How can I up the abv of my wheat beer?

[Alex.mc]

I did a kit AG wheat beer, but didn't seem to get as much boiloff as expected and had an OG of 1035. I'd intended this to be a Blackberry wheat beer, and froze, and then pasteurised about 3kg of blackberries and chucked them in after a week. It's been a couple of weeks now with some movement on the airlock until a few days ago. I just checked the FG and it's 1012 which I make to be about 3.2%.
I tasted and it was nice enough, but I feel it could do with a bit more abv really. It has a lovely colour, and tastes fruity, but a bit thin and fruit-drink like.

Any suggestions?

 

[dad_of_jon]

500g of dwe would be a good start

 

[Alex.mc]

DWE? Or DME?

 

[baggybill]

I think you might be too late now mate as the time to catch it would have been at the start with additional DME, dextrose or even can(s) of golden syrup (or all three!).

I have read in the past of adding additional fermentables half way through (maybe Brewdog?) but I have zero experience of this.
Just drink twice as fast and move on to the next one

 

[Zephyr259]

Sugar in the fruit with have nudged you up a bit but probably not much. At this stage you're probably best just enjoying a low abv brew.

 

[Alex.mc]

Thanks chaps, I've cogitated all weekend, read up on adding fermetables etc.... gone round in a few circles, found a packet of light DME, pondered trying to split the brew and try adding to half etc.....
Then decided I'm still a noob, and having watched the Adrian Chiles doc last night, decided to bottle it and enjoy it at 3.2%!
My reading brought up the stuff about carbonation enhancing mouthfeel, so it will be interesting to compare it to the flat sample I tried.

 

[Dutto]

Always remember that anyone can make a drinkable "Falling Down Juice" (just keep adding more sugar or ME) but it takes real skill to make a palatable session brew with an ABV of below 3.5%!

 

[Alex.mc]

Lol! I take your point, however any palatability will be down more to luck than skill on my part! :-)

 

[rank_frank]

I fermented 2Kg of Blackberries in 1 gallon of water years back when I made country wines. Normally you'd add about 1Kg sugar to this but I decided to see what contribution the fruit alone made. I got a quite nice drink of about 6% ABV. I'm assuming that you've made 5 gallons so your 3Kg of Blackberries might've added 1.8% extra ABV to your beer

 

[Alex.mc]

Well it's still fermenting! I hear a burp I'm the airlock about once per 20-30 mins currently, with the fermentation room being a steady 19.5-20.5c.
Am I right to assume that the sugars in the fruit are taking a while to get done? I'm happy to leave it for a while.

 

[Alex.mc]

And I'm still hearing the odd burp from the airlock two weeks after my last comment above!
Any idea how long it will continue? Does fruit sugar take a lot longer to ferment out?

 

[AdeDunn]

You can't judge fermentation using airlock activity, even temperature and air pressure can cause the airlock to burp. The only way to be sure is to check the specific gravity about 3 to 5 days apart and compare them, if there is no change, then it's most likely finished. If there's a change, it's not finished.

 

[Alex.mc]

Ok, will check it.
The airlock seems to have always moved the same way, expelling pressure, but on reflection the room it is in is always warming slightly at the times I am in it. Temp differential won't be huge, maybe 2-3 degrees or so, but if it is moving the other way on cooling then I won't have been in the room at that time.