Ballsd up my first brew - low OG

[Dionys]

Well, tried my first brew ever and went for a 4.5L target size, all-grain BIAB. Completely messed up the brew, but had a great time and hopefully the end result won't be too vomit-inducing!

Tried a Kolsch recipe, Black Widow Kolsch. Didn't buy enough grain and bought the wrong grain (Carapils instead of Pilsner), so went with 50/50 Carapils and Wheat Malt for a total of 1.12 kilograms. Hopped with Hersbrucker and Saaz. Mashed for 85 mins, water looked a bit low so topped up with water before taking an OG....

OG post boil and cool? 1.018. Estimated ABV 3.3% on Beersmith
I think this is a combination of not stirring the grains inside the bag at all, not stirring in general, diluting the post-mash volume down and just general inexperience.

Currently fermenting away nicely. Given the low OG, is this drinkable? Am I right in thinking this will finish fermenting a bit earlier than the three weeks suggested on the forums? I was planning on doing a table sugar bottle carbonation with the values suggested by Beersmith: about 36g of sugar, is this still advisable?

Thanks!

Edit: units

 

[The_Bishop]

Uh, carapils is not a substitute for pilsner malt. It's a form of 'crystal' or dextrine malt and contains a lot of unfermentables. And 1.12 grams? Of grain?

Kolsch is a tough beer for a first brew. Nothing for flaws to hide behind and pretty water dependent. Maybe try again with a simple pale ale.

 

[Dionys]

Uh, carapils is not a substitute for pilsner malt. It's a form of 'crystal' or dextrine malt and contains a lot of unfermentables. And 1.12 grams? Of grain?.

Thank you for your helpful reply. Did you see the part of my post where is said that I "bought the wrong grain (Carapils instead of Pilsner)"?

Are you able to answer any of the specific questions that I asked in my original post?

 

[bucketnative]

I put the numbers you quoted for grains and wort volume into Brewer's Friend, and you should have come up with an OG of about 1.056 post-boil. That means you had about 15% efficiency. Stirring of the grains in the bag is generally not an issue. Even if you made a dilution error, you would have had to be off by more than 300 % to finish that low in OG.

That leads me to ask a couple of questions in order to help you figure out what went wrong.

1. Did you crush the grains prior to mashing? Crush is usually the number one issue with poor conversion/extraction of sugars during mashing.

2. What was your mash temperature? Typically, it should be in the range of 62 °C to 70 °C.

It'll probably be finished a little earlier, but it depends on temperature, pitch rate, etc... Measuring the gravity is one way to tell. Steady gravity over 3 days, it's done. If you don't want to sacrifice samples for gravity, then give it at least two weeks. That will allow time for the yeast to settle.

To answer your question about priming of the bottles, an addition of 36 g table sugar to a 4.5 L batch will give you 3.0 vol CO2, which is on the high side. I would target something around 27 g, which would give you about 2.5 vol CO2.

 

[Dionys]

I put the numbers you quoted for grains and wort volume into Brewer's Friend, and you should have come up with an OG of about 1.056 post-boil. That means you had about 15% efficiency. Stirring of the grains in the bag is generally not an issue. Even if you made a dilution error, you would have had to be off by more than 300 % to finish that low in OG.

That leads me to ask a couple of questions in order to help you figure out what went wrong.

1. Did you crush the grains prior to mashing? Crush is usually the number one issue with poor conversion/extraction of sugars during mashing.

2. What was your mash temperature? Typically, it should be in the range of 62 °C to 70 °C.

It'll probably be finished a little earlier, but it depends on temperature, pitch rate, etc... Measuring the gravity is one way to tell. Steady gravity over 3 days, it's done. If you don't want to sacrifice samples for gravity, then give it at least two weeks. That will allow time for the yeast to settle.

To answer your question about priming of the bottles, an addition of 36 g table sugar to a 4.5 L batch will give you 3.0 vol CO2, which is on the high side. I would target something around 27 g, which would give you about 2.5 vol CO2.

Thanks very much for your reply.

Beersmith calculated OG for the exact numbers I put in was 1.042, measured for 1.013, which gave efficency of 23. Clearly something has gone wrong.

1. Grain was bought from http://www.lovebrewing.co.uk/beer/malt/grain/
My first time buying - I did ask the salesperson who stated that they were crushed but I couldn't tell you for definite how well they were crushed. They looked okay based on what I googled (crushed vs uncrushed).

2. Mash temperature was 71C 'strike' (I think that is the right terminology but maybe wrong) and 66.7C for 75 mins before a 75.6 mashout for 10 mins. There was definitely some temperature fluctuation in the mash, probably hotter than what the target was. I was sampling temperatures right from the top and didn't mix the water around much, but found towards the end it was more like 75 towards the bottom. Maybe some enzyme inactivation due to the heat?

 

[Pappers_]

I don't think you had enough diastatic power with that grain bill. Carapils has none, as far as I know, and wheat malt is typically about half as much as 2 row, pilsner or munich, I believe. Basically, you brewed a beer without any base grain, which is the core of your problem. The enzymatic activity necessary to mash was reduced, so you got very little sugars out of your mash, hence your low gravity.

As for your questions, assuming your gravity reading was correct, I would dump the beer and try again.

 

[Pappers_]

Thank you for your helpful reply. Did you see the part of my post where is said that I "bought the wrong grain (Carapils instead of Pilsner)"?

Are you able to answer any of the specific questions that I asked in my original post?

He was being helpful. Your sarcasm isn't appreciated. Thread closed and warning given.