Tag Archives: home malting

Tasting: Popcorn Malt Hefe-Maisbier

Popcorn Malt Hefe-MaizenI have been on hiatus now for few months, not just from blogging but also brewing in general. I had some health problems flare up earlier in the year and couldn’t drink much beer, and had little energy for brewing. But in any case, I had the few bottles I ended up getting out of this batch to taste.

The brewing process was a bit of a disaster, and fermentation got stuck around 1.020. It also looks like I did some things wrong while malting. I attempted to soak the corn in a dilute lye solution, as had been recommended in an African sorghum malting guide. This is supposed to help disinfect the grains a bit so that the high-temperature (relatively speaking) malting process isn’t thwarted by microbial growth. Dilute as it was, it ended up  contributing a ton of flavor. I think it soaked in there for less than an hour, since it was already changing the color and apparently changed the flavor. In short, here’s the problem: soaking (and boiling) corn in alkaline solution makes nixtamal, which is dried and ground into masa flour for making tortillas and such. Even though it was short and never boiled, the beer ended up tasting weirdly like tortilla chips. That this was at all drinkable was a miracle.

I realize it’s a bit odd to complain about a corn beer tasting too much like corn, but this is really the wrong kind of corn flavor. My previous corn beer had no discernible corniness. I think if I could go back and referment that wort as a weissbier it would have worked great.

Appearance: The color is nice, with a slight chill haze. The yeast, surprisingly, mostly dropped out. Attempting to pour the yeast from the bottle resulted in unsightly clumps instead of the pleasant haze you’d expect.

The head was pretty thin. I suppose it’s consistent with a highly carbonated, low gravity beer. It doesn’t seem like the corn (popcorn, specifically) lacks the necessary protein, since there is a ton of it in the boil. The bad malting this time may have hurt this more by not breaking them down into the right kinds of foam-positive proteins. Definitely a disappointment, since my last corn beer produced a very smooth head.

There was some slight lacing, but even with thorough manual cleaning of my beer glasses with the appropriate agents (baking soda, mostly) I don’t seem to get enough out of any beer, not just my homebrew.

Aroma: There is very little clove in the aroma. Actually, there wasn’t much aroma to speak of. Occasionally the tortilla chip aroma floated off but it wasn’t strong.

I sort of suspected it was DMS for a bit, since there was a lot produced during the mash and sparge (intense cooked vegetable flavor), but it wasn’t super consistent with the description of low levels of DMS. Plus, the boil was a full two hours.

Also of note: while last time my kitchen reeked of corn after the process, this time I didn’t notice it as much. I have no idea if that’s important or not.

Taste: The vague tortilla chip flavor is quite strong, and takes over the muted clove character. Moving it around on the tongue, the tortilla flavor dissipates and the clove comes out more. Ultimately, it is very, very bland, with a very slight sweetness from the unfermented sugars. The resultant low alcohol level and complete lack of body make this very boring indeed. High carbonation helped, but it was no magic fix.

Since the unfermented sugars contributed only a slight sweetness, I’m going to guess it was not a true stuck fermentation, per se, but rather incomplete conversion in the mash.

Mouthfeel: Thin. The high carbonation also helped here. I think it could have been even more effervescent. My carbonation calculation was for 3 volumes, I believe, but I think it was a little low.

Overall: A total disappointment. I suppose it’s not a complete failure since it was actually drinkable, a low bar as that may be. Once I get my brewing stuff back on track I’ll have to retry with the popcorn I have left over. Next time there will be no soaking treatment beyond water.

Home Malting Tips

Malting seems to be the one aspect of brewing that most homebrewers are very content to leave to the professionals. Lots of people grown their own hops, and an increasing number of people seem to be taking up yeast culturing. But judging by the dearth of information available online, malting just isn’t that popular.

I do wonder how much of that is just due to gross misinformation about the process. Sure enough, even the few resources out there are riddled with errors sure to doom your batch unless you are rather lucky. I tried to follow some of these and ended up with little to show for it. But now, having made a few successful batches, I hope I can clear some things up. These are the main things that put me off or messed up in the past.

Much of this information comes from three very good sources: Graham Anderson’s article in the Jan-Feb. ’13 issue of BYO, Andrew Lavery’s guide for malting gluten-free grains, and the blog Brewing Beer the Hard Way (where he goes the much further step of growing the grains himself).

