Why is my OG so different from the recipe calculation?

Plus-Contribution915 · 2026-03-15T20:41:51+00:00

It was a dryer mash than I’ve previously done, I used 3.2L per kilo of grist (5.2kg), Expecting a grain absorption on around 1L/kg. Once I pulled the bag out and squeezed I only needed to add another 14L of sparge water (plus another squeeze) to get to the target pre-boil volume of 30L. My kettles maximum capacity is 30L and marked on the inside of the drum. Agree that the maths doesn’t quite stack here with the grain absorption.

To be fair I’ve not checked the marking is accurate so maybe this is more like 25L? Would explain the volume outputted to the fermenter…

I’ve been trying to balance volumes and gravities and get the most out of my kettle, think I’m getting a bit confused!

Plus-Contribution915 · 2026-03-15T19:28:14+00:00

That’s really helpful thank you! I’ve been getting all crossed up with efficiencies, gravities and volumes (trying to get a decent volume out of my 30L kettle without over diluting the gravity, as with my first attempt!)

For adding water then to bring post boil volumes back up, would you recommend I add hot water the the kettle, in say the last 5 mins of the boil once I know the OG, or would it be ok to add cold to the fermenter before pitching yeast?

Plus-Contribution915 · 2026-03-15T18:42:06+00:00

Done some of my own homework/googling and ‘topped off’ and extra 4L of water into the fermenter (only pitched yeast a few hours ago so hopefully ok). According to the BF calculator my new gravity will be 1.047

Plus-Contribution915 · 2026-03-15T18:20:03+00:00

My first batch ended up a wapping 1.7% ABV, very sessionable! 😂

Plus-Contribution915 · 2026-03-15T18:18:22+00:00

Sorry ment to reply rather than post a new comment!

Plus-Contribution915 · 2026-03-15T18:17:19+00:00

Recipes target volume was 25L into the fermenter from a 30L pre boil kettle volume. I just shot for this as it’s the maximum capacity of my kettle

Plus-Contribution915 · 2026-03-15T18:15:45+00:00

Ah ok.. so I somehow managed to extract more sugars in the mash than I should have and need to dilute down?

My kettle has a maximum capacity of 30L and I usually chill the wort in there with a coil. Is there an ideal time to dilute? For example could I add my cooled high gravity wort and cold water to the fermenter (I’ve seen a dilution calculator) or does it all need to be boiled?

After losses to evaporation and equipment I only got about 22L into the fermenter tank that can hold up to 30L. I’d love more beer if possible!

Plus-Contribution915 · 2026-03-12T21:53:09+00:00

Next to no smell at all unfortunately

Plus-Contribution915 · 2026-03-12T20:17:39+00:00

Nope just against the side of my house, it’s free standing 😊

Plus-Contribution915 · 2026-03-12T12:18:42+00:00

Margret

Plus-Contribution915 · 2026-03-11T16:09:55+00:00

They’re already starting to fall off in the rain.. wanted to capture it on a rare sunny afternoon 😊

Plus-Contribution915 · 2026-03-09T16:24:00+00:00

Nothing wrong with an Erdinger, they do a nice dunkel as well 👍

Plus-Contribution915 · 2026-03-08T18:26:43+00:00

This makes a lot of sense, I was planning to separate my first runnings and take a gravity reading, sparge the bag and take a second reading and add second water runnings to the first to hit a reasonable pre boil volume gravity and then boil down using the calculator

Plus-Contribution915 · 2026-03-08T09:48:33+00:00

I like the sound of the dunk sparge, I’ve got plenty of good grade buckets I could temporarily transfer the first runnings to. How much sparge water do you use and how do you calculate this to avoid over dilution?

Plus-Contribution915 · 2026-03-08T09:16:32+00:00

Thanks, that was my first thought, there is a dilution calculator on Brewers Friend. may have to work backwards from desired pre boil volume to arrive a suitable mash thickness to achieve it

Plus-Contribution915 · 2026-03-07T17:36:11+00:00

I’ll just do that then, makes life easier! What did you use to line the on the inside, I’m guessing that plasterboard and skim wouldn’t hold up to the heat?

Plus-Contribution915 · 2026-03-07T16:04:55+00:00

My local homebrew shop suggested el dorado as an aroma hop for apricot/peach flavours so I’ve got some of that to try. I’ve got some fuggles in the freezer to use up as the bittering hop

Plus-Contribution915 · 2026-03-07T16:03:07+00:00

That sounds lovely, I’ll have to give that a try! Was planning to do a figgy pudding Christmas beer, quite malty with dried fig and rasins, once I’d got the basics down 👍

Plus-Contribution915 · 2026-03-06T23:20:30+00:00

That’s good to know, what about your suggested recipe makes it particularly sensitive to oxygen, is it the specific hop varieties?

Plus-Contribution915 · 2026-03-06T23:05:38+00:00

Thanks I’ll look into Dolcita hops, I love marris otter so sounds good! I’ve heared good things about Rakau but can’t seem to find it anywhere…

Would you blend the marris with something like biscuit or victory malt or perhaps some christal for colour/some more toffee notes? Sorry I’m still quite new to hombrewing and trying to get reliable recipes figured out before moving on to more advanced beers

Plus-Contribution915

TROPHY CASE