I was flipping through BrewDog's recently released catalog of their recipes and there are a couple I'd like to have a go at.

I was originally going to ask how to convert some of the recipes to extract but then did some reading about the brew-in-a-bag method.

So some quick questions with an example in mind:

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In this recipe, the grain bill calls for Extra Pale - Maris Otter, Caramalt and Munich.

1) For the BIAB method - Do I simply add all the grain to a bag, insert into my kettle and hold at 65c / 69c for an hour?

2) Is it possible to use less water in the boil rather than the full volume? e.g Have ~17.5L boil and top up with cold water at the end?

  • Do you have conditions to perform a lager fermentation?
    – Mołot
    Commented Feb 29, 2016 at 17:01
  • Yeah I think so, we recently built a keezer with its own temp control so keeping it around 10c should be a breeze.
    – TomSelleck
    Commented Feb 29, 2016 at 17:46
  • Note that they call for 16C, when yeast manufacturer calls for 9-13C. Your call. Personally I'd go with wyeast and 10C if i could... but probably my clone wouldn't be perfect.
    – Mołot
    Commented Feb 29, 2016 at 17:52
  • I think that 16c is a mistake, in the bottom right under "Brewer's Tip" it mentions that it should be close to 12C or below.
    – TomSelleck
    Commented Feb 29, 2016 at 19:49
  • 1
    Keep in mind when thinking about temps they probably copied their temp into this recipe. Going from a much larger fermentor to 5 gallons would require a lower temp than they report. As Molot said 10C is probably a better choice. The larger format fermentor creates more hydrostatic pressure on the yeast which suppresses ester formation. A warmer ferment (16C) would produce less esters than a ferment of 5 gallons at 16C as a result.
    – brewchez
    Commented Mar 1, 2016 at 19:53

1 Answer 1


Yes, you do simply put all grain (crushed!) in a bag. That's the point.

However Brewdog's catalog calls for fly sparging, something you simply won't do. With fly sparging, your extraction efficiency can be about 80%. Yesterday I hit 95% (again, against my plan, and I really hate it, but that's just btw). Even 90% should be perfectly doable. Without sparge, best reported results I have seen was at 70%. Usually worse. This means you need 20-25 percent more grain than a standard recipe. If you will just use bag without adjusting grain bill, your beer would turn out weak, watery, and tasteless compared to original. For first try, keep some DME at hand, to correct your wort if needed. Once you know your efficiency, you can calculate exact amount of grain to hit OG you need.

Using less water for boil is possible, but don't do it if you can avoid it. Full volume boil will allow you to extract hops just the way they did it. And that's the way if you want to brew a perfect clone. Less water can cause worse extraction of alpha acids. Also, it can promote maillard reactions - something you might want sometimes, but definitely does not look like planned in this recipe. Oh, and if you have to do a partial boil, top it with well boiled water, not just cold tap one.

  • Good call with the DME, I might pick up a couple of KG to whip up a starter as well. I really wanted to do a partial boil as the copper chiller I have is useless / takes hours to cool. I've taken to putting 3/4 Kg of Ice into partial boil's to top up to my desired batch size. Its very effective at reducing the temp. to ~20c almost instantly..
    – TomSelleck
    Commented Feb 29, 2016 at 17:51
  • @Tomcelic whatever is sterile. But keep hop utilization and maillard reactions in mind. For not-so-hoppy, not-so-strong beer it shouldn't be a problem. I hope. Still, would try to avoid that.
    – Mołot
    Commented Feb 29, 2016 at 17:53
  • Note that you can double-crush your grains to improve your efficiency with BIAB. I do a fairly fine crush (my mill is set to 0.035") on my grains and I usually get between 75 and 80% efficiency. Since you don't have to worry about a stuck sparge you can grind pretty fine. Definitely try to do a full-volume mash, though.
    – TMN
    Commented Mar 11, 2016 at 16:55
  • Howdy - quick update / question: I followed the steps to do a full volume / all grain batch. Everything went smoothly (used 25% more grain etc.) but went I took the O.G is was 20 points over (~0.0.65), eek! I diluted with water to get about 25L @ 0.045 instead of 20L @ 0.065. Is this likely to the mash being more efficient than expected, using too much grain or the mash being too hot? Bonus question - I need to brew 40L of ale in the next few days but only have enough room to mash / boil about 25L of liquid.. any ideas how to best handle this situation?
    – TomSelleck
    Commented Mar 21, 2016 at 11:11
  • @Tomcelic Ask this as a new question, please. Actually, two. Also, try to calculate your efficiency.
    – Mołot
    Commented Mar 21, 2016 at 11:12

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