Wednesday 15 January 2014

Brewing an Alpine Duet clone - Version 2.0

Two years ago, I returned to brewing after an almost two-month absence due to an unexpected surgery. The previous fall, I had taken my first beer trip to San Diego, and was (of course) blown away by the beers that were pouring there, mostly from local breweries. My favorite beer of the trip was Duet, an excellent, low-IBU (~45) American IPA from Alpine Beer Company. I was lucky enough to have the beer on tap at a beer bar in the city, and I even found a bottle to take home... at the time, I didn't realize quite HOW lucky I had been, because when I went back in September of 2013, I couldn't find Duet anywhere!

Picture courtesy of
Well, I figured my first homebrew after my short hiatus should be a clone attempt of Duet. All the info on that beer (including an email from Pat, Alpine's owner/brewer) is here. After a couple months of blogging - with very few pageviews - my post on this clone attempt finally started bringing in a few people. Two years later, it's still by far the most-viewed post on this blog in terms of homebrew recipes, and more people have found this blog through Googling the words "Alpine Duet clone" than any other search.

But, what did I think of the beer? The original tasting notes are posted here; originally, I was disappointed with the results. Of course, I wasn't able to compare it to the real thing, but I felt that the hop punch just wasn't as big as I was expecting... or hoping, anyway. However, over the next week or two, the flavors really started coming together, and in the end it came out as a really tasty beer. I submitted it to the Canadian NHC 1st-round qualifier (back in the good ol' days when we had one), and won a Bronze medal in the IPA category. I brewed a different IPA for the final round of the NHC, because I felt the Duet clone wouldn't be fresh enough by then; unfortunately, the beer I ended up sending in was inferior to the original.

Just some of the trub filtered out of the wort post-boil.
Sooo... long story short, I've always wanted to brew this beer again, with a few minor changes to see if I could make something even better. Finally, that day has come! The recipe I decided on really isn't TOO different from my original; more hops of course, but it's still equal amounts of Amarillo and Simcoe, as made clear by Alpine. If you compare the hop schedule to my last attempt, this recipe drops the 5 min addition, but doubles the flameout addition (cut in two, with a hop steep for 20 minutes, and the other half added when I started chilling). The dry-hop now has two additions of 1.5 oz of each hop, effectively doubling the last recipe's dry-hop as well.

As for the grist, again, pretty similar to last time: a slightly higher percentage of 2-row, with the Wheat malt, Carapils, Acid malt and table sugar all being equal to before. The only big change was that I dropped the Victory malt, and subbed with Crystal 30 L (a bit smaller amount than the Victory). Why? Well, the original suggestion from Pat included "Amber malt"; the Amber malt at my LHBS is quite dark, so I knew he couldn't mean this. Some people interchange the term Amber for Victory, which is why I originally chose Victory. However, recently I came across a thread at where someone noted that when they've toured the brewery, they've come across labelled sacks of CaraAmber, and not Amber or Victory. Makes sense... unfortunately, I don't have access to CaraAmber, and Crystal 30 L was the closest substitute.

I also adjusted the water chemistry slightly this time around. Just a bit of calcium chloride and Gypsum, which is what I've been doing for most of my hoppy beers lately. Nothing severe, just bumping up the calcium, sulfate, and chloride levels for taste purposes; the mash pH also comes down a bit as a result (also from the addition of the Acid malt to the mash). Same yeast as before, too, clean and neutral US-05 Safale.

Hoping for great results like last time... but, hoppier. Looking over the recipe, it occurs to me how very close it is to the Maine Beer Co. MO clone I brewed last week. Similar grist, almost-identical hop schedule, with Amarillo replacing Falconer's Flight. Should be pouring both beers at about the same time... and I MAY even have kegging equipment here in time as well, which I'm hoping will further allow the hop flavors to really pop. No trips to California planned; however, a couple of people have mentioned that they'd be willing to send some Duet my way, so hoping that pans out!

