question regarding beer kits

[klasikrkade]

I having been brewing 7 gallon full boils using recipes in the jamil book "brewing classic styles. All recipes are designed around 7 gallons which after boil off leaves you with 6 gallons in the brewpot. Then 5.5 gallons after racking into the primary. All great.

My question is when using the 5 gallon beer kits from places such as Midwest, northern brewer etc how much water should I be starting with when attempting to use these kits? As I said I am used to using 7 gallons to start with.

Tonight I brewed a Midwest Surly furious clone called ferocious. I used 6.5 gallons and ended up with an OG of only a little over 1.050 after racking 5.5 into the primary where it should be in the 1.065 range. I can only assume that it is a bit too diluted and this is what is causing the low reading.

Any insight, ideas?

 

[glick]

Assuming you're using an extract kit designed for 5 gallons batch size you shouldn't have more then 5 gallons going into the primary. My guess is that you used too much water causing the missed OG. I think that the typical boil off rate is 10% per hour so I would suggest starting with just 5.5 gallons as your preboil volume. You could add some DME to the fermenter to increase your gravity to get you back on track.

 

[klasikrkade]

Can I add the DME now that the yeast is already in the fermenter?

 

[signpost]

Yes, you can add DME if you want to get to the intended gravity. But since the yeast is going, you won't be able to get a useful gravity reading. You'll just have to calculate what the OG would be by adding your measured OG and the extra gravity from the DME you add.

Is there a reason you are losing so much volume when you transfer? Is it because your equipment doesn't allow you to transfer completely? Or is it just because the brewing classic styles recipes took that loss into account?

If you are doing extract, and you know you'll be losing that much volume, you can just add more DME from the start. And if you are doing all-grain, you can just add more base malt.

My guess is that this problem is just a matter of you getting to know your equipment well enough to adjust recipes to compensate for losses or other idiosyncrasies.

 

[klasikrkade]

Thanks for the reply. Well the jamil receipes account for 1 gallon of boil off over the 60 minute boils and then 5.5 of the 6 gallons into the fermenter due to trub when racking to primary.

I am thinking as glick pointed out that I simply started with too much water and after boil was left with 5.5 gallons rather than the 5.0 that these kits are designed around. Perhaps starting with 5.75 instead of 6.5 gallons may result in a more targeted final gravity.

 

[MKBoitnott]

Assuming you're using an extract kit designed for 5 gallons batch size you shouldn't have more then 5 gallons going into the primary. My guess is that you used too much water causing the missed OG. I think that the typical boil off rate is 10% per hour so I would suggest starting with just 5.5 gallons as your preboil volume. You could add some DME to the fermenter to increase your gravity to get you back on track.

While the 10% guideline usually works, I would use caution in this example. A percentage of boil off implies that the boil off is affected by you volume. It really isn't. The usual contributor is the size of your boil kettle. 10% is misleading because it implies that you will get less loss with a 5 gallon batch than you would from a 10 gallon batch using the same kettle. It's about the surface area of the boil so having a bigger kettle results in more loss.

It appears the OP had a 1 to 1.5 gallon boil off using the same kettle. I would recommend using that number regardless of the batch size.

 

[signpost]

Anytime you leave a half gallon in the kettle, you are going to be short on your OG when working from a kit. Even if the volume in your primary is right on. If you are siphoning or using a false bottom/valve to get from your kettle to the primary, just make sure to get as much of the wort as possible.