Technical aspects and equipment

Malting can be as technical as you want it to be. You can track and control moisture levels and temperatures, or you can be a little more relaxed about it. In my case, I’ve used my fermentation fridge for malting cold-climate grains like wheat (I haven’t done barley yet) but used room temperature for warmer climate grains like popcorn. I haven’t kept track of moisture content, and that may explain some of my undermodified batches that seemed to dry out. However, even those batches have worked out OK for the most part.

Note that I am not saying moisture content and temperature don’t matter. They do, quite significantly. But winging it is often enough when doing this just for fun.

You can go all-out with dedicated equipment, but simple things work, too. I use my apartment’s oven (which has a helpful but not necessary “Keep Warm” setting) as a kiln, which should likewise work for most people. The sprouting bed consists of a large, clean garbage bag on the floor, optionally on a towel to prevent the rather annoying noise if you have wood floors. I use another to loosely cover it up (edit: this may be a bad idea due to condensation and possible mold growth). I have also used baking trays. The only piece of equipment I’ve made especially for it is a rather shoddy oast/tray of folded-over aluminum window screen material. It is flimsy but does the job.

Cleaning and soaking

Graham Anderson’s article suggested repeatedly rinsing out grains until the water runs clear. This seems to work out well. In addition, letting them absorb water without forcing them down is a good idea since some broken grains will float. You definitely don’t want broken grains in your batch, if for nothing else than that they are prone to molding and won’t sprout.

The soaking water should not have chlorine in it. According to at least one malting textbook, it’ll lead to bad flavors in the finished beer, much like brewing with chlorinated water would. I suspect rinsing with chlorinated water would be OK since not much would seep in, but I haven’t tested that yet.

Soaking needs to be broken up so that the grain can breathe a little. Graham’s article suggested 8 hour soaks followed by 8 hour air rests. Three soaks seems to work for wheat and barley, but popcorn at least seems to need four. I rinse the grains before and after each soak. This may well be overkill, but at this scale it is not a problem. It may be possible to use an aeration pump in the soaking water instead of the air rests, but the water should still be changed due to bacterial growth. This is something I am experimenting with right now.

Drying and kilning

This is likely the most important thing that is often wrong, based on what I had read. I certainly had it wrong myself. When malting at home, drying and kilning should be entirely separate processes. Drying under heat is likely to damage your grain’s enzymes since home ovens don’t produce the sort of low, steady temperatures and ventilation necessary for drying. A fan blowing over the grain bed does a great job in a few days (another tip I got from Graham’s article).

Again, grains should only be kilned once they are thoroughly dry. Once the grain weighs less than what I started with, I move part of it to the shoddy oast in the oven where I hold a low temperature (180-200F) with the door cracked open. If your home oven doesn’t go that low, a toaster oven might work (this is another solution using a hot plate in the oven instead of the built-in elements). I kiln for usually an hour to three hours depending on how the aroma and flavor develops.

That last bit is the key: without kilning, malt simply won’t taste or smell like malt. It’ll be extremely pale and likely won’t convert well on its own due to high mash pH, despite its high enzyme content. Sometimes there is a grassy smell, especially if the sprouts were exposed to light, that kilning also seems to take care of. A long boil might do the same.

I let the kilned grains rest for a month or so before brewing. This seems to soften up the flavor a bit, in a good way.


I’m not suggesting that home malting is better in any way than buying it off the shelf. It is likely inferior in pretty much every way, especially predictability and consistency (that’s where being technical really helps). However, malting and brewing with the malts has been the most fun I’ve had brewing since I started doing yeast culturing in earnest. A rich, sweet wort is a lot more impressive when you know the bland, tough and starchy grains that you started with.

Searching through forums, I’ve seen quite a few “why would you want to do that?” responses to people who asked. Frankly, that’s just moronic. You could easily say the same thing about growing hops or yeast, or even about homebrewing in general. These days, there are plenty of good beers at the supermarket, so why bother? Right? Right?

I might at some point post a complete guide of how I do it. In any case, the referenced articles should provide enough of an idea how to do this yourself.

Popcorn Malt Hefe-Maisbier

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I first brewed a beer using nothing but malted popcorn this past summer. It was mostly successful (and turned out to be my most popular post ever) but some fermentation troubles knocked it down significantly. Since then I have been wanting to try again. I malted six pounds of popcorn in November, and finally brewed with it this weekend.

