Too low OG

[Florin]

Hi,

I just got my Brewzilla 65L and i tried to make my weissbier recipe with a target of 23L. I added more grains, to be sure i don't get a low abv beer, even if i don't get a very good efficiency.

3 kg (54%) — Weyermann Wheat Malt, Pale — Grain — 3.9 EBC
2 kg (36%) — Weyermann Vienna Malt — Grain — 5.9 EBC
280 g (5%) — Weyermann Acidulated — Grain — 3.5 EBC
280 g (5%) — Weyermann Melanoidin — Grain — 59 EBC

I used Brewfather to do the calculations and as i had the big brewzilla a thought i will do no sparge and start with full water volume, which was calculated to 37.25L by Brewfather.
I even added the juice from a lemon trying to lower a bit the Ph of the water (which is around 7.5 in my area).
Based on Brewfather and according to my grain bill, i should have an OG of 1057 and i was thinking, even if it's going to be lower, there is no problem.

The sad part: after mashing at 67C for 1h and 15min, then boiling 1h:30min, i got an OG of only 1038. Ended up with 25L in the Brewzilla and almost 24L in the fermentation bucket.
I was so shocked, as I've managed to get a higher OG (1040) with the BIAB method in a 20L kettle with only 1h of mashing and way less grains (per fermentation quantity).
My big question is, what went so wrong, so that next time i should fix ?
- can it be the root cause the fact that I've put the grains in the water at 70-71C instead of 67C ? ( i was thinking the water temperature will drop fast when i add the grains, but unfortunately, it stayed at 70C and dropped very slowly to 67C, most probably because of the large water quantity)
- or because of the large volume of water to start with combined with high Ph value ?
- can it be the no sparge ? but I did used a lot more grains ... I thought this will bee enough to get at least 1045.
- what else can it be ?

The saddest part is that i didn't even had a bag of Dry Malt Extract to fix this.

 

[Sandimas]

Your first brew with it?

You'll need to work out what sort of efficiency you get as this can depend on lots of things, you won't know this until you've done a few brews. Expecting to hit your target OG spot-on first brew is shooting in the dark a bit.

Sparging would certainly have helped, sounds like you used too much water too as you ended up 1L over target volume.

 

[Rodcx500z]

Hi Florin, i did my first brew in a brewzilla 35L yesterday, i did a bitter scaled to 21L my concerns was the amount of water brewfather was asking for but i went with it, i used the sparge method i used the recirculation all through the 75 min mash and did a 76c mash out for 15 mins i got 21L in the fv and was one point over og, did you recirculate while mashing also did you use the top plate i was a little worried i couldn't stir the mash, other than this i can't help

 

[Florin]

yes, it was my first brew with it, but the difference is huge from 1057 to 1038. As i said, i was not dreaming to get the perfect efficiency, but for me it seems way off.
I did use the recirculation all the time, but i didn't use the top plate, as i did stir grain from time to time. I saw that many don't use the top plate with no issue.
For sure next time I will use the sparge method, to see how it's going.

 

[Hanglow]

For no sparge, about the highest preboil sg you could hope for with that grainbill and that amount of water would be about 1.043 I think. It's quite a lot of water for a 23l/24l batch.

Your other losses might come from; too short a mash at too high a temperature (eg do a step mash to cover more bases), incorrect grain crushing (wheat needs a finer crush) and also you don't know what your mash pH is based on the info you have given, your water pH is irrelevant, it's the alkalinity of the water you need to know and adding the juice of a lemon to a mash that already has a sizeable portion of acidulated malt could have driven it too low

 

[The Baron]

Hydrometer check required (basics first)
And as it is so low are you sure you weighed the grains out correctly as I have done this before and is a basic but simple thing to get wrong especially if you are using the tare on a set of scales
Just a thought apart from that it is way low

 

[Florin]

Hanglow: good point about ph/alkalinity. I did thought Ph is the main , didn't thought of the alkalinity.
I didn't measure the preboil SG, i had 1.038 after boil, at 25C.
the baron: The hydrometer I have used before, hard to believe it's not ok, but can be (i hope it's broken :)))) , but i did taste the wort ... seems very diluted indeed, but will try to check the hydrometer.
The grain weights: i had them from the shop, grinded and sealed separately (3kg, 2kg), from the same shop i used before (same grind size). But indeed i didn't weighted them, still they seemed fine. But for sure i cannot be sure now

 

[Rodcx500z]

Hi Florin, when i worked in the bakery we had a saying, suppliers make mistakes to, just a thought

 

[foxbat]

Did you get a chance to inspect the crushed wheat before you used it? It's huskless, tough and needs to be crushed on a finer setting than the barley.

