Skip to main content

Things I've Learned Brewing with The Grainfather, Part 3

In the previous posts, I've talked about The Grainfather in general, then about mashing and sparging with it. This time, I'm going to talk about the boil and post-boil steps.

The boil process in all-grain brewing is intended to accomplish several things:
  • Extract the bittering, flavor, and aroma compounds from the hops
  • Sterilize the wort by destroying any bacteria or wild yeast that may be in it
  • Concentrate the wort to original gravity level
  • Remove dimethyl sulfide (DMS) from the wort, which would impart a cooked corn, cauliflower, or parsnip aroma and flavor in the beer
  • Stop the enzyme activity that converts starches to sugars during the mash
  • Remove proteins that can cause a chill haze to form when the beer is cooled to serving temperature
  • Darken the beer to the level required by the style though the caramelization or Maillard reaction of sugars
The least you should boil a beer to ensure sterilization is ten minutes. Typical boil times are 60-90 minutes, depending on the recipe.

The Grainfather produces a rolling boil that is designed to accomplish all the things described above. It's not as turbulent a boil as you might see from a propane burner or good kitchen stove, but it is sufficient for achieving the brewer's needs.  If you are very fanatical about getting a clear beer from The Grainfather, using gelatin finings and cold-crashing your finished beer before bottling can bring that to reality. 

Tips and Tricks

Below are my tips and tricks related to using The Grainfather throughout the brewing process:

Recipe Adjustment

Recipe adjustment is some of the art and science of brewing, and is in my opinion the thing that will take your home brewing from average to excellent.  It isn't particularly fun, and it can be time consuming.  Still, it makes a huge difference in getting the results you want from a recipe.

Imagine, for example, that you have been handed the actual recipe to one of your favorite commercial beers by a brewmaster for that brewery.  The recipe tells you that it's based on their system's 90% efficiency and 100-barrel batch size.  That's way, way out of line with The Grainfather.  You'll need to scale that recipe down to a 5-8 gallon batch, and account for the fact that a home brewer's efficiency is typically well below 90% (though home brewers can achieve high efficiencies).

In my opinion, the best way to do this is through beer recipe software.  I personally use BeerSmith as my primary recipe software, but Beer Tools Pro, QBrew, and others do exist.  Find one that you are comfortable with and can afford.  Once you've done that, each time you brew a batch, plan to take a bunch of measurements. These should include, but are not necessarily limited to:

  • Pre-boil volume:  What's left in the kettle after the sparge is finished
  • Pre-boil gravity:  After you sparge the grain and stir the wort vigorously, take a few measurements with a refractometer or hydrometer to determine the gravity of the wort
  • Post-boil volume:  How much is left in the kettle after the boil is over
  • Original gravity:  The gravity of the wort in the fermenter before yeast is added
  • Fermenter volume: How much wort is in the fermenter after pumping it out of the kettle
  • Kettle dead space: Dump the leftover material from the kettle into a measuring pitcher and determine how much wort and trub you were unable to pump out of the kettle into the fermenter

Using these measurements, you will be able to adjust the equipment profile in your recipe software to better estimate the gravity and volume you can expect at the end of the brewing process.  This will enable you to scale a recipe correctly so that you come as close as possible to the intended gravity and volume.  That will ensure that your beer looks and tastes as close as possible to what you intended.

It's worthwhile to note that you'll want to take measurements on every batch you make.  Over time you will notice patterns. For example, batches with a lot of grain may show a lower efficiency than those with a smaller amount.  When you're brewing a high-gravity batch, you will want to account for this in your recipe software so that your beer doesn't come out too weak. 

You might also change parts of your equipment and process.  Perhaps you'll begin milling your own grain and notice that gravity goes way down, or way up.  You'll want to account for that in your next batch. 

Over time, you should find that the results you get from the recipe software are very close to what you measure going into the fermenter. 

During the Mash

Here are things I've noticed about mashing in The Grainfather:
  • Mash and Sparge Calculations:  I've found that the official formula in the Grainfather manual for calculating mash and sparge water will sometimes give you more water than you need, and sometimes not enough water. This is one reason why you will want to measure your pre-boil wort quantity.  You might need to adjust your boil time to reduce the quantity of wort to hit your gravity target or add some water after the sparge to get where you need to be.
  • Wort leaking from the recirculation arm:  Sometimes the pump has trouble getting air out of the recirculating arm and has to push it through the twist on connector that holds the recirculation arm to the check valve. If you don't stick around for the first few minutes of mashing, this can result in wort leaking out of the connector and onto the floor, making a mess and potentially wasting some beer.
  • Air in the recirculation:  Similar to the above, sometimes the pump has trouble getting air out of the line, or perhaps wort is not flowing smoothly through the grain bed. This causes the pump to suck up air.  When the pump sucks in air, you'll sometimes see massive foam build-up on top of the grain bed, like this:

