High OG

[BrettV]

So I guess you can't really call this a "problem" per se, but I brewed a winter warmer style beer today that should have come in around 1060 (according to Brewtoad,) but actually measured at about 1071. The 1060 reading was assuming an efficiency of 75%, and even if I bump the software to 100% I still only get 1069.

Recipe:

3.5# Maris Otter
3.3# Amber LME
1.0# Pilsen DME
0.5# Crystal 120L
0.5# Crystal 60L
0.25# Flaked wheat
0.1# Chocolate malt

1 oz. Willamette 6.4% AA 60 mins

1968 London ESB (created a 1L starter yesterday)

Added some extra spices and whirlfloc at 10 mins, but that's inconsequential to gravity, so I'll skip the amounts. I mashed all the grain in 2.5 gallons of water at around 152-154 for an hour. I "tea-bag" sparged (a la Deathbrewer's thread) in 1.5 gallons of water that I heated to about 162. Teabagged it, let it sit for 10 mins, teabagged again and combined the two pots. Brought it to a boil, added hops, set timer. With 10 mins left I added all the malt extract and spices. Cooled it to 68 with a copper wort chiller, dumped into a 6 gallon carboy, and topped up to 5 gallons with cold pre-boiled water. Shook the ever-loving hell out of it for 3 minutes, poured off a sample, added my yeast starter. Temperature of the sample was 68.5 at the time of the reading and it came out to 1.070, which using the temp difference table means the actual gravity is about 1.071. To ME, it seems everything I did was on point. I've brewed partial mash beers many times before this exact same way, and usually undershoot the predicted OG by a little. I'm not sweating it; it just means I might have a higher ABV than expected, but I'm at a loss for how I got such a high OG.

 

[h-bar]

Did you weigh the grains yourself or did someone at the LHBS do it? Maybe they accidentally gave you a little more grain? One time there was a new guy at my LHBS who got my grains, and I think he grabbed some of the wrong stuff because my beer was much darker than it should have been...

Anyway, that's the only thing I can think of. Unless your hydrometer isn't reading correctly.

 

[BrettV]

I weighed them myself at the LHBS. I double checked the weight, and it came in a hair under 5 lbs, which is correct according to the recipe.

 

[IL1kebeer]

What was your preboil gravity?

Are you 100% sure of the accuracy of your volumes in the kettle?

 

[JLem]

Since you topped off with fresh water, you likely had a stratified wort and your reading was inaccurate. It is exceptionally difficult to thoroughly mix wort after topping off...no matter how well you think you did.

 

[BrettV]

IL1kebeer - I don't know what the preboil gravity was; it's not a reading I've ever taken. Because I add extract and top-up water later on, I've never felt like that reading would do me much good. Also, can you do that with a hydrometer? I thought you needed a refractometer to take a pre-boil gravity reading since the temperature would still be quite high right after the mash and sparge. I'm fairly certain about the water measurements; I use a measuring pitcher to measure the water. My kettle doesn't have any kind of measurement markings.

JLem - Interesting. I've been doing partial mashes with topped up water for a while, and generally my readings are pretty close to the estimated OG or even a little under. There was only one other brew where I got a wildly inaccurate reading. Since I can't really move to all-grain in my kitchen, and I'll likely be doing partial mashes like this for the foreseeable future, is there a way to overcome the stratified wort?

 

[IL1kebeer]

I'm fairly certain about the water measurements; I use a measuring pitcher to measure the water. My kettle doesn't have any kind of measurement markings.

Are you 100% certain of your post boil volume? If so I would take a hydrometer reading after the boil before you top off and then just do the dilution math to get your OG. This will prevent a skewed reading from the wort and top off water not being mixed.

I'm too lazy to type out the equation so here is a link, use the bottom calculator: http://www.brewersfriend.com/dilution-and-boiloff-gravity-calculator/

 

[BrettV]

Thanks for the resource. I'm not currently sure of my post-boil volumes because my kettle doesn't have measurement markings on it, and I don't know what the exact evaporation rate is, but that's good info nonetheless. It won't be the end of the world not to know the true ABV on this one. I was careful and methodical today, so the chance of it not turning out is pretty slim.

 

[IL1kebeer]

Thanks for the resource. I'm not currently sure of my post-boil volumes because my kettle doesn't have measurement markings on it, and I don't know what the exact evaporation rate is, but that's good info nonetheless. It won't be the end of the world not to know the true ABV on this one. I was careful and methodical today, so the chance of it not turning out is pretty slim.

