First partial mash...missed on the O.G. by a bit...why?

[dgarner58]

Did Dry Dock Urca Vanilla Porter pro series partial mash kit from northern brewer today. I followed the instructions almost too a "T" but my O.G. came up short. It was supposed to be 1.061 and i came out with 1.052. I know this will yield a lower ABV beer but i figure it will still taste good...but what i want to know really is what i did wrong. I took my gravity reading post boil. Only thing i didn't really nail was the mash temperature. Instructions said to mash @ 156 degree +/- 1 to 2 degrees. I held 153 pretty constant for the whole hour. It dropped to 151 for a couple of minutes then crept back up.

Did i not sparge well enough? Could just a couple of degrees make that much difference? I mean...i guess i am glad it didn't come out like WAAAY off but i still feel it is pretty significant.

I guess i will know in 6 weeks.

 

[BrewerBear]

May have not got top off water stirred in good.What temp did you take your reading at? The lower mash temp would not have caused O.G. to be off.

 

[GrogNerd]

I would agree... stratification.

with the majority of your fermentables coming from extract, unless you filled to OVER 5 gallons in step 16 your OG should be closer to what the recipe says it is.

the other possibility is if you didn't compensate for temperature when you took your OG. unless you used a refractometer, higher temperature wort will give you a lower gravity reading

 

[dgarner58]

temp of wort at reading was 75 degrees. i added .002 to compensate. hydro said 1.050. i did top to slightly more than 5 gallons by just over a quart. that doesn't seem like enough to drop it by .009 though. the lme did give me some problems when i was putting it in as i poured it straight from the bag and the steam caused some of it to stick to the bag...so i lost a tiny bit of it to that.

maybe just little things adding up?

 

[unionrdr]

The first thing to be concerned with in AG or PM is efficiency. This refers to how well conversion from starches to sugars. The higher the efficiency,the higher the OG. I found that out in PM very quickly. Also,even with BIAB,you have to use a paint strainer bag,which can be rolled over the lip of the BK/MT. This allows the mash to be stirred when grains are added to the heated water. I add the grains at 150F,then stirr quickly to break up dough balls,& ensure all grains are evenly wetted.this is the important step to high efficiency. The grains must be broken up well to get good efficiency. It should look like thin,grainy grits in the kettle. That is,if you cook your own grits.
Also make sure you sparge well to get up to your total boil volume. This will also work toward keeping the OG up. Not to mention,a bit more flavor wothout darkening the color. I prefer to get more out of the grains,rather than just adding more spring water to the kettle.
AS an example,I mash 5lb of grains in 2 gallons of water at 152-154F for 1 hour wrapped in my thinsulate lined winter hunting coat. The temp will usually come up 1 degree by the end of the hour mash. This should help with fermentable levels by stabilizing mash temp. I then sparge with 1.5 gallons of 165-168F water for total boil volume of 3.5 gallons in my 5G BK/MT. These things should help your efficiency,& thus raise OG's.

 

[GrogNerd]

temp of wort at reading was 75 degrees. i added .002 to compensate. hydro said 1.050. i did top to slightly more than 5 gallons by just over a quart. that doesn't seem like enough to drop it by .009 though. the lme did give me some problems when i was putting it in as i poured it straight from the bag and the steam caused some of it to stick to the bag...so i lost a tiny bit of it to that.

maybe just little things adding up?

a quart will move it by maybe .003, maybe that part clinging to the bag was another .001 or 2, so yeah, it does add up

I wouldn't worry; you made beer!

 

[Uziyahu]

You may not have done anything wrong. The kit assumes that you will get a certain percentage for efficiency, but you got something else. Efficiency is determined by the process you use, but it's not a right way/ wrong way kind of thing. More efficiency isn't necessarily good, and less isn't bad.

So I looked at the NB kit instructions, and for partial mash, they suggest pouring water over your bag to sparge. I have found that is a very poor way to sparge that leads to low, low efficiency (for me). The water tends to run down the side of the bag instead of through the grain. Instead, I take the whole bag and dunk it in a container of sparge water. That might help your PM efficiency in the future.

 

[dstranger99]

It sounds like you added to much water for top off, I always keep my hydro in the bucket to see where I'm at, pouring a little water at a time........But no big deal, you'll just have a lower ABV.

 

[unionrdr]

More efficiency is always a good thing. It'll ensure that your OG's are in the range the kit or recipe intends them to be. I think efficiency is the first thing a brewer needs to learn in regard to AG or PM brewing.

 

[Uziyahu]

More efficiency will cost less, because you're using less ingredients. But it's not like a brewer who gets 65% efficiency is a bad brewer while a brewer who gets 85% efficiency is a good brewer. It's only really important to know and understand so you can formulate your recipes properly and hit your target OG.

For the OP, you can expect to not hit your OG for the first several PM or AG batches, because you are learning your process and what efficiency you get at that process. I switched to BIAB AG brewing four or five beers ago and still haven't quite nailed down my process enough to reliably predict my OG like I would like to. It took me that long to find a process I like.

 

[libeerty]

More efficiency will cost less, because you're using less ingredients. But it's not like a brewer who gets 65% efficiency is a bad brewer while a brewer who gets 85% efficiency is a good brewer. It's only really important to know and understand so you can formulate your recipes properly and hit your target OG.

For the OP, you can expect to not hit your OG for the first several PM or AG batches, because you are learning your process and what efficiency you get at that process. I switched to BIAB AG brewing four or five beers ago and still haven't quite nailed down my process enough to reliably predict my OG like I would like to. It took me that long to find a process I like.

+1

I'm 5-6 batches into AG and still figuring it all out. For your first attempt, you were very close to your target, I'd be happy with it!

 

[unionrdr]

I'm not saying one brewer sucks & the other is a brewing God. far from it. Just stating the facts as they are. Anyway,by my 3rd PM brew,I figured out a way to stabilize my mash temp. that def helps quality-wise. But being able to stir the mash was the biggy. Getting dough balls broken up,& grains evenly wetted made for higher OG's that are within range or a bit more.
So one def has to find a process that works with regard to mashing in order to get reliable numbers. I just get the mash water to 150F,tyhen with the paint strainer bag in place,stor in the grains get them broke up & evenly wetted. When the temp gets to where I want it,off the heat & wrapped up in my thinsulate lined winter hunting coat for the 1 hour mash. The yemp actually goes up 1 degree rather than falling a lot more. Just one idea that can help...