Recipe targets: (5.5 gallons, 72% efficiency) OG 1.065, FG ~1.012, IBU ~35 (calculated; actual closer to 45-50), SRM ~6.5, ABV ~7%


4.65 kg (77.4%) Canadian 2-row
454 g (7.6%) Wheat malt
340 g (5.7%) Crystal 30 L
227 g (3.8%) Carapils
113 g (1.9%) Acid malt

Magnum - 8 g (10.8% AA) @ 60 min
Amarillo - 28 g (8% AA) @ 10 min
Simcoe - 28 g (12% AA) @ 10 min
Amarillo, Simcoe - 42 g each @ flameout, 20-minute hop steep
Amarillo, Simcoe - 42 g each when started chiller
Amarillo, Simcoe - 42 g each dry-hop for 4 days
Amarillo, Simcoe - 42 g each dry-hop for 3 more days

Misc.: 1/2 tab Irish moss @ 5 min

Yeast: US-05, 1 package, re-hydrated

Water: Fredericton city water, carbon-filtered; 6 g Gypsum, 4 g calcium chloride added to the mash

- Brewed on January 13th, 2014, by myself. 60-minute mash with 17.85 L of strike water, mashed in at target temp of 148 F. Sparged with ~4.75 gallons of 168 F water for final volume of slightly over 6.75 gallons

- SG on target of 1.049. 60-minute boil. Final volume ~5.75 gallons. Chilled down to 62 F, then poured/filtered (lots of hop sludge, as seen in picture) into Better Bottle. OG a bit high at 1.060 (with sugar addition later, final OG will be 1.066). Aerated with 90 seconds of pure O2, pitched rehydrated yeast. Placed BB in laundry room, ambient temp 67 F. 

- 14/1/14 - 18/1/14 - Lots of active fermentation over this period; the temp never got above 70 F. 

- 28/1/14 - Racked to secondary carboy after purging with CO2. Added 1st dry-hop addition, and purged with CO2 again. FG 1.010.

- 31/1/14 - Second dry-hop addition.

- 4/2/14 - Bottled ~1 gallon with 25 g table sugar, aiming for 2.5 vol CO2. Kegged the rest of the beer, set in temperature-controlled room at 46 F, and set PSI to 14.

- 12/3/14 - Tasting notes... great IPA, lots of tropical fruit hop aromas and flavors... but still needs a bit more hop punch to approach the real thing. 


  1. Great write up! I'm on the other side of the world but I dream of going to Alpine one day and in the meantime I think I'll need to give this recipe a try. One thing though, I think you were right to go with Victory the first time. CaraAmber is unhelpfully named because it's more like Victory or biscuit of some kind than crystal.

    1. Thanks!

      Honestly, it was a tough call. When looking up substitutes for CaraAmber online, seems like half the people say Victory or Biscuit, the other half say a Crystal malt. I guess I figured I'd just go with something different than last time, and will make a final decision after I give this a try, for next time.

      Need to get my hands on some more Duet, though, even though the best source would obviously be on tap or in a growler.

    2. Yeah, I've seen those substitution charts. I guess people get confused because of the cara- but when you see & taste it, it's clearly not a crystal malt. Either way, it should still be a delicious beer. I'm looking forward to the review!

    3. Hope this doesn't come out too "Crystally"... luckily it's only the 30 L, and less than 6% of the total grist, so it should be ok. I'm definitely more a fan of the dry IPAs!

    4. I'm totally with you there. I think it'll be fine with such light crystal.

  2. Well, how did it turn out? I'm looking at giving it a try.

    1. I'll be posting the results of my Maine Beer Co. MO clone any day now, followed shortly by the Duet 2.0. Shouldn't be long.

    2. FYI - Somebody has posted an email from Pat where he talks about his hop schedule, the amount he uses for dry hopping i believe works out at an ounce a gallon

    3. Nice, thanks for the link! Looks like he's talking about Nelson, but still good to know. And yes, if they dry hop Duet at the same rate of about 1 oz/gallon, I wouldn't have been too far off, just a bit over.