Easy. If you have some spare time then boil the same amount of water that you did for your last batch. After 1 hour kill the boil and cool the water. After the water is cool then find some way to measure it. From there you can figure your post boil volume from your last batch by subtracting your newly figured out boil off rate from the preboil volume of that batch. You really won't be able to do much since you didn't take a hydrometer reading before topping off, but if you want to ballpark it you can estimate a preboil gravity based on your grainbill and work the boil off calculator to get a post boil gravity. It's quite a bit of work but the value of dialing in your system is priceless.

Keep in mind that there are factors that affect your evaporation rate. These factors include how vigorously you boil and the current humidity. I wouldn't worry about it too much but just keep it in mind in case you notice some variations in the future.

 

[RM-MN]

IL1kebeer - I don't know what the preboil gravity was; it's not a reading I've ever taken. Because I add extract and top-up water later on, I've never felt like that reading would do me much good. Also, can you do that with a hydrometer? I thought you needed a refractometer to take a pre-boil gravity reading since the temperature would still be quite high right after the mash and sparge. I'm fairly certain about the water measurements; I use a measuring pitcher to measure the water. My kettle doesn't have any kind of measurement markings.

JLem - Interesting. I've been doing partial mashes with topped up water for a while, and generally my readings are pretty close to the estimated OG or even a little under. There was only one other brew where I got a wildly inaccurate reading. Since I can't really move to all-grain in my kitchen, and I'll likely be doing partial mashes like this for the foreseeable future, is there a way to overcome the stratified wort?

Why can you not move to all grain in your kitchen? I've been doing all grain in my kitchen for years. I happen to be blessed with an electric stove with a very high output burner but if you can boil 3 gallons on your stove you can do all grain 2 1/2 gallon batches. You could even do 1 gallon all grain if your stove is too weak to boil 3 gallons. Check out the BIAB method.

 

[JLem]

JLem - Interesting. I've been doing partial mashes with topped up water for a while, and generally my readings are pretty close to the estimated OG or even a little under. There was only one other brew where I got a wildly inaccurate reading. Since I can't really move to all-grain in my kitchen, and I'll likely be doing partial mashes like this for the foreseeable future, is there a way to overcome the stratified wort?

It is very tough to mix wort and top off water - like others have suggested your best bet is probably to measure your postboil gravity and then calculate the dilution. If you ever move to an aeration system - I use an aquarium pump with cintered stone - the aeration process will do a better job of mixing up the wort than shaking it.

 

[BrettV]

Why can you not move to all grain in your kitchen? I've been doing all grain in my kitchen for years. I happen to be blessed with an electric stove with a very high output burner but if you can boil 3 gallons on your stove you can do all grain 2 1/2 gallon batches. You could even do 1 gallon all grain if your stove is too weak to boil 3 gallons. Check out the BIAB method.

Yeah, I have considered doing smaller all-grain batches, but I'd need to get another small fermenter, since I don't think it would be wise to ferment 1 or 2 gallons in a 5 or 6 gallon carboy.

All if this could be solved if I would just leave New York City, and go someplace where I could brew outside and actually have room to store more equipment. Being a Brooklyn brewer is a PITA! :cross:

 

[BrettV]

It is very tough to mix wort and top off water - like others have suggested your best bet is probably to measure your postboil gravity and then calculate the dilution. If you ever move to an aeration system - I use an aquarium pump with cintered stone - the aeration process will do a better job of mixing up the wort than shaking it.

This is definitely good to know, and probably explains any crazy deviation from estimated OG. My system is still pretty primitive right now, even after 3 years of brewing. Money and space prevent me from really amping up just yet. This aeration system you speak of, do you have a link to a guide you used for creating it? I'm sure I can just google it, too, but if you had a particular method you found effective it'd be nice to know.

 

[RM-MN]

Yeah, I have considered doing smaller all-grain batches, but I'd need to get another small fermenter, since I don't think it would be wise to ferment 1 or 2 gallons in a 5 or 6 gallon carboy.

All if this could be solved if I would just leave New York City, and go someplace where I could brew outside and actually have room to store more equipment. Being a Brooklyn brewer is a PITA! :cross:

I do a lot of 2 1/2 gallon batches all grain and ferment them in my 6 1/2 gallon bucket fermenter. Works fine for me.:rockin:

 

[ballsy]

Since you topped off with fresh water, you likely had a stratified wort and your reading was inaccurate. It is exceptionally difficult to thoroughly mix wort after topping off...no matter how well you think you did.

This is what I was thinking as well. Although the weight of the base grains being a little heavy and the top off water levels being on low side are also on the list!