Need help/understanding original gravity

I have a question in regards to reaching the original gravity. I have brewed at least 10 different extract brews, 3 by myself and I have not reached my original gravity. Tonight a brewed an IPA. The recipe including 6lbs of LME, 1 lb of DME and I added an additional 1 1/2lbs of DME. I wanted my beer to have a lighter color so I added the 2 1/2 lbs of DME at the beginnings and the 6 lbs of LME with 10 min left in the 60 min boil. I have recently switched over to a refractometer for my readings. I got a reading of 10.8 plato which is way lower than the specific gravity of 1.050 that the recipe called for even though I added an additional 1 1/2lbs of DME. Any thoughts? I did have one problem during the boil. I normally brew outside on an outside burner but a surprise thunderstorm hit. I had to move inside to resume my boil. I just don’t understand? Do I have to calibrate my refractometer each time I use it? Thanks for your thoughts. Matt

Do u do full boils or top off? If your topping off the wort it is not mixed enough to get accurate reading. If your doing full boils make sure that your refractometer is is calibrated and all your volumes are correct. The markings on buckets can be off by a good amount. Hope this helps.

Cheers :cheers:

Thanks for responding. I’m guessing what you mean is that I do a 2.5 gallon boil then add another 2.5 gallons in the fermenter. Could this throw my gravity reading off?


Your gravity is gonna be correct as long as the amount of dme/lme is correct and final volume is correct. Your reading aren’t coming out correct because it is very hard to mix the top up water and the wort enought to get a correct reading. But don’t worry the yeast will finish mixing it for you.

Thank you. Unfortunately I would have liked to known what my abv turned out but I guess the taste is what I am looking for in the beer.

You can use a calculator to find the OG by the ingredients used. This is a fairly accurate one:
This calculator for ABV:

This is a free recipe builder you might find useful:

Great Flars, I will give it a try!!