While the popcorn ale would have been good if not for the acetaldehyde, this time I decided to try for a more yeast-driven style. I figured something in the style of a hefe-weizen would work well. The generally high protein content of the popcorn plus the fact that a good amount of the grains never sprouted might help it work like a high-percentage wheat mash would.

After picking the style, I kilned the fan-dried malt to different points in amounts I thought would work. I went with more kilned malt this time due to the lack of, well, malty flavors from the air-dried malt. My reason for not kilning the entire batch was to hopefully preserve more of the enzymes, especially lower-temperature enzymes that are more easily damaged during the kilning process. This mash schedule (detailed here) incorporates a beta-glucan rest and a protein rest, so having those enzymes actually present would be good. I also made some darker kilned malt and another attempt at crystal malt for flavor, hoping it’d counteract the dilution by the wind malt. Indeed, the wort was much richer in flavor this time.

While the beta-glucan rest may not be necessary for corn, it doesn’t seem to hurt. Additionally, the rest is in the temperature range for a ferulic acid rest. I can’t say I know if that’s applicable to corn, either, but again, it doesn’t seem to do any harm beyond taking up a few minutes. I definitely kept the protein rest, especially since there was a good amount of effectively unmalted grain in the grist. This may actually be a good thing for head retention.

The majority of the brew day was straightforward. A notable exception was my total screw-up with pH correction. I got a pH meter for Christmas and planned for pH corrections using a water calculator. The calculator predicted the mash pH (10 minutes in) without acid right on. I rather stupidly proceeded to add the entire predicted amount of phosphoric acid at once, promptly dropping the pH from 5.7 to 4.8 in a cooled sample. After the initial panic, I stirred more and measured again. It’d gone up to just under 5.0. I then added some baking soda to bring up the pH. This was actually in line with the “Balanced Profile” on the Brewer’s Friend calculator, although I was not planning on adding it and the acid calculation did not include it. At the beginning of the protein rest I was up to 5.2 at room temperature. That’s a little low (I was going for 5.4) but still within the acceptable range. Saccharification seemed to go OK. I didn’t add any amylase enzymes this time.

The mash steps were not calculated for temperature with the exception of the beta-glucan and protein rests. I used direct heat on the stove instead and used volumes that worked comfortably in my 5 gallon kettle.

Here’s the usual verbose write-up:

Hefe-Maisbier, 2 gallons


  • 2.5 lbs. pale popcorn malt, kilned at 190F for 1 hour
  • 2 lbs. wind popcorn malt (unkilned dried malt)
  • 8 oz. Munich-ish popcorn malt, 250F for 1 hour
  • 3 oz. medium crystal popcorn malt


  • 0.5 oz. Tettnanger, 3.8% AA @ 60 min.

Water: Carbon-filtered DC tap water with salt additions (see notes)

Yeast: Danstar Munich, rehydrated, about 5g. I was going to grow WY3068 from my bank in sorghum wort (so that it’s gluten-free), but had to reschedule the brew and didn’t have time.

Full process:

