Missing gravity targets on Grainfather

[supergreenmini]

The last 2 brews i have missed my target gravities by some way. The first was on an 8KG grain bill so it was near the top and i think i pushed the top plate down too hard not allowing the recirculated wort to filter through the mash. So this one i can excuse.

The second brew was a twisted stout from Malt Miller. The target is 1049 and i reached 1043. Is this something to be worried about? Should i try and change my processes? i mash in carefully, stirring a lot and making sure there are no balls in the mash. This time i only rested the top plat on the mash but still there was always wort going into the overflow pipe throughout the 90 min mash. I think this is not abnormal (i.e normal) especially if the flow is not restricted and i have certainly had this scenario in other brews that have hit the target. I even stopped circulating after 20 mins and gave it all a stir to make sure circulation was going through the mash.

So could this be just 2 "off" brews, or do i need to start looking at each stage of my processes and identifying where improvements can be made? I have got into the habit of not thinking too much about it because the grainfather does all the work for me, but maybe i have become lazy?

[Hairybiker]

It's hard to say with just 2 samples. Since you have used it before it is not "newness" causing it.

I have had slow sparge and fast sparging brews and the slower ones are usually the better efficiency .
Did you hit the aimed for volume or was it higher?

[FUBAR]

I find with mine that a lot of wort goes via the overflow for the first 15 to 20 minutes, after that it settles right down with only the merest dribble going down the overflow and the wort is crystal clear by then as well.Which grain are you using ? perhaps the crush doesn't suit the GF, I use the malt millers Crisp malt and that is OK.

[f00b4r]

How old was the grain relative to previous batches?

[Fil]

I find with mine that a lot of wort goes via the overflow for the first 15 to 20 minutes, after that it settles right down with only the merest dribble going down the overflow and the wort is crystal clear by then as well.Which grain are you using ? perhaps the crush doesn't suit the GF, I use the malt millers Crisp malt and that is OK.

echos my experience also.. down to the same grain.. after the first 15-20 mins the liquor above the top plate sat a good 2-3mm below the overflow and was crystal clear alowing a clear view of the plate and its perforations.

after mixing in the grain Using a bung in the central hole as i kept knocking off the supplied bottle cap, i just sat the plate on the grain without pushing down..

[Dave S]

I've done 2 brews with mine so far and each has been a couple of points higher than predicted and beautifully clear wort. Not doing anything innovative just following the basic formula - recirc'ing for the entire mash, not pushing hard on the top plate etc.

[supergreenmini]

The last kit i did was the twisted stout pack from MaltMiller. Before that the brew was the last of a 25KG bag that was no older than 3 months from purchase. I was wondering whether the last bits of a large bag is made up more of the finer crashed grain (falling to the bottom) and whether this could affect my efficiency?

The wort is also crystal clear for me (so it is draining through the grain and filtering through but i would say it runs through the overflow pipe all the time. It has only been the last few brews that has missed my target. Before that i was on the nose or higher.

I plan another brew over the next few days so i will pay special attention to my mashing in and resting the plate on the top not pushing.

[supergreenmini]

I think i may have worked this out.

I use Beersmith to work out my mash volumes and sparge volumes as well as the OG i am aiming for. Last night a brewed a simple pale ale which has 4.5kg Pale Malt. Beersmith has worked out a Mash volume of 15.6l. during the Mash my kids decided to help me and i lost track of weighing my grain. I ended up putting 3.5KG into the mash and quickly figured this out when i started to circulate and the wart and it strained straight through the mash . So, after a quickly added 1kg of grain the circulation was started again and it built up until it overflowed down the pipe. (yay). I controlled thr flow during the complete mash so that it was only trickling over the overflow and towards the end it was fully open and not triickling over.

I was therefore confident of a complete mash.

I then sparged with 17.9l of water to give me a preboil volume of 29ltr. This is where the penny dropped `"lightbulb"`.

I work beersmith to a batch volume of 23ltr but i brew 25ltr batches to allow for the 2 ltr left in the grainfather. so i am brewing a grain bill for 23ltr but creating 25ltr batches, hence it drops below the traget OG.

The short of it is i am going to change my beersmith profile to not account for any loss in the grain father and accept less wort in the feremntor. But reached OG targets.

Does anyone have any different suggestions?

[FUBAR]

I use beer engine to formulate recipes with efficiency set to 75%,the mash and sparge volumes are worked out using the formula in the GF instructions. My brew length is 25 liters so I work out the sparge volume to give 30 liters preboil and I get 25 litres in the FV every time.

[Hairybiker]

Did you hit the aimed for volume or was it higher?

I did mention this earlier. If you are using a 23L recipe and getting 25L then expect 23/25 of the OG. Unless you are getting better extraction rates than calculated for.

I did a brew to day and it was lower than expected, I am blaming the malt as it has been very fast to sparge - basically pouring through, and I only got 1050 @ 20L instead of 23L.
But since it is going in a cornie its ok.

[supergreenmini]

At the time i answered yes i did hit my volumes as i was taking 23ltr to be the volume in the fermentor and not in the boiling pot after boil. That was my oversight and lesson.

I now have two profiles in beersmith. One for my intended brews of 25 ltr and one for 23ltr as i like to try some of the kits that the stores provide.

Thanks all