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How do you convert extract to Partial Mash?

Hey there folks,

I have been brewing extract for well over a year, and since it will be a while until I can fork over the cash for an all grain system - I was hoping to learn how to convert my favorite extract kits to mini-mashes.

Is there a rule of thumb for this? Some kind of equation?

Thanks for the help!

Check out Brew in a Bag on the Brewing TV! If you want to make a larger batch you can halve and halve extract and BIAB.

Not too tough with a little research.

Base malt is 36pts/lb but you only get around 75% efficiency so figure 27pts/lb. Sub for DME that’s 40pts/lb, or LME thats 32pts/lb. That means you need about 1.5lb of malt to substitute for a pound of DME, and 1.2lb of malt to equal a pound of LME. That’ll get you close enough.

I also just figure my total pounds of malt as 36pts/lb, and don’t worry about the specialty grains being a little lower.

As for how much of the DME to sub with your mash, thats up to you. I would definitely mash all the specialty grains with the base malt though. You get better flavor this way.

you can start AG with as little as $30…i did.

5 gallon cooler at wally world: 19.95
5 gallon paint strainer bags at HD; 2 for $4.
hose, valve, bung at NB…about $5.

some pics and text here:

You can easily mash 6-8 lbs of grain in a 5 gallon cooler.
Mash and sparge with 9-10 quarts water each.
Preboil volume in a 5 gallon extract pot: 15-17 qts. (if i get closer to 17, i either split the boil by keeping up to 14 in the 5 gallon pot and moving the excess to a smaller pot (I boil both and combine at approx 45 as there is now plenty of room in the 5 gallon pot); or, boil 14 in extract pot and freeze excess for use as a starter.) Post boil volume is usually 2.75-3.5 gallons

I also sometimes take a 5 gallon batch (recipes that have 12+ pounds of grain) and just split every thing in two and do two complete brews in the same session. This requires 2 mashes, 2 sparges, and 2 boils for a full 5 gallon batch in the fermentor. It makes for a slightly longer day, but not much longer as the second is mashing while the first is boiling. But, lately i’ve just been doing 3.0-3.5 gallon batches so just 1 mash,sparge, boil.

Anyway, it’s not that expensive if you either do 2x half batches or 1x small batch as the volume of the final wort is similar to your extract so no big pot or IC is required. Plus, it can all be done in the kitchen…year round. :wink:

just a thought.


I find it easier to go from all grain to partial mash. Just look up NB’s all grain recipe if for the recipe you want to convert to partial mash. You’ll need to know how much total grain you can mash in your setup.

Mash all the specialty grains (roasted malts, crystal, etc). Then add as much of the base malt as you can to get to your max grain mashing ability. Take the balance of the base malt and convert it to light DME.

lbs of left over base malt x .67 = amount of DME you’ll need.
lbs of left over base malt x .75 = amount of LME you’ll need.
But I would always use Pilsen light DME.

It’s that easy!

Another easy way would be to load a recipe into a brewing program (I use hopville) and take note of the OG. Then just adjust the amounts of base malt down and extract up to get you back to the original gravity. Or do it in reverse if going from extract to all grain. But that can be more tricky because extracts can have different percentages of different grains depending on the brand. Another reason why it’s easier to go from all grain to partial mash.

If you have a specific recipe I’d be happy to load it into hopville as all grain, then convert it to partial mash and send you links to the different recipes. All I’d need to know is the recipe and what is the max amount of grain you can mash.

+1 I also think it’s easier starting with AG. Add 3 lbs of DME or 3.3 LME and cut the base grains down till you hit you SG using a brewing software program. BeerSmith is good. Follow the mash temps on the AG. You may even want to up your base grain a bit in case you’re a little short on conversion. Which you probably will be the first couple of times. Everything else is the same.

I’ll use one pound of dme

About 4.5 lbs of grain

7 quarts of water each for mash and sparge

I use a 5 gallon round cooler with steel braid for my tun

That basic ratio will generally start you with a 3 ABV beer

Depending on your brew kettle size and some other factors, you can adjust for more or less grain, extract, adjuncts, etc…my beers are on average 5 ABV, estimated

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