    I believe this probably happens when the wort can't flow as smoothly through the grain bed as it should, leaving an air pocket underneath the grain basket. The pump sucks in some of this air and blows it out into the wort on top of the grain basket, where it gradually creates foam like this. This may also reduce the mash efficiency when it happens.
  • Cleanup:  I strongly recommend that while you are waiting on the wort to reach a boil, you begin removing the spent grain from the grain basket and at least rinse the grain basket components.  This will make final cleanup a lot easier.  If you have time during the boil, I've often found it helpful to mix up some PBW and clean the grain basket and other items (like plastic bins used to store hops or grain) as I go.  That way the final cleanup consists mostly of cleaning The Grainfather kettle and wort chiller.
  • Spent Grain Disposal:  If you have cats, or a friend with cats, the large plastic containers in which some brands of cat litter are shipped will make a good short-term container for spent grain. They're water-tight, mostly-air-tight, and can hold multiple batches' worth of spent grain.  They have a built-in handle with the strength to support a full load.  The spent grain can then be composted, fed to livestock, or disposed however you see fit.
  • Pre-boil Gravity and Volume Readings:  Taking a gravity reading before the boil begins is something I strongly recommend.  Getting a volume reading is important, too.  Looking at these two figures, you can determine if the beer is going to be higher or lower in gravity or volume than you intended.  A higher gravity beer can be corrected by adding water to the kettle.  A lower-gravity beer can be corrected by boiling for a longer period of time (ideally before you add any hops if you want to hit your bitterness target) or by adding dry or liquid malt extract.  If adding malt extract, I would recommend waiting until late in the boil if it's a lighter-colored beer, as malt extract tends (in my experience) to caramelize and darken if boiled too long. I would recommend adding it in the last 10-15 minutes of the boil and taking a new gravity reading at that point to see if you're close enough to your target values.
  • pH 5.2 Stabilizer:  I've read mixed messages on whether the pH 5.2 Stabilizer product does any good during the mash process.  Given the low cost per batch, I've always chosen to use it as a sort of insurance policy.  However, I've noticed (since getting an electronic pH meter and calibrating it) that near the end of the mash my pH has dropped as low as 5.0.  This makes me question whether the product truly lives up to the hype.
  • Don't Remove the Grain Basket During the Mash:  Once I had a problem where a good amount of grain managed to spill into the kettle and outside the grain basket.  Worried that this would cause a problem, I pulled the grain basket out of the kettle and set it aside while I scooped out the offending grain.  What I didn't know in that scenario is that this allowed the grain in the basket to drop to a temperature where "kettle souring" could take place.  The finished beer had a definite, strong sour note to it.  For the style and flavor I was going for, it effectively ruined the batch.  (That said, a friend of the family loved it and took lots of it home with him.)

As I learn more, I'll be back to update this section.

During the Boil

Here are some things I've personally found useful when performing wort boils in The Grainfather:
  • Build a platform that allows for easy access to the thermal reset switch. If you're planning to include any sugars, syrups, or similar materials during the boil, I'd strongly encourage you to build a small wooden platform (mine is vaguely U shaped) to place underneath The Grainfather. This will allow you to reach underneath the device to get to the reset switch. Why is this important? Imagine that you have a boil underway. You begin adding liquid malt extract, candi syrup, candi sugar, table sugar, lactose, etc. as required by your recipe. You add it a little too fast and it accumulates on the bottom of the kettle, above the heating element. The Grainfather's thermal cut-out sensor detects a heat build-up and tries to avoid scorching the wort by tripping the switch. Boiling comes to an immediate halt. To re-arm the switch, you'll have to tilt the entire Grainfather filled with boiling wort enough to reach that switch. This introduces the risk of the kettle slipping out of your hands and dumping sticky boiling liquid all over the floor. At the very least, you'll have a mess to clean up. Worst case, you may dump the boiling wort all over yourself and get severely burned. A simple platform can prevent that.  This is a part of The Grainfather's design that I don't understand. In my opinion the reset switch ought to be easily accessible from the side of the unit. Having to lift or tilt it is simply inviting a catastrophe.
  • If you trip the thermal cut-out, clean the burner area before hitting the reset switch. If the thermal cut-out has been tripped, this invariably means there is material accumulated on the bottom of the kettle where the heating element resides. Use a mash paddle or long spoon to scrape away as much of this accumulated material as possible. If you had just stirred in a syrup or sugar, make sure to stir the wort thoroughly. If you don't do this before hitting the reset switch, it will trip again in a few seconds.
  • Early on, use hops bags and spice bags. If you reach the end of the boil time and find that your kettle includes more wort than you wanted, and at a lower gravity than expected, you'll need to extend the boil to concentrate the wort tot he appropriate gravity. If you tossed in hops and spices without bags, extending the boil means you're going to get a more bitter beer with a different hops and/or spice flavor profile than you expected. Placing the hops and spices in bags (and perhaps even attaching food-safe string to the bags) will allow you to remove those and continue the boil without over-bittering the beer. I currently use a hop spider and bags from Brew Bag to keep my hops, spices, fruits, etc. out of the kettle itself. This helps prevent tripping the thermal cut-out switch and keeps me from clogging the pump filter. (One recipe I made where I accidentally dropped the hops pellets directly in the kettle resulted in a very clogged filter that could barely pump the wort into the fermenter at the end of the boil.)  Because these bags reduce the yield from hops, you may want to adjust your bittering upward by about 10% (in IBUs) to account for that.
  • Avoid boil-over. If you're routinely brewing batches of five gallons or less, the height of The Grainfather's kettle alone will probably prevent boil-over. Still, there are things you can do to ensure that. Sticking around during the first 10 minutes or so of the boil and stirring in any foam you see will do the trick. If that's not feasible, a few drops of Fermcap S at the first sign of foaming will eliminate it. Spraying cold water on the foam will also break it up.  There is also a device on the market called The Brewcolator which works well to prevent boil-over and can increase boil-off as well. I've used all of these techniques effectively.
Post-Boil and Fermentation

