OG Pre Boil-Post Boil

[Hawkeye Brewing]

still fairly new to all grain brewing and this may be a stupid question but going to ask anyway. I am brewing a ESB today but going to cut the recipe in half. Should my Pre Boil OG and Post Boil OG be the same targets as the recipe calls for or will they change?

 

[J A]

Enter the recipe in the Recipe Calculator and use the "scale" tool and it'll tell you everything. Yes, all the stats should remain the same. All grain half batches can be a little tricky depending on methods. Ingredients will consistently be proportional but water requirements may change. For instance whether you're boiling 6 gallons to start or 3, you still boil off the same amount so you need to start with proportionally more in the boil kettle. Efficiency can change when doing smaller batches because the depth of the grain bed during sparging can affect how well the sugars are rinsed from the grain.
Try to account for as many variables as possible and be a little flexible in terms of final product until you've brewed it a few times and know what to expect.
Good luck.

 

[Nosybear]

still fairly new to all grain brewing and this may be a stupid question but going to ask anyway. I am brewing a ESB today but going to cut the recipe in half. Should my Pre Boil OG and Post Boil OG be the same targets as the recipe calls for or will they change?

If you want the same beer, yes. If you use half the ingredients, excepting water, you'll get the same wort. The reason water is different is the boil-off rate which is constant. As JA suggests, use the recipe builder and scale function there.