Originally Posted by rph33
Hmm, all I've ever heard / experienced is that basically all quality extract yields the exact same amount of fermentables per gallon, in about 44 OG points per pound in one gallon of water. I've never heard about extract actually yielding a LESSER fermentable wort! But I could be totally wrong about that, maybe there's some advanced stuff about extract that I don't know.
Anyone chime in on this?
As ghpeel states above, Extract can in fact be helped to achieve higher attentions (lower f.g.) by simply adding some base malt to the extract in the mash. Extract is essentially the result of malting at about 155 deg F to be a jack of all trades with modest body and sweetness. This is too high for a bone dry brew like duvel but you can raise (though never lower) the percent fermentable sugars by adding some base malt. Base malts have high concentrations of malting enzymes - enough to share. if you add them to the extract, they will help break the extract down further in the mash. Dont look for specialty grains to help out. Most don't even have enough enzymes to malt themselves, let alone the extract. There are calculators Ive seen online for estimating enzyme content of grains by type. By malting the extract at low mashing temperatures (148 deg F) with a base pilsner malt (say 30 - 50%). the base malt will break the large carbohydrates down into more fermentable simple sugars. The more malt enzyme, the faster the process. Less malt enzyme means you should let it mash longer. I mash my 100% pilsner gain at 148 for 90 - 120 minutes.
Also note that Duvel uses large amounts of pure sugar (beet or cane), which are both 100% fermentable. This will help for the averaged low f.g. It will not make you final brew sweet as someone above feared it might. You will need to experiment with the grains you have available to find a mash schedule that works for you for this beer.
Duvel is a devil of a beer to replicate. It lives up to its name, and is a a puzzler's puzzle. Ive made 5 attempts now, all grain without adding sugar. I found that adding any carapils makes the color too dark and now use 100% pilsner 19 lbs/5 gallon batch, though I vary the percentages of belgian and domestic that I mix. The trick to this beer is not body anyway but high attenuation, which the carapils will mess up anyway.
All of my attempts so far have been too high fg. Too sweet. Ive given up with the 100% grain and the next batch will involve high quantities of sugar. At least now Im confident that I can consistently achive the same final gravity. my advice is experiment, if you have too high fg, add beano. I just added it for the first time to Batch 4 which Ive had in the secondary for about 4 months now. It finished about 1.015. I added two crushed tabs of beano and a day after, it had a small layer of bubbles. Now 4 days alter it has a full head of foam as it ferments the newly broken down sugars. Hey, the batch would have made a great Strong Golden, but it would have been no Duvel, so it had already failed the purpose it was created for. Ive got nothing to lose right? And it looks like I added a new trick to my brewers tool belt.