National Homebrew Club Ireland

General Discussions => Chit Chat => Topic started by: bbreal on July 23, 2023, 07:40:32 PM

Title: OG Target
Post by: bbreal on July 23, 2023, 07:40:32 PM
Hi, question here for anyone that can help. Had a brew with OG target of 1.051. I got 1.045 after boil. Is there anything I can do after sparging that can increase the OG. I heard I can get more sugars from the grains by adding more water and add to increase the OG. Anyone do this, what calculations do you use etc.
Not sure if gravity readings are the same before and after boil etc.
May seem a silly question.
Thanks.
Title: Re: OG Target
Post by: SureLook on July 23, 2023, 09:57:52 PM
So there's a few factors that may contribute here. Depending on your boil off rate an OG of 1.045 pre-boil seems reasonable to hit your target.

In general, the more you sparge the more sugars you will rinse from the grains. Only thing is you'll have to boil off more liquid (before adding your bittering hops) to compensate for the extra water used in sparging.It's good practice to take a pre and post boil gravity measurement also, these allow you to take corrective action in real time if something looks off. To answer your question brewing software like Brewfather and Brewers friend will have online calculators which will tell you exactly how much to boil off to ger to a desired FG.
Title: Re: OG Target
Post by: bbreal on July 23, 2023, 10:53:45 PM
Thanks for reply. If you get a chance can you send on screen shot of what I've to do to reach the OG I need. I did bit of research on a few websites and not 100% of what needs doing. I've basic grainfather. My OG after boil was 1.045. I assumed this was so and I couldn't change to get 1.051 etc. I'd love to reach or get close to expected OG. 👍
Title: Re: OG Target
Post by: SureLook on July 24, 2023, 08:36:48 PM
I'd need to know your current pre-boil volume to be able to calculate the amount of liquid you need to boil off to get from 1.045 to 1.051. Can send you on a tbe details if you provide that.
Title: Re: OG Target
Post by: bbreal on July 26, 2023, 06:58:41 PM
Can't remember to be honest. I don't want to guess. Can you send on calculation for GF 23l batch volumn. Think GF are all around 23l. Thanks.
Title: Re: OG Target
Post by: SureLook on July 28, 2023, 02:04:56 PM
So assuming a boil off rate of 3.5 L/hr (that's what I have, however this will vary quite a bit depending on system) you'd need to have a pre-boil volume of wort of 27.5 L, boil for 1 hour to get from 1.045 to 1.051.

This assumres the amount going into the fermenter is 23L (and not loses occur during transfer, which the inherently will, unfortunately). Its quite a system specific calculation.
Title: Re: OG Target
Post by: bbreal on July 28, 2023, 02:17:01 PM
Thanks for the reply, I was fairly regimental when it came to boil for 1hr, I stopped it at that and completed it. I'll need to be more experimental etc. I never checked gravity before or during the boil, I have refractometer which has brix scale so I can use this for taking smaller samples and taking the SG from that. Beer still tastes good, just trying to get tad better.
Title: Re: OG Target
Post by: DEMPSEY on August 01, 2023, 02:57:52 AM
A target is just that, a target. If you are using a software like Beersmith3 and you enter a recipe,the rate of efficiency will give you a target. If you do a batch and your numbers are different, and you have had a normal brewday,then your rate of efficiency is not the same. By going to your Beersmith3 software and adjusting the efficiency number until you match your actual number, you will then know what your efficiency number will be for future batches.