Things I've learned about the device and results after the boil:

  • Hops, Spices, etc., and the Kettle Filter:  Although the official Grainfather videos show hops pellets being dropped right into the kettle during the boil, my experience doing that (by accident in one batch) has not been positive.  I've found that as little as an ounce of hops pellets in the kettle has been enough to cover the filter and reduce the flow of wort out of the pump to a trickle. For that reason, I recommend getting a hop spider or hop bags and using those for your hop additions instead of direct kettle addition.  It takes the pump quite a while to push the wort through the counter flow chiller and into the fermenter under good conditions, and when "gunked up" with hops and spices, it takes even longer.  I've even had cases where the flow pretty much stopped completely.  This may be better (or worse) with whole hops vs. pellets, but I haven't used a lot of whole hops so I can't really say.
  • Counter Flow Chiller:  I generally attach this at the start of the boil.  Around 5 minutes from the end of the boil, I'll turn on the pump and run the boiling wort through the chiller (without turning on the cold water supply) to sterilize the inside of the chiller. At the end of the boil I'll turn off the pump and turn the cold water supply on.  This cools the sterilized chiller back down to tap water temperature again after a few minutes.  If you don't do this cooling step before turning the pump back on and pumping your wort into the fermenter, you may find (as I have) that the temperature of the wort in the fermenter will be on the high side - perhaps as high as 80-85F.  If you cool the chiller down first, the temperature under the same circumstances can be as low as 65-68F.
  • Cold water connector:  My cold water connector has pretty much always leaked from day one. I tried using a clamp to hold the hose to the barb. That reduced the leakage but never really stopped it.  I ended up breaking the connector trying to tighten it enough to stop the dripping. In the end, replacing it with a new connector from an old immersion chiller did the trick.  You'll need one that has a 3/8" hose barb on one end, a garden hose thread on the other (if using a garden hose spigot), and a small stainless steel band clamp.
  • Good to the Last Drop:  This is one of those "your experience may differ" things, but I've found that it's worthwhile to tilt the kettle during the pumping of wort to the fermenter. This allows the pump to extract as much wort as possible from the kettle at the end of the boil.  If you're using hops bags (or a hop spider) there won't be a lot of trub in the kettle to pull into the fermenter. Even if you do, there is some research to suggest that this will possibly improve the flavor of the finished beer anyway.  I'm able to reduce the leftover wort in the kettle at the end of a brew to about a quart, which means more beer to bottle and share at the end.  If you try this and your experience differs, do what works for you.
  • Aeration:  If you position the cold wort line high enough in your fermenter when pumping wort into it from The Grainfather, the action of the wort falling into the bottom of the fermenter will naturally aerate it as it goes. For most low-to-medium-gravity brews, this should be sufficient aeration (at least in my experience) to eliminate the need for any significant sloshing afterward. For higher-gravity brews, I've found that an air stone and pure oxygen does the trick... though I have successfully done several high-gravity batches without using oxygen.  This is something you'll want to experiment with.
  • Chill Haze:  In my experience so far, virtually every batch I've made with The Grainfather has had chill haze.  For batches shared with family and friends, I don't worry too much about this.  For batches going into competition, where the style doesn't benefit from haze, I have found that using gelatin finings after fermentation has stopped and chilling the wort before bottling helps a lot.  If possible, an extended refrigeration period before competition will help as well, as chill haze will tend to settle out after a long enough period at refrigeration temperatures.


Popular posts from this blog

Things I've Learned Brewing with The Grainfather, Part 2


Yellow Label Angel Yeast vs. Typical Brewing Yeast


Brewing with The Grainfather, Part 3 - Cleaning and Overall Thoughts
