I'm wanting to do the same & brew a 5.5 gal batch for one of my taps... What % abv do you get & would you mind sharing your recipe?
So, over the past few(or more) years, I've probably brewed this ~7-8 times in 10G(~40l) batches. The base varies between 7-10%abv based on mood, yeast, etc..
The base recipe is as follows
x lbs sugar. I tend to use organic cane or beet sugar, usually not bleached. More on the specific amount following recipe.
4 limes(through the vitamix to a pulp)
4 lemons(with the limes)
3-4 lbs ginger, thinly sliced(sometimes frozen depending on when I get it and when I brew).
For sugar it is 1lb/gallon = 1.040 sg. so I adjust depending on how strong I want it..
I tend to start my boil, add ginger. When I get to a boil, I pull some off to add to some sugar, then add the solution back to the boil, repeat until all sugar is added. Boil time is roughly an hour when all sugars are added. Then I add the lemons and limes with 10-15 mins left to the boil.
I will also add yeast nutrients at 15 mins.
I tend to then whirlpool and transfer hot to the fermentor(I have a 1/2bbl keg dedicated to ginger beer fermenting). So no chill. Let it cool to pitching temp, add yeast, wait until done, transfer to kegs, carb(high), chill and serve.
I've played with yeast, I think so far belle saison is the favorite, followed by S04(with molasses). I will do late additions of molasses or others, pineapple juice seems to not ferment out and leaves some sweetness.
The base with lavlin(sp?) champagne yeast ends with a dry "Reed's" ginger ale like beverage. Where with some molasses and using S04 you get something sweeter, with a different character.
Of the things I found,
Boiling the citrus fruit for a while with the solution adds something.
Leaving the ginger in the boil kettle and not transferring it to the fermentor lessens the ginger flavor some, but is much easier to deal with.
Sugar adds volume even when dissolved, and in a 10G batch shooting for 10% abv, you are adding in excess of 22 lbs of sugar. This is a not insignificant volume of addition.
Yeast nutrient and patience are important when doing higher abv.
Due(I think) to the lack of proteins, this requires a higher carb level. I keep mine on tap at ~30PSI@~38F. this leaves it with decent carbonation. The head dissipates quickly(like soda).
https://www.webstaurantstore.com/golden-barrel-organic-cane-sugar-50-lb/104SUGORG50.html is a great place for bulk sugar. Also great for stainless sinks/tables, glassware, silverware etc.. They offer free shipping the ends up as ~2-3day fedex ground.
I have not bottled. Though after ferment, sometimes I end with more then 2 kegs. I throw the rest into 1G apple juice jugs, and they tend to disappear from the beer fridge quickly even though they are "flat". I do have 2 adult children(and partners/friends), so things turn over pretty quick.