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The Partial Mash
by Matthew Jackson

So, for whatever reason, maybe you decided that you're not exactly satisfied with what your getting from extracts. Maybe you decided that you could do it better. . . whatever the reason, you've decided to check out grain brewing.


Just one second. . . bad things happen from jumping right on into all grain. So, where are you supposed to go then? Well, there is a middle ground in brewing called partial mash brewing. A partial mash is a brewing system wherein you have a part of your wort (pre-fermented beer) derived from grain and part from extract. It is a great way to get the hang of mashing, with a safety net. See, with an all grain mash, your timing and temperature control is everything. If you're not used to it, you could over-heat your mash or leave it too long at a given temperature and ruin all of your efforts. With partial mashing, you are not completely at a loss because you've still got the extract. True enough, the beer will not be as good as you thought it would be, but it'll be drinkable. So live and learn. . .

As previously stated, the primary difference between a mash and a partial mash brewing method is the use of extract. The partial mash system is sort of like a stepping-stone into the more advanced system of full grain mash. On the other hand, some stay with partial mash for its simplicity and lack of required time. The primary reason someone chooses partial mash to all extract is, in a nutshell, more control. Most people can turn out a fair to decent batch of homebrew with a hopped extract kit and a packet of dry yeast. However, after a round or two with "kit" beers, you will probably get the urge to explore further, after all, was it no the drive for better beer that got you that first can of extract in the first place?

Well, great. Partial mash. . . lets do that then. "How?" you might ask. . . well, that's why you're here isn't it. So lets get started, shall we? First, let's assume that you have already gotten at least a basic brew setup. Here is the simple brewing necessities: A copy of "the New Complete Joy of Brewing" by Charlie Papazian (if you don't have this. . . stop what you're doing click here and get it now), a boiling pot, a fermenter, and a bottling bucket. Other hardware should include a siphon (an auto-siphon is highly recommended), a stirring spoon (not wood), some form of sanitizer (Iodophor and B- Brite are both excellent choices. Check them out here), a thermometer, some bottles and caps, and lastly a capper. This is your basic rig for kit brewing.

For partial mash you'll need some extra hardware on top of this. You will also need a lauder-tun. The principles of a lauder-tun are simple. Really, it is nothing more than a strainer of sorts, to strain your mash with hot water. This can be as impressive or cheap as you like it. For people like me who love showing off their stuff, a 10 gal stainless steel pot with a welded false bottom and a ball valve connector running straight into the boiling kettle looks as good as it works. However, that's a might excessive for someone just starting with grain. There are modified Colemen coolers rigged up as a lauder-tun for sale just about anywhere, it's perfect for the grain brewer needs. In the book "The New Complete Joy of Brewing" Charlie walks you through how to make a lauder-tun with two food grade buckets. It's ugly, but wonderfully functional. Lastly, you could use a large grain bag, like this one for partial. However, if our grain bill gets bigger than say 2.5 lbs. get or make a larger volume lauder-tun. So, get or make your lauder-tun and lets get a move on.

So, here's your checklist:

  1. "The New Complete Joy of Brewing" by Charlie Papazian
  2. A lauder-tun (5-6 gallons)
  3. A brewing kettle (5 - 6 gallons)
  4. Plastic or glass fermenter (6 gallons at least)
  5. Secondary fermenter (This is optional but good to have for lagering or clarity)
  6. Siphon
  7. Thermometer
  8. Kitchen timer
  9. Sanitizer (bleach works, but requires a longer soak and a good rinse)
  10. Iodine (I'll explain that later)
  11. Capper
  12. Caps
  13. Bottles
  14. Air lock
  15. Brew Additives (e.g. Irish Moss and gypsum)
  16. Hydrometer

Go through and get that which you do not have. We'll wait.

Ok, now that you've got your checklist filled out, lets mash!

Here's your grocery list. This is for a European Pilsner:

WARNING! A pilsner is a lager. . . that's German for "wait". This takes about 6 -8 weeks to do right. If you are impatient try an ale. You'll find many good recipes here.

  1. 3.3 lbs. Of light unhopped liquid malt extract (3 lbs of dry if that's your thing)
  2. 2 lbs two-row malt (or pilsner malt if you can find it)
  3. .75 oz Saaz hops (bittering)
  4. .5 cascade hops (flavor)
  5. .5 Saaz hops (aroma)
  6. 1 tsp. Irish moss
  7. .75 cup priming sugar
  8. White Labs Pilsner Lager tube

As a rule of thumb, Irish moss and gypsum are two things you should have on hand in "bulk"; meaning that you have a larger than one or two use amounts hanging around. For lighter color beers, it's a must.

If you noticed the shameless White Labs pitchable yeast plug, quit complaining about it and get it in liquid form anyway. It's a lager and for a lager, liquid lager yeast is the only way to go. If your more familiar with the Wyeast "smack Pack" then do that, but try to avoid dry yeast with a lager. . . it can be done, I'm just not recommending it. Ales are great with dry yeast, lagers can be a bit more unpredictable.

For an ale or lager, the brewing method is the same. It's the storing temperatures and bottling times that change. Follow your recipe. . . it'll more than likely be right.

