Blueberry Lager….wait hear me out.

I don't have any useful experience to give you a first-hand response, but your question comes up regularly so that maybe some old threads will be helpful. Here's a link to a search that I did that looks for 'fruit' in the thread titles.

https://www.beeradvocate.com/community/search/121035784/?q=Fruit&o=date&c[title_only]=1&c[node]=8

 

Blueberry is very hard to pull off using just blueberries. I’d be willing to bet that blueberry lager he likes is made with extract flavoring.

if you want to go the actual fruit route I’d recommend freeze dried. Nuts.com

 

I'll back up @wasatchback on this. I've been brewing fruit beers professionally for 25 years now and the secret in my opinion is to use real fruit but then add a touch of extract to give it that aroma that everyone expects. If you don't use extract people seem to find it lacking although it's actually completely realistic.

I use Oregon Fruit puree because I have never been able to find a reasonable source for straight juice (although I did see something recently that I'm going to look into). I use 336#s of puree in 465 gallons of beer. It's added to the fermenter towards the end of primary at around 4 - 5 Plato/1.016-1.020 so that the ferment keeps going and the yeast doesn't have to rouse itself back up. I then add 8 oz. of extract just prior to racking.

 

I am not a pro brewer, but I do brew with fruit mostly blueberries.

what I do is use fresh blueberries, crush and boil them to prevent infection, then add in secondary. Usually 1 gallon of fruit per 5 gallons. Dam tasty. Raspberries seem to give off more flavor.

I did the same as above and bottled it last night. Tastes like yer drinking raspberries a lot.
Good luck