This is one of about six threads I've read on a variety of forums about bottling with DME. So far, I cannot elicit one good reason to do it, and several not to. I haven't seen it mentioned here, but DME is also alleged to actually form a krausen in the bottle neck, while dextrose doesn't.
If the size of the bubbles is an issue, I fail to see how one sugar or another is going to induce yeast to want to produce what, different CO2? This just doesn't make sense given any science I know. I think a creamier, foamier head is likely to be a function of other things in the beer, perhaps proteins or other molecules resident in the brew. Then there's the whole nitrogen thing, which is terra incognita to me, and likely to remain so......
I heard something on Basic brewing yesterday (and I am going to do a write up for my bottling thread) talking about this. The current show is about alternative priming sugars.
The guest, who by the way, although he was from Michigan, and is supposedly a minister and an expert on priming
is not me, though it was freaky to hear is bio, made a couple comments about dme and krausening.
Evidently the reason folks used both methods traditionally to prime their beer is simple, because DME is made with
malt, and therefore was allowed under the Reinheitsgebot, the German Purity Law. Whereas sugar, whether it is table or corn,
is an adjunct. So that's one of the main reasons why using DME, mashing fresh wort, or saving some of the original wort and krausening with it are still popular bottling options, though practiced less and less these days.
As to the fact that we often see krausens when priming with DME, I, and many first time brewers who start panic threads about it, have seen the elusive bottle krausen on beers primed with corn sugar as well. I think it is more a factor of the yeast being used, and proteins in the beer, than necessarily being JUST that it was primed with DME.
Now as to the second question, being about bubble size, I can't really speak on the specifics of DME priming and bubble sizes in the head. I only primed with DME once and that was over 5 years ago and I don't recall specifics.
But I think bubble size might be more of a factor of the type of beer (meaning heading proteins and such) and the level of carbonation moreso than what it was primed with. For example making one of my cream ales of a lager, they seem to have a head made of fairly small bubbles, and they are somewhat highly carbed...they are "Fizzy" and they also tend to leave nice lace on the glass.
The same with some of my Belgians, like my Blonde or a Tripel that is carbed higher that the traditionaly 2-2.5 volumes. They also tend to have tight bubbles in the head. It may be because of adjuncts like corn or sucrose in the boil, or the presence of Pilsner or Corn in the above recipes, or it maybe because these beers are intentionally more highly carbed than traditional ales, so their bubbles are tighter.
At least that is my theory...Like I said I've only, to my recollection primed with DME once, maybe twice and I can't even recall what beers it was done in. But they weren't my Belgians, Cream Ale or Lagers which had tight bubbles and nice lacing.
