Wort sample from top or bottom of boil kettle

[RTHayes63]

I've got a 15bbl BK. I'm getting about a .5 Brix differential between a sample pulled from the top compared to the sample pulled from the bottom of the tank. Question is what reading do I go with?

thanks,
Todd







Peoria Brewing Company

[NHBrewer23]

Hi Todd,

I have seen this before. You are getting stratification, which I'm sure your well aware of... What types of samples are you taking? Pre-Boil or Post-Boil? For Pre-boil samples, I like to take my sample using a ladle when the wort is around 209-210 and rolling along the sides. Since my first hop addition isn't until 30 minutes into the boil (60 minute charge during a 90 minute boil), I usually have enough time to get an "idea" as to where my wort gravity is at. I typically use a refractometer for my pre-boil due to its speed in addition to a hydrometer sample. The hydrometer sample is cooled within an ice bath during the boil. This does not provide me a whole lot of room to make any boil adjustments. I tend to trust a hydrometer over a refractometer though.

For post-boil samples, I take my sample inline from the Heat-X to the fermenter using a T-fitting and valve arrangement. I typically double batch my fermenters so if my gravity is off on the first batch, I'll correct it with the second. Sometimes with the first batch, I'll just take my sample from the fermenter prior to pitching the yeast. This should provide you a homogeneous sample as well.

To get a "good" sample from the kettle, I would grab a sample right before you cut off heat to your kettle. This way the wort is still rolling and most likely mixed as much as it will be.

[RTHayes63]

Thanks, I've been getting preboil and OG. I just increased the volumes of our batches and my efficiency seems to have dropped by 4% Trying to find a cause.

thanks,
Todd

[NHBrewer23]

How much additional grain have you added to your mash tun with the increase in collected volume? Does your mash/lauter tun have rakes? You may be experiencing channeling or bed compaction due to the increase in grain weight. If you have rakes, try cutting your bed once or twice during runoff.

What type of water adjustments have you made within your mash tun? Did you increase your strike volume or just your sparge volume?

[RTHayes63]

I've only added about 6% more grain roughly 150 lbs. I have adjusted my strike volume to compensate. I don't have the vertical raked on the rake in my mash tun, just the large horizontal sweeper arm. I'm down to 82% efficient on a 570 gallon batch and 86% on a 540 gallon batch.