Works as well as my Kimax media bottles for pressure sterilizing wort. My pressure canner lets me make enough sterile wort for seven starters at one time.

These are about 9" tall and won't fit in a smaller microwave. It's pretty easy to induce a wort volcano so until you know how things work for the microwave you have I'd advise a foam reducer and/or short bursts of cook time while you watch it like a hawk. Not as convenient as I had hoped but still easier than boil then chill the day before brew day.

Perfect. Just remember your chemistry classes. Don’t take out of autoclave and rinse off the mess. They implode! Not a product flaw just science.

I have been looking for an easy way to make starter wort in advance to simplify the process. I looked into using canning jars but that required a pressure cooker and related canning equipment that I don't have. I thought about using canning jars without a pressure cooker but was too concerned about a possible infection. While it was available I used the FastPitch canned wort which was great but it is no longer available. Then I discovered these bottles and thought I would give them a try.. I bought two for starters (pun intended) and made my first batch: mix DME with water in measuring cup pour into bottle add fermacap to prevent boil over place in microwave for 6-7 minutes until it boiled remove from microwave (use oven mitts) cap and place in refrigerator. Voila ready to use starter wort. When it was time to make a starter I just removed the bottle from the refrigerator and let it warm up to room temperature before using. I made starter wort with my two bottles a number of times without any problems or infections. However a few weeks ago I was making a new starter wort when the bottle exploded after I put the cap on. I had microwaved the starter wort as usual however this time I had a slight boil over in the microwave. I removed the bottle from the microwave put it in the kitchen sink put the cap on and then ran some water over the outside of the bottle to rinse of the boil over wort. BOOM! The bottle shattered into 6-8 large pieces. I know it was probably foolish to rinse the hot bottle off with tap water but I expected it to be able to withstand the temperature change. Live and learn. Despite the explosion I ended up buying 2 more bottles and just finished filling them with starter wort without any problems. The convenience is worth the risk in my opinion. However I will never run tap water over a boiling hot bottle again even if it is borosilicate.

I really like being able to make a large batch of starter wort in advance. I have purchased two and used them both twice with excellent success. I plan on purchasing at least two more. The only con I have is the thin blue top gasket comes off during cleaning. It is a little hard to get back on and there isn't any replacements available yet. I know I'm going to loose one or break it.