First AG beer - help with OG, something off

[TravelingLight]

I did my first AG beer the other day. I went to a buddy's who has been brewing for years and used some of his equipment and his guidance. When I put my recipe into a calculator, it has OG coming in around 1.064, but my hydro sample before pitching yeast was 1.056. I'm trying to figure out if I truly missed my OG or I'm just not setting up the calculator with the correct parameters. I'll give my grain bill (not worried about the hops bill because I'm just trying to figure out what's up with the gravity) and everything I did so hopefully someone more experienced than I am can do some calculations and see where I am off.

12# 2-Row
1.5# Wheat
0.5# Dextrose

Also, I used my buddy's water adjuncts. He's been nerding out on water profiles recently, got a city water profile and did his research. Not sure if it matters, but we used city water and added: 1 campden, 1/3 tsp. calcium chloride, 1/2 tsp. baking soda, 1.5 tsp. gypsum.

- Heated 10 gallons strike water (with adjuncts) to 156*.
- Let it drop down to about 153* then added to mash tun, mashed at 152* for 60 minutes.
- Meanwhile, heated sparge water to 170*. Heated up about 8.5 gallons, but didn't need very much of it.
- After the sacc rest, vorlaufed a few times, then batch sparged to get 7.25 gallons of wort in the kettle.
- Proceeded with 60 minute boil.
- After the boil and after I chilled the wort, I had right at 6.25 gallons of wort in the kettle.
- Dumped to the fermenter and got about 5.75-6 gallons in the fermenter.

I took a gravity sample. The gravity sample was hotter than the calibration temp on the hydrometer, so I used a hydrometer temp converter calculator and got an OG of 1.056. I was expecting at least 1.060 if not 1.064.

I'm fermenting with Giga Vermont. Did a starter and pitched it a little hotter than I would have liked (mid 70s-ish) so it got a slow start, but it's bubbling like hell in the blow off now.

Sorry for rambling, but I wanted to present my entire process to see if someone can see where I'm off. Or, perhaps I'm spot on and I just didn't setup the calculator correctly. Any advice is greatly appreciated. Even if this is a minor screw up on my part, I'm still going all grain from here on!

 

[Pappers_]

Was your recipe in the software set up for 6 gallons (what you actually ended up with in the fermenter)? If it was set up for the standard 5 gallon batch but you ended up with six gallons, that would explain your lower OG.

The other variable you don't mention is what efficiency percentage you used for the recipe in the software. 65% efficiency versus 75% efficiency will change your target OG. For me, I don't need high efficiency, I just need it to be predictable - i.e. the same every time I brew. It took me a while to dial that correct number in, through brewing a few batches and working backwards to find what my actual efficiency was.

 

[Hayden512]

Did you dough in once your strike water hit 153? I'll usually dough in at 10 degrees hotter than my rest temp as I've dropped up to 10 degrees after stirring it all up and making sure there were no dry pockets. You might've mashed too low and didn't get full conversion. Did you take a preboil Gravity?

 

[TravelingLight]

Was your recipe in the software set up for 6 gallons (what you actually ended up with in the fermenter)? If it was set up for the standard 5 gallon batch but you ended up with six gallons, that would explain your lower OG.

The other variable you don't mention is what efficiency percentage you used for the recipe in the software. 65% efficiency versus 75% efficiency will change your target OG. For me, I don't need high efficiency, I just need it to be predictable - i.e. the same every time I brew. It took me a while to dial that correct number in, through brewing a few batches and working backwards to find what my actual efficiency was.

I think I used 75% efficiency because that was the preset number and I wasn't sure what to change it to, if to change it at all. As far as volumes, the calculator I was using had fields for boil size and kettle volume of wort. I tried to be fairly accurate with those.

Did you dough in once your strike water hit 153? I'll usually dough in at 10 degrees hotter than my rest temp as I've dropped up to 10 degrees after stirring it all up and making sure there were no dry pockets. You might've mashed too low and didn't get full conversion. Did you take a preboil Gravity?

I doughed in with the strike water at 156. Of note: the mash tun was preheated because we were doing back to back beers, he had just mashed in so it was still hot. After stirring and busting it all up, mash was at 152. After the sacc rest I hadn't lost any temp, maybe a half degree, tops. I did not take a preboil gravity and I am now kicking myself for not doing it. He never does it because he's brewed so much. But I should have since it was my first AG beer but I just forgot.