  • Collected 5 gallons of filtered water and added 2g calcium chloride, 1g gypsum and 0.1g potassium metabisulfite.
  • Crushed malt with a Corona knockoff mill. This is easily the worst part of the brewday.
  • Mashed in with 6.5 quarts at 109F. Settled at 104F. Rest for 10 minutes.
  • Measured (cooled) pH at 5.7. Added full calculated amount, 17mL 10% phosphoric acid; pH went down below 5. Ended up adding 0.6g baking soda to bring it back up to 5.2. The calculated target after acid addition was 5.4.
  • Rested another 15 minutes with occasional stirring.
  • Added 1.5 qts. of boiling water to bring up to 122F. Rested for 25 minutes with no stirring.
  • Siphoned 0.8 gallons off the top into a gallon jug.
  • Added 2 qts. boiling water plus direct heat to get to 165F. This converts some of the starch into dextrins so that the boil is thinner. Raising the temperature took 10 minutes, rested at 165F for 20 minutes. The mash thickened significantly around 160F, the upper range of gelatinization for corn starch, before thinning again from alpha-amylase activity.
  • Brought up to a boil with direct heat and boil for 5 minutes. Covered and let it cool down naturally. The mash was very thick as the grain further gelatinized and absorbed water without any enzyme activity.
  • Poured enzyme liquid back on. Added a further quart of cold water and adjusted temperature to 150F.
  • Rested at 150F for 75 minutes. The pH was 5.3 at this point. I did not bother to check starch conversion this time since the iodine-positive mash last time didn’t seem to cause any problems. The wort was very sweet and thinned out again so it seemed OK. Edit: I tested some tail runnings I saved a few days later. Looked OK–perhaps a little bit of a reaction. Edit 2: Hydrometer sample was slightly positive as well.
  • Raised to 165F for 15 minutes for mash-out.
  • Transferred about half of the grain and liquid into my 2 gallon lauter tun. The whole amount would not fit so I had to do it in batches. Vorlauf and lauter initially went OK without any rice hulls or other aids. Drained about 1 gallon into the boil kettle.
  • Added the other half of the grain and more of the liquid. This caused the lauter to get stuck. After messing with it for a bit I abandoned the tun and went with a fine mesh bag.
  • Added 3mL 10% phosphoric acid to the remaining water (about 2.5 gallons) to bring the pH down to just under 6.0. Heated to 165F and dunked the bag in. Stirred and rested for 15 minutes.
  • Collected a total of 3.8 gallons at 1.025.
  • Boiled for an hour without hops. Added 2 drops of Fermcap as the hot break started to form.
  • Added 0.5 oz of Tettnanger (which didn’t smell great once boiled, despite being a new pack. Glad it was a bittering addition.) and boiled for another 50 minutes. Added 1/4 tsp. Wyeast nutrient, 1/4 tsp. Irish moss and copper immersion chiller and boiled another 10 minutes.
  • Chilled to 58F. Poured entire kettle into the fermenter, about 2.1 gallons. This puts the gravity around 1.045, although I did not measure it. This included a massive amount of protein break that eventually settled (phew). I will hopefully get at least a clean gallon out of it.
  • After about an hour, oxygenated for 10 seconds with pure O2 and pitched yeast. I rehydrated the whole pack and poured half of it into the fermenter.
  • Ferment at 16C (~62F). Took about 24 hours to show signs.
  • Update: Took a hydrometer reading two weeks in. The yeast had almost totally dropped out. It seemed to be stuck at 1.020–I can’t tell if it’s the wort or the yeast. It also does not taste very good. Thin, watery, tart (in a bad way, thanks to the crazy acid addition) with only a little of the desired yeast character. It’s possibly slightly oxidized, too. Not exactly what I wanted. I’m leaving it another week or two before bottling, now with the temperature raised to 18C. I guess now I’m just hoping that carbonation does some sort of miracle to save this one.
  • Update, 1/27: Bottled 1 gallon of it with 32g table sugar for about 3.2 vols. of CO2. Went in PET bottles due to worries about the high FG and high carbonation in general. The gravity had moved slightly since last check to about 1.018 or so, corrected for temperature. I added another yeast to what was left in the fermenter to see if it was the yeast or the wort that led it to end higher than expected. Given that it does not taste very good I’m not too worried about what happens at this point.

100% Popcorn Malt Ale – Tasting

100% Popcorn AleMy excitement about this beer, which was probably very evident from my original post on it, was tamed a bit when I went to bottle and measured the FG. After correction, it was about 1.001. What was supposed to be a 4% ABV beer turned into about 5.3%, and with such a low FG I feared it would be very thin and/or a little boozy.

I would imagine this low FG is due to the extended mash, specifically the ill-advised extra 1 hour rest with fresh amylase at 63C/145F as was recommended in the instructions for the amylase formula. This particular amylase formula has beta-amylase, but being of fungal or bacterial origin I wasn’t (and still am not) sure it has the same temperature range as grain amylase. So, I went with the optimal temperature given, which in retrospect probably meant the optimal temperature for converting all starch and dextrins into fermentable sugar.

Fortunately, it looks like it wasn’t that big of a problem. Notes follow.

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100% Malted Popcorn Ale

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It’s time for something a little different and not really yeast-related. I recently decided to try home malting again after two unsuccessful previous attempts. The BYO article earlier this year provided the inspiration as well as the missing information I needed to do it easily and correctly. After a successful, though undermodified, batch of wheat malt, I decided to repeat my first experiment: malting run-of-the-mill popcorn from the grocery store. I did this two years ago, before I started brewing at all, so I knew very little about how it worked in practice and ended up throwing it out before I did anything with it.

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