 

[Florin]

I don't remember exactly which one had husks, but one had. Anyway, i had a lot of fine sediments in the resulting wort. Even in the hydrometer recipient there was 3 cm of sediments after some hours. (i forgot it there)

 

[The Baron]

Do you think the sediment in the trial jar may have distorted the reading?

 

[Florin]

i'm not sure, the reading I've done was before letting it stay (had no sediments build up on the bottom when i checked the OG value)

 

[The Baron]

you will be able to judge the brew once you are drinking as the alcohol content is quite a large gap so experience will tell if it is nearer the expected OG and that it is other forces acting that may have caused a wrong reading.
3 pints of 5% I am talking crap
3 pints of 4% still talking crap but coherent crap

 

[Donegal john]

What temp was the sample at when you tested it with hydrometer ?

 

[Florin]

25C

 

[Donegal john]

Did you adjust for correct abv as most hydrometer read correctly at around 20c

edit
Just checked and it hasn’t made a great deal of difference.

 

[Sandimas]

I just plugged the figures and looks like you got 53% efficiency which is very low. Most recipes are sized for 75% efficiency, we all get different figures due to equipment, method and grain crush, but nowhere near as low as that. I get 68% with BIAB. I don't have a Brewzilla but I would expect it to be 70% or above.

Wheat beers can be a problem to mash, many people add in rice hulls to bulk it out and get the liquid into the grains, but your figures still seem far too low. This might seem like a stupid question, but was the grain actually crushed? That's the only thing I can think of to produce a poor efficiency, or something wrong with the mash temperature: is it reading correctly?

Failing that, suggest doing another brew with a really simple grain bill, maybe as SMASH with just base malt and see what that comes out at.

 

[Florin]

Many thanks guys for all your input. This is how I feel also … way too low the efficiency, as i said, i did better on my first ever all grain brew with a biab method and way less grains. This time I exaggerated the grain bill (brewfather saying final abv of 6.3%)
The grain was crushed for sure.
Regarding the temperature, I've added them when brewzilla showed 71C, hoping to drop fast to 67C. Seeing not dropping, i checked with another meat thermometer at 10-15cm bellow surface ( pretty much into the grains ) ... 70C. I let the temperature to drop to 67C (based on brewzilla and didn't double checked again. The pump worked continuously and I did stir the grains from time to time.
Now, that you asked ….. I'm thinking maybe I should have double checked the temperature from time to time. For sure I will do that next time. (noted)

 

[fgoulding]

I brewed a similar recipe to yours in my Brewzilla 35L. In fact, my grain bill was almost identical but my Brewfather water calculation was for a total of 31.4 litres. So maybe that's your key issue. Plus I would have expected a higher grain bill for no sparging.

Anyway, I've been steadily increasing my mash efficiency after each brew and these are a few things that have helped me:

• Mashing in at 3C above the target mash temp
• A mash rest for 10mins before recirculation (normally at 65C for most of my recipes) and then mash with recirculation for 50mins
• Mash out for 10mins at a 75C with no recirculation
• A few hand fulls of rice hulls in the grain bill which does wonders for recirculation
• I ditched the top place and the adjustable rod in the malt pipe (I have a bottom plate with no hole but you could also just plug the hole)
• I use a siphon aerator on the end of the recirculation arm to distribute wort

I must admit that it took me a while to realise that I needed to keep changing my Brewfather equipment profile to account for changes in mash efficiency. I started out at 65% and currently, I'm getting 81%.

However, I've only done no sparge once and, even with a 10% increase in grain, the efficiency sucked. So I've never done it again!

By the way, this is my siphon aerator which I found on eBay:

 

[Florin]

Thanks!
And for sure i'll sparge from now on.