Ok, so you've got your groceries and are now ready to dive in to mashing. . . cool. Here's what we're going to do. First, Get your yeast starter going. Its not just a good idea, it'll make for a consistently better beer. You can find how to do that here. Now start a gallon of water on the stove or burner. DO NOT BRING TO BOIL! You want it around 125 degrees or so, and yes have your thermometer in the pot with the water. While your waiting, did you get pre-cracked grains? If not, here's when you need to crack them. Use a counter top and a rolling pin. Do not pulverize the grain. It will turn into mush and mush isn't easily strained; just crack them up. It does require a bit of arm strength, because they need to be broken up. If your arms are sore after this, may it serve as a reminder to buy them cracked. When the water hits the 125 mark, add your grain. The temperature of the water should drop a bit with the grain, its normal and in a way good thing, so don't worry about it. Keep the water at a steady 120 degrees for 30 minutes or so, stirring every 5 minutes. Now is a good time to crack open a brew, and enjoy the moment. . .

While enjoying the moment, in a separate kettle, get a gallon and a half of water heated up to 170 degrees.

After 30 minutes, raise the temperature of the mash water to 150 degrees and hold for 10 minutes. Then raise the temperature again to 158 degrees and hold for 20 minutes or so. Ok, so here is where the iodine comes into play. Take a sample, a small sample from your mash. Put a drop in a white plate, and then drop some iodine into it. If it turns black, your not done yet. Continue at 158 for up to 20 more minutes.

Ok, so what's with the iodine? Basically, the starches in the grains are getting converted to sugar during this process of temperature adjustment. Iodine reacts with starch, but not sugar, so if the iodine turned black, you still have a bit of starch to convert. If you still have some starch conversion left it can go at 158 for another 20 minutes, BUT DO NOT EXEED MORE THAN ANOTHER 20 MINUTES!

Ok, remember that second pot of water you've kept at 170 degrees? Find your lauder-tun, drain your mash water into the lauder-tun trying not to splash a whole lot. Then empty your second pot into your lauder-tun on top of the mash water. This is called "sparging" by the way. The idea of sparging is to run more water over your now spent grain to get all the sugary goodness out of them. Drain your first gallon of wort into a container, and send it back through for clarity. Now drain the rest of the wort back into the brew kettle and add the extract. Stir the extract until it is not clumped up at the bottom any more. That would lead to scorching the malt, and adding a darker color and slightly burned caramel flavor to your beer. Now add the first round of hops for bitter. Bring the wort to boil set your kitchen timer for 30 minutes. Now is a good time to sanitize your primary fermenter, air lock, hosing, and lid. It's simple enough to follow the instructions on the packet, but it is of absolute importance that you sterilize your equipment. After 30 minutes is up, add the second hops for flavor and Irish moss, and set your kitchen timer for 20 minutes. Now add the last bit of hops for aroma and set your kitchen timer for 10 minutes. If you use an emersion wort chiller, now is the time to put it into the boiling wort.

You want to get the wort down to 100 degrees as fast as possible. If you have a wort chiller great, use it. If not, put your brew kettle in a vat (read sink) of ice water and tightly cover it. It might be suggested that opening and stirring the wort every now and again, around every 5 -10 minutes or so will expedite the cooling process. If the sink of ice water is used, keep a steady flow of cold water or replenish your ice often in order to keep the ambient temperature as cold as possible. You did leave that thermometer in the kettle right? Around 30 minutes or while your stirring for the third or fourth time, check your wort's temperature and see if it's below 100 degrees. If so, add it to your fermenter and top off to 5 gallons with cold water. Splashing around the water and wort into the fermenter is encouraged to the point of not making a mess, but getting plenty of air. At about 70 degrees take a hydrometer reading. This is your original gravity (O.G.) write it down in your log. Now Pitch your activated yeast assuming it is showing signs of heavy activity, and put the lid with the air lock on the fermenter. Don't forget to put sanitized water in your air lock.

Now here is the hard part. . . wait. Keep the fermentation temperature around 50-65 degrees for around 4 days or so. Now put the fermenting beer into the secondary fermenter and put the lid with an airlock on it and store at 45-55 degrees for around four weeks before bottling. Mark it your calendar, with big letters BOTTLING DAY!

Here is an important note about playing with a hydrometer. First, follow the instructions and all will be well. Second, don't stick it in your beer, get a sample and use it. Some people use a glass beaker for this, I use the plastic tube the hydrometer comes in. Lastly, never ever put the test beer back into the batch, unless you want a beer that smells a lot like locker room slime extract stained through a sweaty gym sock. Inevitably, the sample is contaminated, and really. . . it is just not worth it to save the half-cup your testing. If you feel that strongly about wasting beer, drink it. A good rule of thumb here would be: if it tastes better at room temperature and flat that most beer you can get at the store, your doing good!

On the day before bottling day, take a hydrometer reading of your beer, and write it down. Now, on bottling day, take another hydrometer test. Is it the same as yesterdays? If your hydrometer reading is the same as yesterday, your ready to bottle, and if not, its still fermenting a bit to lively to bottle right yet. When you can get two days to read the same this is called your final gravity (F.G.), its time to bottle. Take care to sanitize all of your bottles, caps and tubing before you touch the beer with them. If you have a bottle filler groovy, sanitize it too. The biggest thing to remember is to sanitize everything that touches your beer. Yes at this point it is beer, it's flat and warm, but its beer. Heat up to boil a quart of water. At about 10 minutes of boiling add priming sugar and stir until all sugar is gone. Cool the water in an ice bath until around 70-ish degrees. Then pitch it into the beer, and stir a little bit. Now bottle it. Put the bottles in a refrigerator and now wait again. . .

Two weeks in a refrigerator, and your European pilsner is drinkable. Enjoy.



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