 

[doug293cz]

Did you use a water calculator to predict your mash pH (I assume you didn't actually measure the pH)? When using all light colored malts, the addition of baking soda looks quite odd. Normally with an all light colored grist you need to add acid (or acid malt) to get the pH into a 5.3 - 5.5 range. Your pH was likely excessively high, which could have affected your conversion efficiency. There is no way to verify conversion efficiency without more complete volume and SG measurements.

Brew on

 

[Pappers_]

I think I used 75% efficiency because that was the preset number and I wasn't sure what to change it to, if to change it at all.

So one possible answer is that 75% isn't the correct efficiency for your process, grain, and equipment. With Beersmith, you can calculate your actual efficiency afterwards, and use that actual number for your next batch.

As far as volumes, the calculator I was using had fields for boil size and kettle volume of wort. I tried to be fairly accurate with those.

Maybe its called 'batch size' or something like that. Its a basic variable that has to be included somewhere, even if its only an assumption. If you ended up with a six gallon batch but the software was set to another batch size, your target OG would be off from your actual OG.

 

[PlinyTheMiddleAged]

I took a gravity sample. The gravity sample was hotter than the calibration temp on the hydrometer, so I used a hydrometer temp converter calculator and got an OG of 1.056. I was expecting at least 1.060 if not 1.064.

How hot was your sample? The correction factors can supposedly be pretty far off with high temperatures. I try to get within a few degrees F before I measure a sample with a hydrometer.

 

[TravelingLight]

Did you use a water calculator to predict your mash pH (I assume you didn't actually measure the pH)? When using all light colored malts, the addition of baking soda looks quite odd. Normally with an all light colored grist you need to add acid (or acid malt) to get the pH into a 5.3 - 5.5 range. Your pH was likely excessively high, which could have affected your conversion efficiency. There is no way to verify conversion efficiency without more complete volume and SG measurements.

Brew on

Great points. I did not check the ph. I should and could have. I own a ph meter, just didn't have it with me. Also had no idea about adding acid for light grist. Live and learn!

So one possible answer is that 75% isn't the correct efficiency for your process, grain, and equipment. With Beersmith, you can calculate your actual efficiency afterwards, and use that actual number for your next batch.



Maybe its called 'batch size' or something like that. Its a basic variable that has to be included somewhere, even if its only an assumption. If you ended up with a six gallon batch but the software was set to another batch size, your target OG would be off from your actual OG.

Makes sense. Thanks. I figured the more and more I get into AG brewing the better I'll learn my process and nuances and get better calculations.

How hot was your sample? The correction factors can supposedly be pretty far off with high temperatures. I try to get within a few degrees F before I measure a sample with a hydrometer.

I can't remember now. But that's great advice. I had never used a hydro temp calculator before so I had no idea they can be pretty off. That may very well be one of my issues. I wanna say the hydro sample was closer to 80* when I checked it. And the calculator for an 80* sample only added about 2 points.

I'm thinking it could be a combination of all of the above. Regardless, it's fermenting and it'll be beer. It should finish pretty low with that yeast. Thanks guys.

ETA: I just realized something. I think my hydro sample was actually pretty damn close to what it should be, temp wise. I just remembered when it was still hot I put the sample in the fridge to cool down and I checked it when it was closer to 60 degrees. So maybe it's not the temp difference.

 

[MapleGroveAleworks]

Simple answer most likely. You told BeerSmith that your system runs at 75% efficiency, where you run at more like 65%. Change that for next batch and you'll likely hit your OG. Every first batch is like that unless you're incredibly lucky.

 

[TravelingLight]

Simple answer most likely. You told BeerSmith that your system runs at 75% efficiency, where you run at more like 65%. Change that for next batch and you'll likely hit your OG. Every first batch is like that unless you're incredibly lucky.

I will be damned you nailed it. I just went back to the calculator and put everything in and changed it to 65% efficiency. Nailed the OG at 1.056. Thank you SO much.

 

[MapleGroveAleworks]

I will be damned you nailed it. I just went back to the calculator and put everything in and changed it to 65% efficiency. Nailed the OG at 1.056. Thank you SO much.

No problem, glad to help. 65% is pretty good too. It's way more important to be able to consistently hit your numbers every time than having a high efficiency %