Why is my OG off..

[sexysouthwest]

I made a choclate coffee stout from Barley bottom and the OG was meant to be 1050 and i got 1044 why is that ow can i get it too 1050 next time what am i doing wrong and what affects the OG.

[kay-jay]

I made a choclate coffee stout from Barley bottom and the OG was meant to be 1050 and i got 1044 why is that ow can i get it too 1050 next time what am i doing wrong and what affects the OG.

Hi,
there are a couple of things which could have thrown your og off. firstly incorrectly weighed grain bill. but in this case i would rule that out as i'm sure BB would check this before sale. next up is too much brewing liquor. was the recipe for 23litres and did you collect more than you should. did you check the amount of liquor with a water calculator. another possible culprit is the efficiency of the sparge. did you batch or fly sparge? the recipe may be compiled for an 80 percent efficiency and you may be less efficient with your method which would throw off your results. finally it could be the result of incorrect mash temp but the more experienced brewers could tell you more than i about this. basically tho depending on the temp more or less fermentable sugars are released from the grains in the mash. it could also be a mixture of any or all the above.

KJ

[dhalse001]

Hi,

I've been having similar problems too. I also get my grain from BB, but their service is super good and I doubt it's the grain, although I might have a go with another just to check, and if same problem occurs then straight back to BB.

I'm coming to the conclusion that it's my sparging. I do 30 mins at best (fly? - is that the name of the spinny sprinkler I use?). I've started doing the iodine test to check for complete conversion. I used to wait for 1 hour on the mash, and then sparge regardless. But now I'm waiting 1 hour, stirring, wait another 30 mins then iodine-starch test. I found today that I still hadn't reached full conversion, but I'm impatient and started sparging anyway.

One thing you can do, is just when you reach your pre boil volume, then fill up your vial and test the OG from the mash. I did today and found 1.020. Hence I'm not really getting all the sugars from my mash into the kettle, ie all the efficiency I should be getting and I blame my sparging process. I read somewhere that you shouldn't sparge below say 1.008 (which is why I was really testing) due to tannins and other god knows what.

Regards,
Dave.

[steve_flack]

But now I'm waiting 1 hour, stirring, wait another 30 mins then iodine-starch test. I found today that I still hadn't reached full conversion, but I'm impatient and started sparging anyway.

You really should get complete conversion well before then - around 30 minutes in my experience. For your test you need to ensure you have no grains in the liquid you test and you're only testing liquid.

[Horden Hillbilly]

I'm coming to the conclusion that it's my sparging. I do 30 mins at best.

Try slowing this down a little, I normally fly sparge a brew for around the 40-45 minute region & normally hit around 78%-80% effiency.

[Deebee]

Hi,

I've been having similar problems too. I also get my grain from BB, but their service is super good and I doubt it's the grain, although I might have a go with another just to check, and if same problem occurs then straight back to BB.

I'm coming to the conclusion that it's my sparging. I do 30 mins at best (fly? - is that the name of the spinny sprinkler I use?). I've started doing the iodine test to check for complete conversion. I used to wait for 1 hour on the mash, and then sparge regardless. But now I'm waiting 1 hour, stirring, wait another 30 mins then iodine-starch test. I found today that I still hadn't reached full conversion, but I'm impatient and started sparging anyway.

One thing you can do, is just when you reach your pre boil volume, then fill up your vial and test the OG from the mash. I did today and found 1.020. Hence I'm not really getting all the sugars from my mash into the kettle, ie all the efficiency I should be getting and I blame my sparging process. I read somewhere that you shouldn't sparge below say 1.008 (which is why I was really testing) due to tannins and other god knows what.

Regards,
Dave.

I'd say this is way too fast. if i am sparging a 20 litre batch ( so say i have to add 19 litres for deadspace etc9 then i am looking at 75 minutes or more all depending... this sounds too fast

[dhalse001]

Thanks guys,

I'll be definitely slowing the whole thing down next time and seeing how I get on. I've been typing in 75% in ProMash software, but nowhere near 75%.

Regards,
Dave.

[dhalse001]

But now I'm waiting 1 hour, stirring, wait another 30 mins then iodine-starch test. I found today that I still hadn't reached full conversion, but I'm impatient and started sparging anyway.

You really should get complete conversion well before then - around 30 minutes in my experience. For your test you need to ensure you have no grains in the liquid you test and you're only testing liquid.

Hmm. I've just been grabbing a tablespoon out of the mash, a few bits of grains there but didn't think it was anything of concern. I would have thought (wrongly by the sounds of your post) that the grain as well should all be converted after 1.5 hours?

Dave.

[steve_flack]

I don't know why but the grains often turn purple in a starch test even if the mash is fully converted.