Halving recipes advice

[DDHIPA]

Hello all,

I recently brewed the Verdant Lightbulb All Grain Recipe kit from The Malt Miller. It tastes amazing, FG hit bang on and I got a lot of things right but there is still a lot to improve on and streamline...
And rather than brewing 20L batch after 20L batch I have ordered the micro pipework kit for my Grainfather and I am planning on reducing my batch size to 10L.

I know I am to keep times and temps the same, and halving the Grain bill is easy enough but my main concerns are....

Do i also halve the yeast quantity or do I keep it the same?
Do I halve the hop quantities? (i have read conflicting things)
Do I need a smaller fermenting vessel or will my 23L plastic wide kneck carboy suffice? I know that too much headspace isnt a good thing so I am worried about increased oxidation....

Is there anything else I need to keep in mind when halving a recipe?

Thanks in advance

 

[Baz Chaz]

I moved from my standard 23 litre brewing to 15 litres, I use brewing software which makes it easy to simply change the recipe from 23 litres to whatever amount you want to brew. Literally click on the 23 litre box and change to 15, amounts adjusted automatically.

Found the advantages are less time to get liquids up to temperature and also cooling. Less weight to keep lifting around. Bottling quicker as well.

 

[Scrattajack]

Regarding the hops, I believe they should be reduced pro-rata. This is based on the Graham Wheeler British Ale book, where he lists the ingredients for three different batch sizes and that is the case there.

 

[AdeDunn]

I moved from my standard 23 litre brewing to 15 litres, I use brewing software which makes it easy to simply change the recipe from 23 litres to whatever amount you want to brew. Literally click on the 23 litre box and change to 15, amounts adjusted automatically.

Found the advantages are less time to get liquids up to temperature and also cooling. Less weight to keep lifting around. Bottling quicker as well.

Same, I use Beersmith 3 with 2 profiles, 1 for the full size recipe, 1 for the volume I actually want. Type the recipe in full size, then use the scale recipe tool to adjust it to the smaller volume (14 litres in my case) profile. 14/15 litres is roughly enough to fill about the right number of bottles to fill a bottle crate usually see, hence why I went for that (15 litres gives you the spare for wastage on things like filling the bottler etc, where 14 litres you run a bit close and often I end up 1 bottle short of filling the crate). If I am using a dried yeast like US 05 I just use the whole packet as end of the day it's cheap, and over-pitching (not sure it's even possible with dried yeast...) didn't seem to have any negative impact, but if using something like kveik I scale it down.