Opinions on boosting OG in Weissbier

[Hpal]

Hi All,
I brewed my Weissbier again the other day, it has turned out very good in the past, but this time for whatever reason my OG was a bit low, most likely an efficiency or boil-off rate issue and i'm slack sometimes with taking measurements. Anyway I was supposed to end up with 1.050sg after adding dextrose towards the end of the boil (targeting banana, there are articles suggesting 5% dex will promote banana flavour) but I measured the gravity at pitching time and it was 1.043. I would prefer it a bit higher as a hefe that's too thin doesn't appeal to me, and higher OG can promote banana flavours too.
So, I was thinking of adding a small amount of additional dextrose or dry malt say 300g to bump the OG up just 2 or 3 point to bring it closer to where I wanted without going overboard, thoughts??

 

[Jack of all biers]

Adding dex won't add much body. OG yes, but body meh.

I calculate your actual efficiency as ~73%, which brings your FG down 2-3 points also (circa 1.010). Adding an additional 300gm calculates to a new OG of 1.046 with the same FG of 1.010 leaving a new ABV of 4.61%. Of course this is calculation only, but dex is like sucrose and doesn't add much in way of FG, unless you start piling it on (think an additional Kg, which brings up OG to 1.052 and FG to 1.012, but it'll still likely be thinner in body than you wanted).

EDIT - adding some dry or liquid wheat extract would bring the body up however. If you think about it, you are adding back what you lost in efficiency in the mash. EG. 1.5kg liquid wheat extract (1.5kg Coopers wheat malt extract for example), will take your OG and FG back to where you were aiming (circa OG 1.053 FG 1.012).

 

[Hpal]

Cheers, I'll add a small amount of malt adjunct

 

[keine_ahnung]

Hi Hpal,

as a professional brewer in bavaria (where Weißbier was invented) my advice would be:
1. Your recipe and mash schedule looks quite good. Tettnanger is great in Weißbier IBUs are on the high side for a Weißbier...this will also have a bit of an affect on how malty/full-bodied the beer comes across. (Masks the sweetness to an extent)
That's also a pretty big aroma addition for a Weißbier. But hey, if you like it hoppy, knock yourself out

2. The theory that an increased proportion of glucose in the wort composition increases banana aroma (Isoamylacetat is the responsible compound for this aroma) is widely discussed and disputed. One of our professors at uni did his Phd on Weißbier and as we were discussing this topic, he expressed that he is unconvinced of this theory and that is also the general concencus among the experts and in the industry here.

Of MUCH greater influence are all other fermentation properties; yeast type, cell count, temperature, temperature vs time, removal of "spent yeast" towards the end of the fermentation, conditioning, lagering, movement within the beer during fermentation and thus ratio of height:width of the fermenter.

If you want to increase the "banana" in your Weißbier, in general: appropriate yeast, underpitch a bit, ferment a bit warmer.

To be honest, I'd completely forget about adding dextrose and that kind of stuff. I used to do a bit of that back in my homebrew days. But in hindsight, I wish somebody had have given me some good advice on mashing and making sure that I'm getting that right.
The mash is critically important! If it's shit...your beer will be too
But I'm also a bit of a purist..

3. You could happily add a bit of Munich malt to fill out the body a bit. (Assuming that still fits your colour expectations.) And/or you could swap the carapils for carahell. But again, will increase your colour a bit..

 

[MHB]

Interesting to read keine_ahnung's comments. I've been playing around with glucose additions to Weiss for a couple of years. I think there is a measurable increase in Banana if you add a little - but (as always) everything else has to be set up to favour the production of Banana and Bubblegum or it just wont happen. That's mainly down to yeast/ferment management.
Also a word of caution about the term "underpitch" I think pitching at the lower end of the recommended range for Ales would be a more accurate expression. That's quite a lot more yeast than most home brewers think - do the numbers.
The recommended Ale pitch rates being 0.5-1Million cells/mL/oP
For this beer at say 0.5*EXP6 X 40,000 X 12.5 = 250,000,000,000 or 2.5*EXP11. Wyeast claim 100 Billion cells or 1EXP11 so one pack for this brew its really under the low end (by more than half).

The problem really is one of efficiency. I notice you are milling your own grain. I strongly suspect you are doing a pretty crap job!
You have 8kg of malt, just roughly there is about 75% extract available so 6kg, that in 43.5L would give you over 13oP (not including your 0.3kg of dextrose) or 1.052, there is plenty of extract available - if you can get it out.
Next time ask Brewman to do the milling for you, for BIAB (set the milling option to fine or extra fine) and see if that gets you the OG you are looking for, that or have a long hard look at your own milling and make sure you are getting the type of grist you need.
Mark