Large Batches (8 lbs.) = Air Bubbles? Why?

[Jan V]

I've been CP soaping for 20 years. Never had a problem with air bubbles until now. The only difference is I'm doing 8-9 pound batches now. Sames oils, temps between 110-125, lye water poured down bucket side, burp & pulse stick blender..... everything I've always done with 2-6 lb batches. But, I have air bubbles in every batch even with extra care used after the first batches. Can't even see the air bubbles until after cure when each bar feels like it has baby acne! I'm open to any suggestions and ideas!

 

[DeeAnna]

Are you sure they're air bubbles and not stearic soap spots? A pic would be helpful.

You should post your recipe and method to get the best advice.

 

[BrewerGeorge]

If you do confirm that it's truly bubbles, I would imagine that the larger batch size makes it difficult for you to remove all the bubbles via the typical "slam" method.

Take a cue from plaster casters and look into some kind of vibratory table to help you get the bubbles out.

 

[Jan V]

 

[soapmaker]

Sure looks like air bubbles. Mine do that too.

 

[dibbles]

Are you by any chance using a new or different stick blender?

 

[dixiedragon]

I've noticed with a larger batch, things tend to move a bit quicker - more heat I assume? Maybe try dropping your temps by 5-10 degrees.

 

[soapmaker]

Are you by any chance using a new or different stick blender?

This may be a clue. I have a stick blender that I stopped using because it made air bubbles even if you burped it, it somehow introduced air.

 

[Jan V]

Vibrating table is an interesting concept. Would have to do this to the solution before I started to stick blend. I like his homemade one but he's working with a small mold ... I'd need a powerful vibration to deal with 12+ lbs. solution.

I'm just trying to determine why the larger quantity of soap would make any difference in air bubbles. If anything, I'd think it would be even less of a problem just because there's so much oil/lye water that is being blended.

I've used my tried and true stick blender. Tried a different one, but the resulting batch was worse yet.

Maybe temp is the key, as is being suggested here.

 

[lenarenee]

Have your molds changed? Are you pouring a large pot of batter into one large mold, or several smaller molds?

 

[shunt2011]

What are you using to cut the soap? Sometimes my wire cutter causes little bumps on the soap. Doesn’t leave holes just little bumps. I can polish them out if I choose to but I just leave them. Doesn’t happen often. I make some batches 15 Lathers lbs at a time.

 

[BrewerGeorge]

Vibrating table is an interesting concept. Would have to do this to the solution before I started to stick blend. I like his homemade one but he's working with a small mold ... I'd need a powerful vibration to deal with 12+ lbs. solution.

...

I would suspect that the massage device he's hacked is strong enough for your purposes. You'd just need a table large and strong enough to hold the full mold. And the idea is to vibrate the mold after it's filled with soap batter as a replacement for knocking the mold on the countertop.

My guess as to why this is happening now with the larger amount is that this knockdown step is impossible or more difficult because of the size and weight of the filled mold. ARE you able to bang it around like you do a small mold?

 

[DeeAnna]

Or there's some additive in the recipe that is evolving gas during saponification?

 

[SaltedFig]

That would make sense, especially if the temperature is up.

It could be dissolved gases (in the water to start with) coming out of solution, if the temperature is approaching boiling point (of water).

Lowering the temperature a little (to account for the extra heat in the larger batch) and using BG's vibration table idea should sort it out.

 

[Jan V]

No additives other than colorant before FO is added. All stirred in by hand. One large pot into one large mold.

I'm going to try lowering the temp with my next batch to see if that makes any difference. Thanks for all the input.

 

[lrpolillo]

What are you using to cut the soap? Sometimes my wire cutter causes little bumps on the soap. Doesn’t leave holes just little bumps. I can polish them out if I choose to but I just leave them. Doesn’t happen often. I make some batches 15 Lathers lbs at a time.

My cutter leaves bumps too sometimes. It all works out after cleaning up the soap