugar) wort, you are a true hero.   Most of you don't get that close.  Most of you don't take a truly representative gravity reading before pitching yeast.

I know this because I have fielded this question at least a dozen times. We undershot our gravity but we still didn't get truly great attenuation.  The yeast manufacturer sad we should be at 75% and we only got to 70%, what can we do?  Uh, well you can transfer prior to taking a gravity reading to make sure that your wort is homogeneous.  You can take samples at different depths in your boil kettle.  And or you can accept that to make a truly ferment-able all grain wort you need to really learn to pay attention to your mash.  Or, you can just learn to use partial mash.

So how do I make clean well attenuated crisp beers with partial mash?   It is simple really.  I use a lot of grain, I use some extra light DME and then a portion of my ferment-ables comes from sugar.  Every time?  you use sugar every time?  Yes, just about every time there is a sugar addition at high krausen in order to get the yeast rocking again and to make them finish strong.  Yes this is different than all grain.  Usually in all grain I set it and forget it.  But hey, you should be watching your fermentation like a hawk anyway.

Here is an example. (by the way for fun, add 1 # of wheat, change to Pilsen DME and use Saison yeast sometime with this recipe, trust me you will thank me when you try it)

Wheeler Street Cream Ale!

Wheeler Street Cream Ale
Classic American Cream Ale
5 Gallon
Partial Mash
1.048 OG
1.007 FG
3 SRM
17-19 IBUs

5.0 # Pale Ale Malt
1.5 # Flaked Corn
2.0 # Extra Light DME added in last 10 minutes pre dissolved in other water
0.5 # of Corn Sugar added at high Krausen dissolved in a quart of preboiled water.
.2 oz of Magnum - at 60 minutes or any neutral bittering hop to give 2.6 AAUs to the boil
.5 oz of Liberty - at 30 minutes
1 tsp of yeast nutrient at 10 minutes
1 tsp of Irish Moss at 10 minutes
.5 oz of Liberty at 5 minutes

US 05 yeast.

In a brew bag, mash your grains in 3.75 gallons of water at 150 F for 60 minutes. (I use 5.2 stabilizer when I brew partial mash.  In another pots, dissolve the DME in 1.7 gallons of water. And very slowly bring it to 190 F.   In yet another heat 1.75 gallons of water to 168 F,  this is your sparge water.

At the end of your mash pull the grains and set them on a rack or a colander above the kettle.  Add the dissolved DME to the kettle.  Sparge the grains with the 168 F water until you reach pre boil volume.  From here on it is just like any other batch of beer.

Other recipes that work great with partial mash... any dark semi sweet beer.   BDSA, sweet stout, bock, dopple bock, porter, RIS, barley wine...  Any beer really, just another learning curve.   But a process that is faster and more consistent than all grain brewing.

So there it is again a defense of partial mash.