Low OG question

[SnailAle]

Gday all,

I just finished doing a wheat beer today and the OG is under the estimated. It's meant to be 1050 but it's closer to 1038.

I don't know exactly what I did, I think I had to much mash water to start and when I sparged I was hesitant to put too much in, maybe that?

Anyway, I kind of understand how to fix this in future, my question for this batch though is will it still be a nice beer at the end even if it's got a low OG? Or does that drastically affect the flavour to a point where it's pretty average?

 

[Dan Pratt]

did you measure the gravity post mash before sparge? Did you measure gravity after sparging? Was you preboil volume what the software estimated?

 

[SnailAle]

Nah I bought a grain and grape AG kit. Which comes with recipe, didn't have a preboil volume so I was just guessing. The batch size ended up preyty close though.

As for measuring the sg I didn't do it until I'd finished the whole run. I just assumed following the recipe it should have been ok.

Will it still be a drinkable beer?

 

[manticle]

Possibly.

Recipe and mash process will help offer some realistic advice.

It's all about balance.

 

[SnailAle]

Possibly.

Recipe and mash process will help offer some realistic advice.

It's all about balance.

I'll put up the recipe when I get home, having a few store bought hefeweizen at the moment actually [emoji106]

 

[SnailAle]

@manticle

 

[Dan Pratt]

the recipe is the easy part of brewing.

knowing your system and understanding what you boil off, trub and losses are will help you to figure out starting volumes, sparge volumes and final volumes.

checking gravity is to be done several times before final volume, this is until you know your system.

 

[SnailAle]

the recipe is the easy part of brewing.

knowing your system and understanding what you boil off, trub and losses are will help you to figure out starting volumes, sparge volumes and final volumes.

checking gravity is to be done several times before final volume, this is until you know your system.

Yeah I get that, I'm new to brewing so I expected this kind of thing while I learn the ropes, my main question is more around whether this beer is likely to end up drinkable or not.

 

[fletcher]

what was your mash temp and what yeast are you using?

 

[manticle]

View attachment 108397

@manticle

I'm struggling to read that on my phone but a low OG hefeweizen shouldn't be a huge drama. It may be thinner/more watery, it may be slightly more bitter but I wouldn't stress.

What I would be trying to find out, though is from where in your process the deficit is coming.

 

[SnailAle]

what was your mash temp and what yeast are you using?

66 deg and using danstar Munich classic.

 

[SnailAle]

I'm struggling to read that on my phone but a low OG hefeweizen shouldn't be a huge drama. It may be thinner/more watery, it may be slightly more bitter but I wouldn't stress.

What I would be trying to find out, though is from where in your process the deficit is coming.

I am still confused when I'm given a boil size and end volume but not an initial volume to start the mashing.

So I think that's where I went wrong. I started with 26litres and by the time it came to sparging it hadn't reduced a lot, so I went light on the volume of sparge water used. I'm assuming that was where I went wrong.

I thought about sparging with more and then boiling for 90 minutes rather than the recipes 60 minutes but wasn't sure if that'd be worse for the beer than leaving it.

 

[manticle]

Every system is different, every kettle has a slightly different evaporation rate

Early part of brewing is dialling in your system and tweaking recipe and process to suit the actual numbers.

Fill your kettle with a known quantity of water and boil for an hour to calculate your evaporation. This will be a consistent amount over time (ie - if you lose 5 litres in an hour, you will lose 10 in 2 hours, regardless of actual boil volume).

Allow about 1 - 1.1L loss per kg of grain from absorption. You will also leave a small quantity behind when you empty the tun. Calculate what this is.

Allow a couple of litres loss post boil due to hop and protein trub.

Now you have a boiloff rate and trub losses so you know how much liquid to get into the kettle to get close to desired final volume. Mash in with at least 2.5 L -3 water per kg grain. Mash, runoff and add enough sparge water to make up the difference. In the case of full volume, single vessel (one method within BIAB for example) just mash in at the beginning with the full liquor volume.

You need to be able to measure everything accurately.

 

[Sidney Harbour-Bridge]

You could add some DME to bring the gravity up if you like

 

[Edd Mather 6]

Every system is different, every kettle has a slightly different evaporation rate

Early part of brewing is dialling in your system and tweaking recipe and process to suit the actual numbers.

Fill your kettle with a known quantity of water and boil for an hour to calculate your evaporation. This will be a consistent amount over time (ie - if you lose 5 litres in an hour, you will lose 10 in 2 hours, regardless of actual boil volume).

Allow about 1 - 1.1L loss per kg of grain from absorption. You will also leave a small quantity behind when you empty the tun. Calculate what this is.

Allow a couple of litres loss post boil due to hop and protein trub.

Now you have a boiloff rate and trub losses so you know how much liquid to get into the kettle to get close to desired final volume. Mash in with at least 2.5 L -3 water per kg grain. Mash, runoff and add enough sparge water to make up the difference. In the case of full volume, single vessel (one method within BIAB for example) just mash in at the beginning with the full liquor volume.

You need to be able to measure everything accurately.

Yup , accurate measurement is key in brewing , one thing though, a high gravity wort @ 1.055 ° {copper charge} will, have a lower evaporation rate than say one at 1.038, I'd say take note of how the boil evaporates on brew day with each brew , and measure the gravity by hydrometer (@20°c) @ let in to the copper.